HeatNet Smith User Manual

Page 1

firmware version

Also read and follow:

3187269

This manual is intended only for use by a qualified heating installer/technician. Read and follow this manual, all supplements and related instructional information provided with the boiler. Install, start and service the boiler only in the sequence and methods given in these instructions. Failure to do so can result in severe personal injury, death or substantial property damage.

Do not use the boiler during construction. Construction dust and particulate, particularly drywall dust, will cause contamination of the burner, resulting in possible severe personal injury, death or substantial property damage. The boiler can only be operated with a dust-free air supply. Follow the instruction manual procedures to duct air to the boiler air intake. If the boiler has been contaminated by operation with contaminated air, follow the instruction manual guidelines to clean, repair or replace the boiler if necessary.

Affix these instructions near to the boiler. Instruct the building owner to retain the instructions for future use by a qualified service technician, and to follow all guidelines in the User’s Information Manual.

SHC-IOM-1

Smith

Modulating Hot Water Boilers

Series

manual

Control adjustment and operation instructions for Smith

1.38

This instruction manual applies only to Smith firmware version 1.38.

Smith Series Hot Water Boiler Installation and Operating Instructions

Page 2

TABLE OF CONTENTS

HeatNet Control REV 1.38-1

TABLE OF CONTENTS

TABLE OF CONTENTS .............................................................................................................................. 2

Introduction ................................................................................................................................................ 4

HE SMTIH-SERIES HEATNET CONTROL

Features & Specifications ......................................................................................................................... 6

EATURES OVERVIEW

........................................................................................................................................................................ 6

Specifications ............................................................................................................................................ 7

Components & Accessories ..................................................................................................................... 8

SETUP & OPERATION ............................................................................................................................... 9

ASIC MULTI BOILER SYSTEM OPERATION

IXED BOILER TYPES USING PRIORITY SETS

IXED BOILER SYSTEM OPERATION

TART/STOP PRIORITY CONDITIONS

ELECTING MIXED BOILERS

IXED SYSTEM EXAMPLES

ASE LOADING, RELAY CONTROL

ETTING UP BASE LOADING

.............................................................................................................................................................. 13

................................................................................................................................................................ 13

............................................................................................................................................................... 18

.............................................................................................................................................. 4

............................................................................................................................................ 9

..................................................................................................................................... 10

................................................................................................................................................... 10

.................................................................................................................................................. 11

..................................................................................................................................................... 17

Heating Control Methods ........................................................................................................................ 20

EATING METHOD

PERATING LIMIT

NPUT PRIORITIES

EATING METHOD 1

EATING METHOD 2

EATING METHOD 3

EATING METHOD 4 AA INPUT

EATING METHOD 5

1 ......................................................................................................................................................................... 20

2 ......................................................................................................................................................................... 20

3 ......................................................................................................................................................................... 20

4 ......................................................................................................................................................................... 20

5 ......................................................................................................................................................................... 20

............................................................................................................................................................................. 20

............................................................................................................................................................................ 20

HEAT DEMAND .............................................................................................................................................. 21

STAGE C

4-20

MODBUS

ONTROL

MA CONTROL

.......................................................................................................................................................... 22

COMMUNICATIONS

T1-T2 ................................................................................................................................... 22

.............................................................................................................................................. 22

.............................................................................................................................. 22

Using The 4-20mA Input (OPTIONAL) .................................................................................................... 23

Circulator Pump Options ........................................................................................................................ 24

Auxiliary Function Options ..................................................................................................................... 25

Outdoor Reset .......................................................................................................................................... 25

Sensors .................................................................................................................................................... 26

Security .................................................................................................................................................... 26

Diagnostics .............................................................................................................................................. 26

Communications ...................................................................................................................................... 26

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TABLE OF CONTENTS HeatNet Control REV 1.38-1

Failsafe Modes ......................................................................................................................................... 26

FAILSAFE REQUIREMENTS: ....................................................................................................................................................... 26

Domestic Hot Water Methods ................................................................................................................. 28

DHW METHOD 1: DHW T

DHW METHOD 1A: DHW H

DHW METHOD 1B: C

DHW METHOD 2: DHW H

DHW METHOD 3: S

DHW METHOD 4: DHW

ANK SENSOR INPUT

EATING

ONLY

OMBO

DHW

AND SPACE HEATING USING A

EADER SENSOR INPUT

PACE HEATING WITH

USING DIRECT CONTROL

................................................................................................................................ 28

USING A SINGLE BOILER OR A

............................................................................................................................. 30

DHW O

VERRIDE

............................................................................................................................ 31

............................................................................................................... 30

DHW MASTER

MASTER B

AND MEMBER BOILER(S) EMPLOYING

OILER AND MEMBER BOILER(S) EMPLOYING

H-NET ... 28

H-NET ............. 29

Stack Temperature Monitoring ............................................................................................................... 31

Wiring Connections ................................................................................................................................. 33

Calibration ................................................................................................................................................ 44

Log Entry .................................................................................................................................................. 45

Default Settings & Menu Item Descriptions — SETUP .......................................................................... 46

Default Settings & Menu Item Descriptions — ADVANCED SETUP ..................................................... 50

MODBUS Communications ..................................................................................................................... 54

Troubleshooting ...................................................................................................................................... 61

Smith HeatNet Control Run Screen ........................................................................................................ 65

* Status Information ................................................................................................................................... 3

TATUS INFORMATION SCREENS

.......................................................................................................................................................... 3

Smith HeatNet Control Menu Tree — Smith Version 1.38 ..................................................................... 68

Smith HeatNet Control Advanced Menu Tree — Smith Version 1.38

........................................................ 69

Worksheet ................................................................................................................................................ 70

Thermistor Resistance/Temperature Table ............................................................................................ 73

Status Screen Fault Display .................................................................................................................... 75

Line 4 Log Entries: .................................................................................................................................. 78

Information contained in this publication regarding device applications and the like

is provided only for your convenience and may be superseded by updates. It is

your responsibility to ensure that your application meets with your specifications.

SMITH MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND

WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR

OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT

LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE,

MERCHANTABILITY OR FITNESS FOR PURPOSE.

http://www.smithboiler.com/

Page 3

The Smith name and logo, Hydrotherm name and logo, Mestek name and

logo, HeatNet, and H-Net name and logo are registered trademarks of

Mestek, Incorporated in the U.S.A. and other countries.

BACnet is a registered trademark of ASHRAE. LonWorks is a registered

trademark of Echelon Corporation. All trademarks mentioned herein are

property of their respective companies.

Rights Reserved.

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FEATURES & SPECIFICATIONS HeatNet Control REV 1.38-1

Introduction

The S

MITH

HeatNet Control

The Smith HeatNet boiler control is designed to provide the Smith Water boilers with an integrated boiler management system on every boiler. Steam Boiler control is not currently available. The Smith HeatNet control provides for optimized heating efficiency without the need for a “wall mount control”. Since the Smith modular control method is based on digital communications (Heat-Net), analog control signals are not required. Although the use of analog control signals is still supported (4-20mA control loops and 0-10vdc (20mA minimum) control voltages), a higher level of control precision, repeatability, and feedback is gained with digital communications control.

With the HeatNet control, optimized heating efficiency is accomplished by setting the Modulation Maximum (ModMax) setting to exploit the inverse efficiency curve. This value can be adjusted so that as each boiler is added, it operates at its maximum turndown. This allows the maximum number of boilers to operate at their lowest inputs, until all boilers are firing. Once all boilers are firing, full range modulation control is allowed. An outdoor reset function is also provided to assist in the optimized heating efficiency of the Smith boilers.

The Smith boiler with the HeatNet control, can be operated in multiple ways:

A. As a stand-alone boiler. B. A boiler in a Boiler Network using the HeatNet (H-

Net ™) protocol.

C. A member boiler controlled by a boiler management

system with multiple input control methods.

The primary purpose of the control is to maintain the boiler water temperature at the supply or the header sensor using a target setpoint. While performing this task, the control also monitors dedicated external limits in a limit string and provides an orderly shutdown and fault indication in the event of a tripped limit. The monitored limits include a HIGH LIMIT AQUASTAT, LOW WATER CUTOFF, GAS PRESSURE, FLOW, IGNITION CONTROL fault, GAS VALVE alarm, VARIABLE FREQUENCY DRIVE alarm, and other optional or user selectable limits.

The HIGH LIMIT circuit is independent of the

control and shuts down the ignition control and the boiler if the control board or other component of the boiler was to malfunction. The control will continue to function and report the fault, but its ability to control the boiler will end.

Each Smith boiler employing this control can function as either a master or a member. This allows one boiler (Master) to be in control of target temperature. The other boilers (Members) only respond to the commands issued by the Master. If using an external control, all boilers can be setup as members. The following will define the roles of master and member.

Master

A boiler becomes a master when a temperature sensor is connected to the J10 “SYS/DHW HEADER” terminals. The sensor is auto-detected.

The master senses and controls the common system header/loop water temperature using a system setpoint. It uses any boilers it finds (over the H-Net communications cable) to accomplish this. It can also monitor the Outside Air (OA) temperature to provide outdoor reset functionality. Only one

master is allowed in a system.

When operating as a master, the boiler provides a control method using a PID algorithm to regulate water temperature. This algorithm allows a single boiler (Master), or multiple (Master + Member) boilers.

Figure 1

The control algorithm is based upon a Heat Band, at the center of which is the setpoint. While below the Heat Band, boilers are staged on and modulated up until the Heat Band is entered. Once in the Heat Band, modulation is used to maintain setpoint. Boilers are shut down only when the top of the Heat Band is breached. Timers are also used to prevent short cycling.

While staging the boilers on, a modulation clamp ADVANCED SETUP:MOD MAX – LAST FIRE is used to hold the boilers at a lower fire rate until the last boiler is fired. Once the last boiler fires the modulation clamp is removed and all boilers are allowed to fire above this clamped percentage to 100%. This “boiler efficiency” clamp is defaulted to 70% and thus limits all of the boilers individual outputs to 70% until the last boiler fires. All running boilers modulate up and down together, always at the same modulation rate. As a general rule, this percentage should be no lower than twice the minimum turndown to minimize short cycling.

the system, the Master boiler employs an ADAPTIVE MODULATION algorithm to prevent over firing of the system. The Master communicates over the H-Net to view

Heat band

BOILERS

UPPER HEAT

BAND LIMIT

SETPOINT

LOWER HEAT

BAND LIMIT

WATER

TEMPERATURE

STAGED

OFF

Boilers Staged

Time

When additional boilers are needed to achieve setpoint in

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FEATURES & SPECIFICATIONS HeatNet Control REV 1.38-1

the exact status of each Member boiler. When a new boiler is added, the Master boiler adjusts the system modulation rate lower to compensate for the BTUs that will be introduced by the newly added boiler. This adjustment occurs when the newly added Member boiler enters its ON CALL state (default setting). This can be changed to PILOT when the new boiler is called using the menu: ADVANCED SETUP:ADAPTIVE MOD:DROP DOWN. Once the Main Valve (on the newly added boiler) is opened, and the DELAY RELEASE timer equals zero, the PID algorithm is allowed to control the system modulation. Setting the DELAY RELEASE timer will allow some “soak” time of the newly added boiler before releasing modulation control to the PID.

The ADAPTIVE MOD menus are disabled on a

Member boiler, but are still visible.

Member

If a “SYS/DHW HEADER” sensor is not connected to J10, a boiler always defaults to the role of Member.

The Member boiler can operate as part of a multi-boiler system or as a stand-alone unit.

In a multi-boiler system the Member typically receives its command signals from a designated Master-boiler. It is also capable of receiving inputs from an external control system. The boiler responds to these signals, to start/stop the burner, and/or to modulate the firing rate. The outlet water temperature is also monitored. If the outlet temperature approaches the operating limit temperature setpoint (adjustable), the boilers firing rate is limited and its modulation value is reduced to minimize short-cycling. If the operating limit is exceeded, or if an interlock trips, the boiler is shut down. When connected with a network cable, in a Master/Member role, the Members' status is interrogated by the Master boiler.

In a stand-alone installation the Member typically receives its command signals internally and operates based upon the outlet water temperature input and the established settings in the menu (Local Set-point) to start/stop the burner, and/or to modulate the firing rate. If the operating limit is exceeded, or if an interlock trips, the boiler is shut down. As in a multiboiler system, a stand-alone Member boiler is also capable of receiving inputs from an external control system.

When using the H-Net network cable in a Master/Member system, the system setpoint is sent from the Master as a digital signal, along with the modulation value to control firing rate. It also receives its command to start or stop over the H-Net cable. Also, the SYSTEM CLOCK only needs to be set on the MASTER. The Master will then set the time on all member boilers.

If not using the H-Net protocol (cable), an external control can send a 4-20ma signal along with a 4-20ma enable signal to control the firing rate or setpoint. The boiler may also be treated as a 2-stage boiler or an ON-OFF boiler using the dedicated T-inputs.

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FEATURES & SPECIFICATIONS HeatNet Control REV 1.38-1

Features & Specifications

1. Five levels of external control inputs, including

modulation and staging that provide application flexibility.

2. Digital Communications Control (analog 4-20ma and 0-

10vdc control supported, but not required).

a. Boiler to Boiler : HeatNet (H-Net)

b. Building Management System (MODBUS,

Optional BACnet or LonWorks) to Boiler

3. Distributed control using the HeatNet (H-Net) protocol

for up to 16 boilers. Eliminates the need for “wall mounted” controls.

4. Analog Control 4-20ma and 0-10vdc (20mA minimum

current) signals supported.

5. System/Boiler operating status text display

6. Interlock, Event, and System logging with a time

stamp.

7. Advanced PID algorithm optimized for the Smith-

Series boilers.

8. (5) Dedicated temperature sensor inputs for: Outside

Air Temperature, Supply (Boiler Outlet) Temperature, Return (Boiler Inlet) Temperature, Header (Common System Supply) Temperature, and a Stack sensor for monitoring stack temperature conditions

9. Automatically detects the optional temperature sensors

on power up.

10. Menu driven calibration and setup menus with a bright

(Adj.) 4 line Vacuum Fluorescent Display.

11. (8) Dedicated 120vac interlock monitors (selectable),

and 8 dedicated 120vac system monitors used for diagnostics and providing feedback of faults and system status.

12. Multiple circulator pump control modes.

13. Combustion Air Damper control with proof time,

support for a common combustion air damper.

14. USB/RS485 network plug-in to allow firmware updates

or custom configurations.

15. Optional BACnet or LonWorks interface.

16. Alarm Relay dry contacts, and Audible Alarm.

17. Runtime hours, and Cycles(based on Main Valve

Open).

18. Outdoor Air Reset with programmable setpoint and

ratio.

19. Time of Day clock to provide up to (4) night setback

temperatures.

20. Failsafe mode when a Building Management System is

controlling setpoint. If communications is lost, the boiler/system automatically transfers to local boiler setpoint control.

21. Rotation Methods(Lead-Lag): True Rotation (based on

boiler runtime)is default. First On First Off (FOFO), and Last On First Off (LOFO) is an optional programmable setting.

22. Programmable password protection to secure the

programmable settings.

23. Heat exchanger delta T limiting feature. If the

temperature across the heat exchanger is greater than 40F, a menu selection can set to one of (2) modes. (1.) The input rate is reduced to half of the called for rate. (2.) The boiler will shut down, but when the Delta temperature across the heat exchanger drops by 10 °F the boiler will restart.

24. Low inlet temperature warning if return water

temperature drops below 130°F.

25. Remote 4-20mA setpoint control using a mapped

setpoint range to the 4-20mA control signal.

26. Freeze Protection allowing automatic starting of

boiler(s) using (2) Failsafe modes.

27. Adaptive Modulation. When additional boilers are

called, the Master adjusts all boilers fire rates to compensate.

28. Mixed boiler types in a system.

29. Support for Domestic Hot Water (DHW) using a 10k

Sensor or a dry contact input from a tank thermostat.

30. Domestic Hot Water relay for use with a pump or

valve.

31. On-board power and socket for Protocessor

BACnet/LonWorks module.

32. HI/LO relay control option from connector J4

33. Stack temperature Warning at 550F and the fire rate

limited to ½ rate at 700F

34. Base Loading of (1) boiler.

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FEATURES & SPECIFICATIONS HeatNet Control REV 1.38-1

Specifications

Control Microprocessor based PID modulating control (NOT a safety limit )

Environment -40 F to 140 F, <90% RH non-condensing

Input Power 24 VAC, 500 ma

Relays System Pump, Damper, Circulator, Alarm, DHW Pump 8A 250 VAC resistive

K8 on J4.1 &.2 for Base Loading and Dual Fuel 1/4 Amp

AC Interlocks 24 VAC – 120 VAC input

Control Inputs AA, Heat Demand, 4-20ma Enable, OA override, T1-T2 (dry contact inputs)

4-20mA, 0-10 VDC (20mA source current)

Dimensions Board: 9” wide: 6” high : 2” deep, Enclosure: 11 ¾” wide: 10” high : 5” deep

Temperature Sensors NTC thermistor, 10K @ 77 F, ,+/- 1 F; 1k PT RTD

USB 1.0

RS485 MODBUS Modbus RTU

Boiler-to-Boiler HeatNet (H-Net)

Network Optional LonWorks, BACnet available bridge to MODBUS port

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FEATURES & SPECIFICATIONS HeatNet Control REV 1.38-1

Components & Accessories

Part Number Component

Smith-Series Control Board

02-4278 Graphics Display Board

02-3926 Temperature probe (bullet type, 1x.250 inch) ACI/10K-CP-BP

02-4283 Supply, Header, Return Sensors ACI 10k-CP-I-NW

02-4285 Sensor with well ACI CP-I-2.5”

02-4286 Sensor with well ACI CP-I-4”

02-4281 Strap-on sensor ACI 10k-CP-S

02-4280 Outside Air Sensor with Housing ACI 10k-CP-O

Installation & Operation Manual

40-5409 RJ45 Communications Cable Assembly, 25 feet

40-5411 Ribbon Cable Assembly (Display Control)

58-1833 10k ohm Calibration Resistor

40-5408 USB Cable Assembly, 6ft

60-5631 Terminal Block Screwdriver

Contact Factory MODBUS to BACnet bridge

Contact Factory MODBUS to LonWorks bridge

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SETUP & OPERATION HeatNet Control REV 1.38-1

Master

Members

SETUP & OPERATION

Basic Multi Boiler System Operation

For boiler system setup/installations please

refer to Refer to the 2008 ASHRAE Handbook, CH12 or later revision.

A basic multi boiler system typically uses boilers of the same size and type. With HeatNet, this includes (1) Master and (1-15) Member boilers. The boilers are connected together using an H-Net communications cable effectively creating (1) boiler. This allows the system heating BTUs to be distributed amongst all of the boilers. (See: Error!

Reference source not found., Error! Reference source not found., page Error! Bookmark not defined.). Error! Reference source not found., Error! Reference source not found., page Error! Bookmark not defined.).

Figure 2

A basic multi boiler system can be configured using the boiler menus to create custom systems/features. These features are best described in the section: Default Settings

& Menu Item Description, page 46. Along with these menu items are hardware support for many auxiliary functions.

Once the system has been properly setup (all default menu values used and HeatNet addresses assigned), the system is enabled by placing the REMOTE/LOCAL switch to the LOCAL position on the Master boiler. All Member boilers must have their respective switches in the REMOTE position. Once the Master boiler’s Heat Demand input (LOCAL switch) closes, the system is operational and will fire as many boilers as it needs to maintain the header water temperature’s setpoint.

When a boiler is to be fired in a multi boiler system (header water temperature is below the heating band), the Master checks the HeatNet boilers it has available. Then the Master checks if a Lead Boiler is to be used (LEAD BOILER > 0). The Master boiler then looks at which type of firing rotation it has selected: LOFO, FOFO, TRUE (runtime), or MIXED. In our example we will use the TRUE (runtime) rotation since it is the default.

Basic multiple boiler system

1 to 15 boilers total

The Master now checks all of the runtimes to determine which boiler has the least runtime based on the MIN RUNTIME setting in ADVANCED SETUP:FIRING MODE:. The MIN RUNTIME setting is the minimum runtime interval in hours that is used to compare boiler to boiler runtimes.

Once the boiler to fire has been determined, the Master sends the command over the H-Net cable to fire that boiler and resets the ADD BOILER delay timer to prepare for the next boiler to fire. If the header water temperature is still below the heating band and the ADD BOILER delay timer has counted down to 0, the process is repeated until the header water temperature enters the heating band.

When a boiler receives a command to fire it:

1. Enables the System Pump Relay and waits for the

System Flow Prove switch to make in the interlock string (J5B.1).

2. Next, the interlock string is checked for any other

tripped interlocks (J5A & J5B). Also, the High Limit, Ignition Control, Gas Valve Prove (Optional), and any hardware faults (sensors, etc…) are checked before continuing.

3. If all interlocks are good, and if the combustion air

damper is used, the K5 combustion air damper relay is enabled. The damper prove switch is then monitored for closure.

4. The local pump relay K6 is now energized and the

proof of flow is monitored for closure on J5B.7.

5. With all interlocks good, the boiler start relay K1

energizes and provides a signal to terminal 6 of the ignition control.

6. The ignition control then begins an ignition cycle by

first energizing its blower relay. The H-Net control then sets the blower VFD to the Pre-purge speed.

7. The ignition control then waits for the air switch to

close by monitoring its terminal 7.

8. Once the pre-purge time expires on the ignition control,

it closes its pilot valve relay causing the H-Net control to adjust the blower to the ignition speed and attempt to light the pilot.

9. If the pilot is successful, the ignition control energizes

its main gas valve relay and starts its trial for main flame (UV scanner).

10. Once the main flame is proven, the H-Net control holds

the fire rate at low fire for the MODULATION DELAY time period. After this time expires, the PID modulation is then allowed to modulate the boiler and places the boiler in the running state.

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SETUP & OPERATION HeatNet Control REV 1.38-1

As boilers are added to the system the ADVANCED SETUP:ADAPTIVE MOD:DROP DOWN menu determines when the modulation rate drops down to compensate for the newly added BTUs. For the drop down to be active one boiler needs to be running when a new boiler is added (see: Introduction: Smith HeatNet Control: Master).

If all boilers are firing, the modulation rate is allowed to go to 100%. If all boilers are not firing, the modulation is limited to the MOD-MAX clamp value. The MODMAX clamp is used to keep the boilers running as efficiently as possible. The following Mixed Boiler System Operation: Selecting Mixed Boilers section outlines this with examples.

Once the header water temperature is in the band, only the modulation rate is used to achieve the target setpoint. The system will then maintain setpoint until the load demand increases or decreases.

As the load decreases, the header water temperature will start approaching the top of the band. The PID now lowers the modulation rate to the boilers while trying to keep the temperature within the heating band. If the system is now delivering too many heating BTUs, the water temperature will cross the top of the heating band.

When the header water temperature first exits the top of the heating band, the runtimes of the boilers are again checked for the one with the most runtime. The selected boiler will then turn off immediately and a shed boiler delay timer will be loaded with the SHED BOILER delay time. This time will need to expire before the next boiler will stop, but only if the header water temperature remains above the heating band. This timer is used to allow the header water temperature to settle back into the band when a boiler is stopped. When a boiler is stopped there is a fixed rate of BTUs (Min Fire) that will be removed (PID discontinuity to modulate from Min Fire to 0 BTUs on a boiler). The timer allows for this immediate large discontinuous loss of BTUs.

This cycle will continue until the call for heat is removed or the Warm Weather Shutdown feature is enabled.

Mixed Boiler Types Using Priority Sets

Using the Basic Multi Boiler System Operation, a MIXED boiler priority method may be added to control condensing, non-condensing, base load, or other boiler SETs in a system together. These sets compose a system which provides for optimal performance and economy. A boiler set can be constructed by simply setting the firing priority on each boiler (to be in a set) at the same priority. Setting all (example) condensing boilers to the highest

priority of 1, and then setting all (example) non-condensing boilers to a priority of 2, will create (2) sets of boilers, one condensing and the other non-condensing. Once this is done, the priority 1 set of condensing boilers will have a firing order that has a higher priority and is independent of the other non-condensing set with the lower priority. The boiler set with the highest priority can then be fired based on a conditional settings menu. The lower priority set will follow.

Mixed Boiler System Operation

Starting Boilers:

When a boiler is to be fired (water temp is below the heating band), the Master checks the HeatNet boilers it has available. The Master boiler then looks at which boilers are returning priority firing status (set on a boiler in: (ADVANCED SETUP:SYSTEM:BOILER TYPE:PRIORITY : 1). If the Start condition for the Priority 1set is met (ADVANCED SETUP:FIRING MODE: MODE: MIXED:SET FIRST (example), the Master or Member boiler that is configured as PRIORITY 1, with the lowest runtime, will be fired FIRST (example).

As long as the start condition for Priority 1 is met, all boilers in the PRIORITY 1 set will fire based on runtime. Once all boilers in the PRIORITY 1 set have fired, the PRIORITY 2 set of boilers will fire based on runtime.

If the Start condition changes and/or is not met (such as with: OA T or RET temp), the PRIORITY 2 set of boilers will fire first/next based on runtime. This has the effect of flipping the priority of the sets.

Stopping Boilers:

When a boiler is to be stopped (water temp is above the heating band), the Master checks the HeatNet boilers it has available. The Master boiler then looks at which boilers are returning priority firing status (set on a boiler in: (ADVANCED SETUP:FIRING MODE: MODE: MIXED:SET LAST(example) If the Stop condition for Priority 1 is met, the Master or Member boiler that is configured as PRIORITY 1 with the highest runtime will be stopped LAST (example). As long as the stop condition and SHED DELAY time are met, all remaining PRIORITY 1 set of boilers will stop based on runtime. If the Stop condition changes and/or is not met (such as with: OA T or RET temp), the PRIORITY 2 set of boilers will stop first/next based on their highest runtime.

A boiler’s firing priority can be designated as such in: “ADVANCED SETUP:SYSTEM:BOILER TYPE:FIRING PRIORITY : 1” menu on each boiler. A priority of ‘1’ is the highest priority, a ‘2 the lowest (default is always 2).

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OPTIONAL FEATURES HeatNet Control REV 1.38-1

S E T : O A T < 1 5 ° F

Figure 3

FIRING MODE menu

(master boiler only)

BOILER TYPE menu (all boilers in set)

Mixed Boilers: Example: Condensing/Non-Condensing

Master

PRIORITY 1

Condensing (Set)

>MODE MIXE D MIN R UN TI ME: 10HR s MIN O FF TIME: 0s PREDICT S TART: YES

>FIRING PR IORITY :1 BTU I N 2000,000 CONDENSING YES MASS MEDIUM

Non-Condensing (Set)

BOILER TYPE menu (all boilers in set)

PRIORITY 2

>FIRING PR IORITY :2 BTU I N 2000,000 CONDENSING NO OIL D IR EC T FIR E X XX

In the example Mixed Boilers: Condensing/NonCondensing., condensing boilers and non-condensing

boilers are used, but other combinations may also be used. Another example could use (2) small boilers and set them to Priority 1 and then use (3) larger boilers and set them to Priority 2. Using these priority settings (with the conditions menu), the small boilers can run first during the shoulder months (Spring and Fall) and the larger boilers can fire last during the colder Winter season (base loading set).

Before the MIXED method can be used, the firing mode on the Master boiler must be set to MIXED. ADVANCED SETUP:FIRING MODE: MODE: MIXED. Pressing the SELECT key when the cursor is pointing to MIXED will enter the conditions menu. The START and STOP conditions for starting and stopping the priority boiler set may be configured here. Temperatures are adjustable.

S T A R T P R I O R I T Y 1 > S E T : F I R S T S T O P P R I O R I T Y 1

Start/Stop Priority Conditions

The following is an example using mixed condensing and non condensing boilers:

FIRE FIRST

Condensing boilers may be configured to fire first (set to PRIORITY 1) when:

1. The Return water temperature is below 140F and

condensing occurs. (The Master’s return water sensor would need to be moved to the header return.)

2. The Outside Air Temperature is above a setpoint

determined by the system configuration. This setpoint ensures that the more efficient condensing boilers run first during shoulder months (Spring and Fall) when minimal heating is required. Below this setpoint, larger boilers should be brought on first to “base load” the system.

3. Greater efficiency is required.

Once the conditions menu has been entered, the firing order and stop order of the priority 1 boiler set can be selected based on up to (3) conditions in the conditional settings menu. All conditional settings apply to the priority 1 boiler set. When the conditional settings do not apply to the priority 1 set, the conditional settings will apply to the priority 2 boiler set.

Page 11

STOP FIRST

Condensing boilers may be configured to stop first (set to PRIORITY 1) when:

1. The Return water temperature is above 140F and

condensing is minimized, thus leaving the larger lower cost boilers running to carry the load.

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SETUP & OPERATION HeatNet Control REV 1.38-1

S E T :

L A S T

2. The Outside Air Temperature is below an adjustable

setpoint determined by the system configuration. This setpoint ensures that the larger non-condensing boilers run during the coldest months when maximum heating is required. Above this setpoint smaller condensing boilers should be brought on first to run the system as efficiently as possible.

3. Maximum heating is required

START PRIORITY 1 SET SELECTIONS

(Always the lowest runtime first):

The condensing boiler set (Priority 1) has a

higher Priority to fire when one of these conditions is met. Values are adjustable.

FIRST: The condensing boilers (Priority 1) are always started FIRST

OA T > 15F: The condensing boilers (Priority 1) are started when the OA temperature is greater than the Mixed Boiler Outdoor Air Temperature setting.

RET < 140F: The condensing boilers (Priority 1) are started when the Return water temperature is less than the Mixed Boiler Return temperature setting (This may not applicable in most configurations since the local return temperature on the Master is used to provide a difference temperature across the heat exchanger. However, the return temperature sensor may be moved on the Master to provide system return temp if the difference temp is not required).

STOP PRIORITY 1 SET SELECTIONS

(Always the highest runtime first):

The condensing boiler set (Priority 1) has a

higher Priority to stop when one of these conditions are met. Values are adjustable.

LAST: The condensing boilers (Priority 1) are always stopped LAST.

OA T < 15F: The condensing boilers (Priority 1) are stopped first when the OA temperature is less than Mixed Boiler Outdoor Air Temperature.

RET > 140F: The condensing boilers (Priority 1) are stopped first when the Return water temperature is greater than the Mixed Boiler Return temperature. (This may not applicable in most configurations since the local return temperature on the Master is used to provide a difference temperature across the heat exchanger. However, the return temperature sensor may be moved on the Master to provide system return temp if the difference temp is not required)

Start/Stop settings

Any combination of Start Conditions and Stop Conditions can be used to optimize the mixing of condensing (Priority

1) and non-condensing boilers (Priority 2) for best performance/economy.

The default settings for the start and stop conditions of the condensing set are:

S T A R T P R I O R I T Y 1 > S E T : F I R S T S T O P P R I O R I T Y 1

The default start setting always starts the condensing boilers (Priority 1 example) first, except for the lead boiler setting. The lead boiler will always start first if enabled, unless there is a boiler already running (this includes a Member boiler in LOCAL). The default stop condition setting always stops the condensing boilers (Priority 1) last.

If prolonging the life of the heat exchanger(s) on noncondensing boilers is very important, consider starting the condensing boilers (KN series) when the return water temperature is below 140F.

The return water temperature sensor would

need to be moved from the Master’s return inlet to the system return. The EXCHGR

DELTA may need to be adjusted in SETUP:AUX FUNCTIONS:HEAT EXCHANGER to prevent the Master from

going to ½ input when a high DELTA T is reached.

This method would lead to the non-condensing boilers carrying the load when the system temperature stabilizes above 140F, since non-condensing boilers will start first with the Return water temperature is > 140F. The condensing boilers can then be stopped first when the RET water temperature is above the 140F. Remember, any combination of the Start and Stop conditions may be applied for best performance and economy in the system.

Base load boilers can also be mixed in the same way as condensing and non-condensing boilers. The base load boiler(s) can be prioritized in one set (example, Priority

2) and non-base load boilers (Priority 1). The non-base load boilers can then be set to fire first and once they are all firing, the base load boiler would fire.

To minimize the cycling of a large base load boiler, consider using the stop condition. Change it to the OA T < 15F (Outside Air Temperature) condition. This setting may be used to stop the priority 1 boiler set when the OA T drops below the OA T setpoint, thus leaving the large base loaded boiler on and shutting off

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SETUP & OPERATION HeatNet Control REV 1.38-1

System

Effective

MOD

the condensing boilers first. This is also true when using the OA T setting to start the priority 1 boiler set when the OA T is above the start setpoint. To use temperatures as start and stop conditions, the system design temperatures must be known.

Selecting Mixed Boilers

There are a few factors to consider when choosing which type of boilers to use in a mixed system. These factors need to be considered when boilers are added or shed. When BTUs are introduced into the system by adding boilers, the amount of introduced BTUs should be smooth (linear). If these factors are not considered, discontinuity in BTUs may occur when boilers are added and as a result, short cycling will occur.

1. Turndown: This is the ratio of minimum fire rate

to maximum fire rate: Example: a 20% minimum modulation = 5:1 turndown (100%mod / 20% mod). A (1) million BTU boiler = 200,000 BTUs minimum input.

2. MOD MAX CLAMP: This value determines the

maximum modulation % at which the boilers will fire to until all available boilers are firing.

3. Total System BTUs.

4. Desired Effective Turndown. This is the lowest

firing rate of the system relative to the maximum firing rate of the system. The larger the value, the lower the BTUs that can be delivered to a light load.

5. Piping.

In order to achieve the high effective

turndown, smaller boilers are required (plumbing considerations need to be considered here due to differing flow/volume characteristics through the large and small boilers).

Example Systems:

Figure 4

MMBTU

3.5 9:1 70%

13.8 12:1 70%

23.1 15:1 70%

With the traditional Non-Mixed boiler system, the effective turndown increases by the turndown ratio for every boiler added. The min fire rate is equal to the minimum BTUs that can be delivered to the system.

Number of boilers * Turndown Ratio = Effective System Turndown: 5 * 3:1 = 15:1.

With the mixed boiler system, a lower minimum fire rate/BTU can be delivered to the system by using small boilers with larger boilers. Condensing and NonCondensing of different sizes can also be mixed as illustrated in Figure 5 - Mixed Boiler System chart.

Non-Mixed Boiler System

Turndown

MAX

MB/MW 4:1

28A-W-5, 28A-W-5,

28A-W-5

28A-W-11, 28A-W-11,

28A-W-11, 28A-W-11 28A-W-18, 28A-W-18, 28A-W-18, 28A-W-18,

28A-W-18

Mixed System:

High System Turndown Condensing/Non-Condensing

The following examples are of mixed boiler systems with high effective system turndown, fault tolerance, and condensing/non-condensing applications. When boiler types are the same, the system turndown is limited to the boiler’s min input and fault tolerance is always present. When the system has mixed boiler types, consideration needs to be taken on what types can be mixed properly to achieve a high system turndown and provide some fault tolerance. Fault tolerance allows for one boiler in the Priority 1 system to fail and any boiler(s) in the Priority 2 system to fail and still provide near linear (continuity) BTU response when adding boilers. This is illustrated in the following examples using the Boiler System Response graphs.

The Smith Mixed Boiler System (examples) is advantageous in providing low BTU input for light loads and high BTUs for heavy loads. The effective system turndown minimizes short cycling when light loads are present by assigning smaller boilers to Priority 1, running them first, and then stopping them last.

Figure 5

System

MMBTU

3.5 29:1

6.46 32:1

11.12 28:1

13.25 33:1

Mixed Boiler System

Effective

Turndown

MAX%

*54

86%

*47

62%

*57

87%

*67

99%

Priority 1

5:1

KN6, KN6

KN20, KN20

Priority 2

3:1

28A-W-5, 28A-W-5

28A-W-9, 28A-W-9

28A-W-14, 28A-W-14

28A-W-18, 28A-W-18

* The MOD MAX% column has (2) numbers for the MOD MAX %. The first # does not allow for redundancy while the second # does. Redundancy provides for continuity in BTUs when a new priority boiler is added and one is offline.

If one of the priority boilers goes offline and redundancy is not provided for, short cycling will occur due to discontinuity in BTUs. The second # allows for redundancy so one of the priority boilers can be taken offline with no discontinuity. This will be explained more in the following examples.

When selecting the Priority 1 boiler(s) for a high effective system turndown, the BTU Min Input is selected first. (See:

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SETUP & OPERATION HeatNet Control REV 1.38-1

Min Input

Mod Max

KN2 KN4 KN6 KN10

KN20

KN30

Max

Min Input

Mod Max

KN BOILER BTU CHART ). Next, the MOD-MAX value of this Priority 1 boiler needs to be greater than:

Mod MAX % =

(Priority 1 ‘s Min Input + Priority 2 ‘s Min Input)

Max Input of the Priority 1 boiler

The reason for this is keep the continuity of BTUs linear without a BTU bump (discontinuity) when boilers are added or shed. This is illustrated in the Boiler System Response 2 graph.

If redundancy is not required, the min inputs of the Priority 1 boilers may be summed to lower the Mod Max % value so smaller priority 1 boilers can be used. The sum of the min inputs would then need to be divided by the sum of the Max Input of the Priority 1 boilers. The effect of this would create a higher turndown. See: EXCEPTION NOTES:

Mod MAX % =

( ((Priority 1 Min) * (#Priority 1’s)) + Priority 2 Min)

Max Input of Priority 1 boiler * (#Priority 1’s)

Example: (2) KN6s, (2) 28A-W-5s Redundancy: (120 + 385)/600 = 84% No Redundancy: (120 * 2) + 385)/(600*2) =52%

EXCEPTION NOTES:

1. Mixing more than two different size/type boilers

becomes more complex than the scope of this manual and is not recommended.

2. If using more than one Priority 1 boiler and the

calculated value is <

Priority 1Min * 2

Priority 1 Max Input

Use this result Plus note 3 vakue as the MOD MAX %.

3. Always add a few % (3-5%) to the calculated MOD

MAX % value to allow a guard band (tolerance).

4. If boilers are of different sizes, try to use larger priority

2 boilers.

5. If the calculated Mod MAX % value is greater than

99%, the combination can not be used since short cycling will occur.

Figure 6

Max Input

Smith Boiler Btu Chart (MBH)

3:1

80%

70%

60%

50%

28A-W-5 28A-W-9 28A-W-14 28A-W-18

1156 2232 3563 4629

385 744 1187 1543

925 1785 2850 3703

809 1562 2494 3240

693 1338 2137 2777

578 1116 1781 2314

Figure 7

Input

5:1

80%

70%

60%

50%

KN Boiler Btu Chart (MBH)

200 400 600 1000 2000 3000

40 80 120 200 400 600

160 320 480 800 1600 2400

140 280 420 700 1400 2100

120 240 360 600 1200 1800

100 200 300 500 1000 1500

Once the Priority 1 and Priority 2 boilers are selected, they can be multiplied in each priority set to achieve the desired system design BTUs. If the # of boilers becomes a large number, a Priority 1 boiler with a higher Min Input may need to be selected.

While considering the MOD-MAX value, the lower the MOD-MAX the greater the combustion efficiency since it effectively limits the input rate. The Typical Efficiency of Non-Condensing Boilers chart can help illustrate how the MOD-MAX value can affect the efficiency by limiting the input until all boilers have fired. Non-condensing boiler efficiency is relatively flat compared with condensing as illustrated in the Typical Efficiency of Condensing Boiler graph.

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SETUP & OPERATION HeatNet Control REV 1.38-1

Figure 8

Typical efficiency of non -condensing boilers

Figure 8

(GAMA BTS2000 method)

In the first row of Figure 5 – The Mixed Boiler System table KN6s are set as Priority 1 and 28A-W-5’s set as Priority 2. With a MOD MAX of 54%, each KN6 can run to 324M (648M total) before a 28A-W-5 is called ON (Add Delay timer set long enough). Once both KN6s are running and the 28A-W-5 is called on and running, all (3) boilers will drop to a total of the ~625M BTUs: The sum of the KN6, KN6, and 28A-W-5. About 22% KN modulation: (.22* 600M) + (.22* 600M) + (.33* 1.156MM) or: ~132M +~132M + ~385M = ~650M and operate at higher combustion efficiencies. 22% is roughly between the top two lines on the Typical Efficiency of Condensing Boilers chart for the KN’s. The 33% is the minimum firing rate for the 28A-W-

Typical efficiency of condensing boilers

‘~’ is defined as approximate

Figure 9

Boiler System Response 1

(2) KN6’s, (2) 28A-W-5’s

Blr 1+2 (1200 MBTU)

1.00

0.90

0.80

0.70

0.60

0.50

0.40

0.30

0.20

0.10

0.00

0 1,000,000 2,000,000 3,000,000 4,000,000 5,000,000

System Load , Btu/Hr

Blr 1+2+3 (2356 MBTU)

Blr 1+2+3 +4 (3512 MBTU)

Figure 9 - Boiler System Response 1 chart illustrates how each boiler (in the example) is brought on and fires to 54%, drops to a lower fire rate and then adds the next boiler (vertical dashed lines). Once all boilers are firing, the modulation is released allowing all boilers to fire to 100%. So, for the first 1270 MBTH of load, the combustion efficiency is maximized by running the boilers from low to middle input rates.

Now if a (2) boiler system using (1) KN6 with (1) 28A-W-5 and MOD-MAX set to 54, the KN6 would fire to 324 MBTUs and wait for the 28A-W-5 (Figure 10 - Boiler System Response 2 graph). Once the 28A-W-5 fired, the modulation would drop down and the input rate would jump to 505 MBTUs, 385M (28A-W-5 @ 33%) + the 120M (KN6 @ 20%). The system load was looking for 324 BTUs, but there would be 181 MBTUs more than needed.

The PID algorithm would then compensate for the large discontinuity (over fire bump) in BTUs and the 28A-W-5 would shut off (short cycle). This discontinuity is observed in the graph below, (Figure 10 - Boiler System Response 2 graph) where the jump from the KN6 @54% to the firing of the 28A-W-5 is apparent.

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SETUP & OPERATION HeatNet Control REV 1.38-1

Figure 10

Boiler System Response 2

(1) KN6’s, (1) 28A-W-5’s, 54% Mod-Max

Blr 1+2 (1756 MBTU)

1.00

0.90

0.80

0.70

0.60

0.50

0.40

0.30

0.20

0.10

0.00

0 1,000,000 2,000,000 3,000,000 4,000,000 5,000,000

System Load , Btu/Hr

To correct this would require the KN6 to set the MODMAX to roughly 85% (Boiler System Response 3) in order to have a linear BTU transfer when the 28A-W-5 is added (fired).

Figure 11

(1) KN6’s, (1) 28A-W-5’s, 85% Mod-Max

Boiler System Response 3

Blr 1+2 (1756 MBTU)

1.00

0.90

0.80

0.70

0.60

0.50

0.40

0.30

0.20

0.10

0.00

0 1,000,000 2,000,000 3,000,000 4,000,000 5,000,000

System Load , Btu/Hr

A system employing redundancy, where (1) Priority 1 is allowed to be taken offline is shown in the Boiler System Response 4 chart. The example system uses (2) KN6s and (2) 28A-W-5s. Two of the KN6s are treated as one when adding the min inputs of the Priority 1 set.

Figure 12

Boiler System Response 4

(2) KN6’s, (2) 28A-W-5’s, 85% Mod-Max

Blr 1+2 (1200 MBTU)

1.00

0.90

0.80

0.70

0.60

0.50

0.40

0.30

0.20

0.10

0.00

0 1,000,000 2,000,000 3,000,000 4,000,000 5,000,000

System Load , Btu/Hr

Blr 1+2+3 (2356 MBTU)

Blr 1+2+3 +4 (3512 MBTU)

The mixed system may also have boilers with condensing and non-condensing types as has been illustrated. The reason for creating a mixed system is primarily to control the system cost.

In summary, the system should be tuned using the boiler selection charts and the MOD-MAX value so that boilers are brought on and fired in their respective efficiency curve while maintaining continuity in BTUs. Since selecting the Priority 1 boiler is integral to the fault tolerance of the system, it is important to note any discontinuities in BTUs if a Priority 1 boiler fails when multiple Priority 1 boilers are used.

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SETUP & OPERATION HeatNet Control REV 1.38-1

Master

Base Loading, Relay Control

The control has the ability to control (1) base load boiler using the K8 Relay contacts on J4 terminals 1 & 2. In order to connect to this plug, (2) wires are required and connected to J4. Base Loading via relay requires these (2) flying leads. These (2) wires then make up the Normally Open contacts. The solid state relay K8, with contact connections on J4.1 & J4.2 has a rating of: 0.1 to 1 Amp.

If the base load boiler is of the modulating type, a 0-10VDC signal is also provided on J4 pins 4- and 7+. Two additional wires will need to be added to the J4 pins at 4- & 7+. Pin 7 is the + output of the 0-10VDC transmitter, and pin 4 is the – output. This modulating control signal is used to modulate the base load boiler along with the HeatNet boilers in parallel. The ADAPTIVE MOD does not function in lowering the modulation rate when the base load boiler is added. The PID will adapt to the newly fired base load boiler and lower its modulation rate when the increase in water temperature is observed.

Figure 13

BASE LOADING menu

(master boiler only)

SYSTEM menu ( )master boiler only

Enable the base load feature by setting

1. ADVANCED SETUP:SYSTEM:OPTION to BASE

LOAD. This sets the OPTION Relay to be used as

control for a Base Load Boiler.

2. The ADVANCED SETUP:BASE LOAD BOILERS:

BASE LOAD BOILERS: to 1. Currently only allows (1) base load boiler.

3. The START & STOP qualifier condition to the method

discussed below.

Base loading with Smith Boilers

HeatNet Enabled 28A

>BASE LOAD BOILERS:1 START>MOD 95 STOP FIRST DELAY TIME 10mins

>BOILER TYPE LOAD FIRMWARE OPTION: BASE LOAD

Base load

Non - HeatNet

4. The DELAY TIME to the amount of time required after

the start qualifier condition has been met to start the boiler.

If a MINIMUM OFF time of the Base Load boiler is needed, the Base Load boiler will share the MIN OFF TIME of the boiler controlling it. If the base load boiler was running and shuts off, the MIN OFF TIME will need to expire before the boiler can start again. Once this time expires, the DELAY TIME also needs to expire to start the boiler. This will help in minimizing short cycle conditions and can be set at: ADVANCED SETUP:FIRING MODE: MODE:MIN OFF TIME.

Preferred Example Base Load:

A modulating base load boiler that can accept a 0-10VDC control signal such as the Smith 28 series is preferred. A 135 ohm input for the base load boiler will need a converter from 0-10VDC to 135 ohm if using KNs as the primary HeatNet boiler. The Smith HeatNet control has the 135 ohm feature built in.

Using the Smith HeatNet control on one Smith series boiler can allow a second Smith series boiler or other boiler type to be controlled using the base load feature.

http://www.Smithboiler.com/

If the base load boiler is not of the modulating type, stopping the Base Load boiler will require that the size of the Base Load boiler in BTUs is known relative to the HeatNet boilers. Boiler selection is ideally; having more total BTUs in the HeatNet boilers than total BTUs of the Base Load boiler. This will prevent short cycling. Example: (4) 2 million BTU HeatNet boilers = 8 million BTUs and (1) 6 million BTU Base Load boiler.

When all (4) HeatNet boilers are running @ 99%, the Base Load boiler is called on (demand is approx. 8 million BTUs). As the Base load boiler comes on it introduces 6 million BTUs and the HeatNet boilers modulate down to 25% for a total output of 2 million BTUs and running at high efficiency. The HeatNet boilers can now modulate to the load from 1.6 million BTUs (20% mod) to another 8 million BTUs.

Not Preferred Example Base Load:

Example of having a larger Base Load boiler that is not of the modulating type: If there is a 6 Million BTU Base Load boiler running with (3) 2 million BTU HeatNet boilers, a short cycling situation will arise when the (3) 2 million BTU boilers are running @ 99% and the Base Load boiler is called on. At this point there is a need for approximately 6 million BTUs. The (3) smaller boilers will then modulate down to low fire. At this point, the (3) smaller boilers need to shut off or the Base load boiler needs to shut off. There is no overlap. A selection for stopping the boiler now needs to be determined. Setting the Stop

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SETUP & OPERATION HeatNet Control REV 1.38-1

qualifier; Modulation to 40% or a low fire rate will shut the Base Load boiler off and allow the (3) smaller boilers to modulate up again (short cycle of the Base Load boiler; Use the Delay Timer and Min OFF timer). The Stop qualifier; OA T > xxF may also be used if the system design temperature is known. Then let the Base Load boiler cycle

Figure 14

Base Load Relay Wiring

1. First ensure that the ADVANCED SETUP:SYSTEM:OPTION: is set to BASE LOAD. The Base Load Relay (K8) will not be enabled/used unless this is selected.

2. Now, The ADVANCED SETUP:BASE LOAD:BASE LOAD BOILERS: must be set to 1.

3. When the START condition in the BASE LOAD BOILERS menu is met, the K8 relay will close. But, only when the DELAY TIME under the BASE LOAD BOILERS menu expires.

24 VAC

off its limits, whether a 2 stage, Hi/Lo, or modulating boiler. The default setting is for the Base Load boiler to stop first once the water temperature exceeds the top of the heating band.

Base Load RIB Relay

Enable Input on

Base Load Boiler

24 VAC Return, or

Chassis Ground

Base Load Relay

Page 18

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OPTIONAL FEATURES HeatNet Control REV 1.38-1

Setting up base loading

The base load boiler is controlled using a set of contacts to enable it (location J4). Enabling/Disabling this relay contact can be done using any combination of (3) qualifiers to start the boiler and (4) to stop the boiler. These qualifiers are:

1. Modulation %:

a. START menu item: The relay contact will close

when the MOD % from the Master boiler exceeds this value. ADVANCE SETUP:BASE LOADING:

START>MOD

STOP menu item

when the MOD % from the Master boiler falls below this value.

LOADING: STOP<MOD

If the START>MOD value is set to a value

higher than the ADVANCED SETUP:MOD- MAX: all boilers will be firing before this modulation rate is reached. This will ensure that all available boilers are firing before the base load boiler relay is enabled.

c. Setting the : STOP<MOD to a % value slightly above

the min fire rate % of the system will ensure that the base load boiler will stop before the first condensing boiler stops. This is due to the Modulation rate being close to the min modulation rate before the water temperature exceeds the top of the heating band.

2. Outside Air Temperature:

a. START menu item: The relay contact will close to

enable the boiler when the OA T read from the Outside Air Temperature sensor (if Equipped) falls below this temperature. ADVANCE SETUP:BASE

LOADING: START< OA T

b. STOP menu item: The relay contact will open to

disable the boiler when the OA T read from the Outside Air Temperature sensor (if equipped) rises above this value. ADVANCE SETUP:BASE

LOADING: STOP> OA T

: The relay contact will open

ADVANCE SETUP:BASE

3. Return Water Temperature

START menu item

to enable the boiler when the RET read from the Return Water Temperature sensor (if Equipped) falls below this temperature.

SETUP:BASE LOADING: START> RET

STOP menu item

to disable the boiler when the RET temperature read from the Return Water Temperature sensor (if Equipped) rises above this temperature.

LOADING: STOP< RET

FIRST

STOP menu item

to disable the boiler when the temperature exceeds the heating band. This gives the result of stopping the Base Load boiler First. Default setting.

: The relay contact will close

ADVANCE

: The relay contact will open

ADVANCE SETUP:BASE

: The relay contact will open

Delay Time

The DELAY TIME is also included to hold off starting the boiler until the delay time is met. Once the start condition qualifier term is met, the DELAY TIME will start counting down. When the time expires, the base load relay contacts will close. ADVANCE SETUP:BASE LOADING:DELAY TIME. It is adjustable in a range of: 0 to 60 minutes.

Base Load Failsafe

If there are no boilers available to fire (offline or faulted) and there are no boilers in local override, and there is a call for heat, The J4 Base Load relay will close. If a boiler becomes available and needs to fire, the Base Load boiler will remain firing until the temperature exceeds the band. This is provided to keep the system from entering a no heat situation.

If the OA T qualifier is used as the Start and

Stop qualifier, ensure that there is at least a few degrees difference for hysteresis.

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OPTIONAL FEATURES HeatNet Control REV 1.38-1

Heating Control Methods

An overview of the (5) methods for controlling the Smith series boiler are presented here. They are outlined in more detail at the end of this section. See Error! Reference source

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Heating Method 1

The first method is to use the Smith Series boiler in its standalone modulating method. This method uses a PID algorithm to maintain a setpoint and is enabled using the HEAT DEMAND input. Closing a relay contact or switch across the HEAT DEMAND input will cause the Master boiler to control all member boilers using H-Net.

A member boiler may also be controlled by the HEAT DEMAND input (LOCAL mode). The member boiler will then ignore commands from the Master and maintain its LOCAL SETPOINT at the supply sensor.

Heating Method 2

The second method is to view the Smith boiler as two separate boilers or as a HIGH/LOW boiler using T1 & T2.

Heating Method 3

The third method is to allow a remote 4-20 ma or 0-10 VDC signal to control the firing rate (modulation) of the boiler using the 4-20ma input, along with the 4-20ma REMOTE ENABLE input.

Short cycling may occur when a firing rate is

sent to a member boiler that would cause the supply temperature to rise high enough to trip the operating limit (low flow rate). After the supply temperature falls, the boiler would restart and the process may continue. A member boiler would use its supply (outlet) sensor to protect itself from short cycling by limiting the firing rate coming from the Master. This occurs in the event that the member’s supply temperature increases above the (OPERATE LIMIT- OPERATE LIMIT BAND).

Operating Limit

When the master boiler or an external control input is used to control a member boiler (i.e. AA, T1-T2, 4-20ma, H-Net), a software operating limit on the member boiler will be used to limit the maximum output of the member boiler. This operating limit can be adjusted in the SETUP:SETPOINTS:OPERATING LIMIT.

There is also an associated operating limit band that must be set in conjunction with the operating limit to help prevent this LIMIT from being reached. Its purpose, is to limit the output of the boiler as it approaches the operating limit. If the band is set to 10 degrees, then for every degree that it approaches the operating limit, the maximum output will be lessened by 10%. With a band of 20 degrees, for every degree that it approaches the band, the maximum output will be lessened by 5%. You can think of this operating limit as a smart aquastat which prevents the High Limit from tripping. This method minimizes boiler short cycling when using external inputs. The minimum setting is 1 degree and effectively turns the limit band OFF. The default setting is 20F.

Heating Method 4

The fourth method turns the boiler ON and OFF @ 100% modulation using the AA terminal.

Heating Method 5

The fifth method uses an RS485 digital communications cable with the MODBUS protocol. The boiler is controlled by writing and reading registers using MODBUS commands. A bridge module may also be used to convert BACnet or LonWorks protocols to MODBUS.

Page 20

Input Priorities

The Smith-Series control inputs are prioritized so that multiple levels of external control can be employed at the same time. This means that if we are firing the boiler with a low Priority input and a higher Priority input is called for, the boiler will now fire at the higher Priority input. When the high Priority input is removed, the boiler will revert back to the lower Priority input that is still being called.

Priority 1

The AA terminal has absolute control, and if used, will always fire the boiler at 100% output, regardless of any other input. The 4-20mA input may be raised to this Priority using ADVANCED SETUP: 4-20mA INPUT:PRIORITY.

Priority 2

The HEAT DEMAND input is the next, and provides the means to operate the boiler in LOCAL MODE when an external control is not present, has failed, or needs to be

Page 21

OPTIONAL FEATURES HeatNet Control REV 1.38-1

enabled or disabled. A member can override the H-Net commands using this input.

Priority 3

If a HeatNet (H-Net) Network cable is connected between boilers, and one is configured as a MASTER (requires HEADER sensor), then the MEMBER boilers will be controlled over the network by the MASTER.

Priority 4

The 4-20ma/0-10VDC input in tandem with the 4-20ma REMOTE ENABLE input is next. Any signal over 4.02ma or

2.01VDC will start and operate the boiler if the REMOTE ENABLE is closed.

Priority 5

The lowest Priority is using the boiler as (2) stages HIGH/LOW. These are the T1 and T2 inputs.

Each of these control methods will now be explained in more detail:

Heating Method 1 HEAT DEMAND

Closing a relay contact, switch, or jumper across the HEAT DEMAND input will enable this method. This method allows operation as a setpoint control. As a setpoint control, the Master (defined by having a common system supply header sensor), on the H-Net network can command the boiler fire rate of all Member boilers. The Master can call as many boilers that it has available (boilers are auto-detected over the H-Net cable by the Master) to meet its SYSTEM SETPOINT. The H-Net cable must be connected and will cause the amber light on the communications board to flash. The amber light indicates an H-Net master is broadcasting control information and a system heartbeat.

The AA terminal, the FAILSAFE mode active, 4-20ma at PRIORITY:HIGHEST, and the HEAT DEMAND input (LOCAL) on a Member, are the only inputs that will override the H-Net control.

Figure 15

Master Boiler

The MASTER boiler controls the system using a PID algorithm. Once the boiler is started, a PID algorithm is used to produce a modulation percentage value from 0-100%. This percentage is converted to a PWM, (P)ulse (W)idth

Heat Demand Input

MASTER: Close contact to control all boilers and run at system setpoint. MEMBER: Close to run at LOCAL setpoint

(M)odulation or 0-10VDC signal by each boiler. The temperature of the water is maintained by sending this signal to the Mod Motor, which in turn controls the damper position and fuel rate. providing the firing rate control.

Member boiler(s)

A Member (lacking a common system supply header sensor) boiler may also be controlled by the HEAT DEMAND input (LOCAL mode). The member boiler will then ignore commands from the Master and maintain its own LOCAL SETPOINT at its supply sensor. This can be viewed as a manual override on a member boiler. Be sure to observe the proper use of a Common System Damper (See: AUXILIARY FUNCTION OPTIONS section) and any system pumps or system common interlocks.

Features of the HEAT DEMAND input include:

1. The control is designed to predict when to start and

stop the boiler and keep the setpoint in, or as close to the control band as possible. If PREDICTIVE START is enabled, the boiler may start when it is in the band and not below it. This will help to maintain a more accurate temperature relative to the setpoint. See also: ADVANCED SETUP:FIRING MODE:PRDICTIVE START: to disable this feature.

2. The control can also use the Outdoor Reset feature.

This feature allows the setpoint to be changed automatically based on the outside air temperature. If this feature is used, the control input: OR OVR (OUTDOOR RESET OVERRIDE), can be used to override the Outdoor Reset feature and run from the local setpoint. A contact closure on the ‘AA’ input can also override this method.

3. The Setpoint can be controlled remotely using the 4-

20ma setpoint control function.. This function translates a 4-20ma control signal to a setpoint mapped between 50F and 220F. These (2) temperatures are adjustable to provide a setpoint range. The minimum start current is also adjustable between 3.71 and 5ma. The setpoint control feature is used in conjunction with the REMOTE ENABLE input on J12A. This feature is enabled in the SETPOINTS menu as:

SETPT SOURCE 4-20ma

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CONTROL METHODS HeatNet Control REV 1.38-1

Heating Method 2 STAGE Control T1-T2

1. Closing only one of these contacts tells the boiler to

operate at MINIMUM FIRE.

2. Closing the other contact will fire the boiler at

MAXIMUM output (the same rate as closing the AA input).

Figure 16

The AA, HEAT DEMAND (LOCAL) input, the H-Net, the 420ma input will all override the stage control inputs

Stage Control Input

T1 T2

The maximum output of the boiler is based on

the MAX VFD setting in the calibration mode and not the nameplate rating.

Method 2: LOW FIRE, HIGH FIRE Close contacts here

Heating Method 3 4-20ma Control

Placing a current source between the + and – 4-20ma inputs will allow remote control of the boilers firing rate. An adjustable starting milliamp current signal here will start and then fire the boiler at the minimum fire rate. See: ADVANCED SETUP:4-20mA INPUT.

See section OPTIONAL FEATURES Using the 4-20ma input for extensive detail.

A 20mA signal will fire the boiler at the maximum firing rate, a 4 mA signal at the minimum rate. This means that a 20% (4mA) input signal is required to start the boiler, but if the boiler is classified as having example:4:1 turn down ratio, the boiler can only be fired as low as 25% of output. Any signal between 20% and 25 %, will fire the boiler at the minimum fire rate of 25%. If the MINIMUM setting of the boiler is set above the example: 4:1 turndown of 25% (such as 33%), a control signal change between 25% and 33% will not change the boilers firing rate. Once the control signal rises above the MINIMUM fire rate, the control signal will then affect control of the boilers fire rate.

The AA terminal, the HEAT DEMAND, and the H-Net NETWORK are the only inputs that will override the 4-20ma input.

Heating Method 4 AA Input

HIGH FIRE input Control: The AA input will fire the boiler at HIGH fire (maximum output of the boiler). No other inputs can override this input.

Figure 17

AA – High Fire Input

Heating Method 5 MODBUS communications

The fifth method uses an RS485 digital communications cable with the MODBUS protocol to control the boiler using the HNet network. The Boiler or Boiler network will run as in Method 1, but instead of the HEAT DEMAND input, a software form of the HEAT DEMAND input is used (40001: Boiler/System Enable/Disable). See: MODBUS COMMUNICATIONS section. The MODBUS protocol allows writing and reading registers using MODBUS commands.

Figure 18

The System Setpoint Timer also needs to be loaded periodically to allow the H-Net system to fallback to Method 1 in the event communications is lost from the Building Management System (BMS). This feature can be disabled in the ADVANCED SETUP:COMMUNICATIONS menu.

MODBUS Connections

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OPTIONAL FEATURES HeatNet Control REV 1.38-1

Protocessor option

An optional BACnet or LonWorks bridge module can be used to connect the MODBUS network to a BACnet or LonWorks network.

Figure 19

This method allows enabling and disabling the boiler or HNet system, changing setpoints, reading boiler(s) status, or temperatures remotely using digital commands. See the section: MODBUS Communications.

Using the 4-20mA Input

The 4-20ma input is designed to operate per the ISA-50.1 standard. It will support Type 2, Type 3, and Type 4 Transmitter/Receiver circuits.

The Type 2 and Type 3 circuit may use the supplied +24VDC and 24VDC RET connections (J10B) to power a remote transmitter. The –mA terminal will need to have a jumper connected to the adjacent 24VDC RET terminal to reference the signal ground.

With the type 4 configuration, multiple boilers (up to 5), may be connected in series using the –ma +ma –ma +ma scheme (no jumper to 24VDC RET). This allows one 420ma transmitter to control multiple boilers. A free-floating 250 ohm resistor is viewed by the BMS (or external control’s) 4-20ma transmitter across the + and –4-20ma terminals with this method.

Figure 20

MODBUS Connections

(OPTIONAL)

4-20mA Connections

Figure 21

The 4-20 ma input uses a 250 ohm sense resistor to convert the current to a voltage from 1 to 5 volts DC for the control to use. For this reason, a 1-5 VDC control voltage may also be used across the 4-20mA +/- input, but it still needs to supply the necessary current, i.e. 20mA. This resistor is located on the bottom side of the control board. When a 4.02 mA (adjustable) signal is sensed, the boiler will initiate a start sequence and fire the boiler at its minimum setting if the REMOTE ENABLE input is closed. This is typically 33%(3:1 turndown) or 25%(4:1 turndown) of the boilers output.

If jumper shunt JP3 is set to the PWM/0-10 position, the 420mA input will accept a 0-10 VDC signal (that can source 20mA). The operating range will be from 2-10 VDC or twice what was previously stated for the 1-5 VDC functionality. To convert a 0-10VDC signal to mA, divide by 500 (ohms).

If using a remote panel with a relay and a 4-20 mA transmitter for operation, connect the 4-20mA transmitter output from the remote panel to the member boilers using the floating 250 ohm method (type 4). The relay contacts on the remote panel will then be connected to the associated 4-20mA REMOTE ENABLE inputs on the associated boiler(s).

Setpoint Control functionality can be implemented remotely using the 4-20mA input. This function translates a 4 to 20mA control signal to a setpoint mapped from 50F to 220F. The feature is enabled in the SETPOINTS menu as: SETPT SOURCE 4-20mA.

ADVANCED SETUP:4-20mA INPUT. Also, when selecting; SETUP:SETPOINTS:SETPOINT SOURCE and selecting 4-20mA, the 4-20mA INPUT menu will be automatically entered.

The current at which the boiler will start can be selected. It is adjustable from 3.7mA to 5mA. Hysteresis of .1mA is always in effect. So, if the starting mA = 4.10mA the boiler will start when the control current applied achieves the value of

4.10mA. The boiler must drop .1mA below this to turn OFF,

4-20mA Enable Connection

Due to the inability of control voltage methods

(1-5, 2-10 VDC) to reject noise, the use of the 4-20mA control current is recommended. The control voltage methods may be less expensive, but are the least stable. If using a 0-10VDC control signal, a source current of 20mA is required.

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OPTIONAL FEATURES HeatNet Control REV 1.38-1

in this example 4.00mA. This hysteresis value is not adjustable.

When using the 4-20mA setpoint control, a band may be set at which the 4-20mA signal will operate over. The lower setpoint is defined as 4mA SETPOINT and the upper setpoint is defined as 20mA SETPOINT. The 4mA SETPOINT is linked to the BOILER START x.xxmA where this starting current is the lower setpoint. So if the 4mA SETPOINT is set to 130F and the 20mA SETPOINT is set at 180F the band will be established. Once a starting control current of BOILER START 4.1mA is applied, and the 4-20 REMOTE ENABLE INPUT is closed, the boiler will start and the setpoint will be set to 130F. If a control current of 10mA is applied, the boiler will track on a linear slope towards the 20mA SETPOINT settling at a SETPOINT of ~149F. As the current increases to 20mA, the SETPOINT will indicate 180F. The Default setting is 4mA SETPOINT: 50F, and 20ma SETPOINT 220F.

Anytime a new firmware version is uploaded to

the control, these values return to these defaults.

If using the direct modulation mode by applying a 4-20mA current, only the BOILER START x.xx setting applies.

The 4-20 mA input can also be set to HIGH PRIORITY. This can be set in menu: ADVANCED SETUP:4-20mA INPUT. This allows a member boiler to be taken offline and directly modulated by an external control. If the Master is using it for heating and the 4-20mA is set to HIGH PRIORITY, an external control can now output a 4-20mA signal which will take over the boiler’s fire rate. This is typically used for DHW control.

Circulator Pump Options

The control has provisions for a system pump and a local

pump/valve. This is to allow for primary/secondary loop configurations. The system circulator pump is implemented using the K4 relay and normally open contacts at J13 marked SYSTEM PUMP.

The pumps require motor contactors to isolate

the on-board relay contacts. The on-board relays should never be used to energize pumps directly.

Figure 22

Pump Connections

Operator

System Pump

Combustion Air Damper Local Pump/Valve

The System Circulator Pump is supported by (2) modes and a special feature.

DHW Pump/Valve

Alarm

1. The first mode will allow the circulator pump to remain

on, unless the control’s outside high air temperature setting has been met when using OUTDOOR AIR RESET.

2. The second mode will allow the circulator pump to be

turned on whenever there is a call for heat (any control input). This mode will stop the circulator pump when the call for heat is lost and the pump post purge time has been satisfied.

The summer pump jog is a special feature that can be selected when the system is in Warm Weather Shutdown (OUTDOOR RESET). The jog allows the system circulator pump to run for the pump purge time once a week. It can be set to any day of the week and will occur at 12:01 AM.

The system flow proving switch is implemented using System Water Flow on J5B. If a local flow switch is connected to the WTR FLW LOCAL interlock, the HeatNet control will wait up to 240 seconds to prove flow. This time is adjustable under SETUP:PUMP OPTIONS. The default flow proving time is 10 seconds. It can be increased to allow slower valves to open before flow is established. If flow is interrupted after it has been established, an error will be displayed and the boiler will cycle OFF. As long as there is a call for heat, every 10 minutes the circulator pump will try to re-establish flow and start the boiler again.

The Local Circulator Pump is supported by (3) modes and (2) features.

1. The first mode allows the circulator pump to remain on, unless the control’s outside high air temperature setting has been met when using Warm Weather Shutdown.

2. The second mode will allow the circulator pump to be turned on whenever there is a call for heat (any control input). This mode will stop the circulator pump when the call for heat is lost and the pump post purge time has been satisfied.

3. The third mode works much the same as mode 2, but it allows the inlet sensor (RETURN) to be used with the outlet sensor (SUPPLY) to keep the pump on until a delta (difference) temperature is met. A return temperature sensor is required for this mode, because the delta temperature (SUPPLY – RETURN) measured is across the boiler. In this mode, the post purge time is also used. After the delta temp has been met, the post purge time needs to expire before the pump is turned off. This mode works much the same as mode 2.

PUMP/VALVE OPTION: This is a special feature of the local circulator pump to prevent deadheading water flow when all boilers are off. When this feature is enabled, the master boiler will enable its local circulator pump/valve when NO boilers are running. If boilers are running in LOCAL override and not controlled by H-NET, but are

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OPTIONAL FEATURES HeatNet Control REV 1.38-1

WATER TEMP

180°F

Water temp @

visible to H-NET, the pump(s) on these boilers are presumed ON. In this situation, the master will not enable its circulator pump/valve unless it is running.

Another feature of the HeatNet Control is to control a local (primary) pump using a Variable Frequency Drive. This feature may be required when a secondary system pump is also variable speed. To enable this feature: SETUP:PUMP

OPTIONS:LOCAL PUMP PUMP/VALVE OPTION:LOCAL PUMP VFD: ON. Setting this Option to

ON will map the 0-10VDC control signal on J4 pins 7+ and 4- to the modulation rate. (2) wires need to be run from J4.7+ and J4.4- to the VFD’s input connection

Auxiliary Functions

Relay K5 and the terminal J13 is used to control a combustion air damper. The input J12B is used to detect the dry contact proof switch from the damper. A proof time of up to 4 minutes can be set before the boiler can start or an alarm condition will occur. The Combustion Damper can be setup in the SETUP:AUX FUNCTIONS menu.

The Master boiler controls the system damper, so in the event this damper fails to open, the system will not start. If the Master boiler’s system damper fails, then no call for heat will be made to the member boiler(s).

Each member boiler can control its own damper and is independent of the Master boiler when a call for heat is made to the member. This allows for separate dampers for each member boiler. They can be wired to J12B terminals 7 and 8.

If a common system damper is used (controlled by the Master boiler), each individual boiler must prove that the combustion air damper is open when it is placed in LOCAL. This may be done using J12B terminal 7on the all boilers wired to the damper’s prove switch. Terminal 7 is the sense input and terminal 8 is 24 VAC. Connecting a wire to terminal 8 is not recommended.

See Figure 35, Common System Damper Wiring, Page 42.

A separate/independent 24 VAC source is

recommended to be used for the damper prove switch when a common system damper is used. If you use terminal 8 to supply power from the Maste,r and the Master is powered OFF, no boiler will be allowed to fire due to the loss of power through the prove switch. A backup boiler will also need to have the damper relay contacts wired in parallel with the Master for when the Master is powered OFF.

A second wire on the Master J12B terminal 7 is then connected. The other end of this wire is then run to the first Member boiler J12B terminal 7. If another member boiler is present, a second wire can be connected to the first member boiler J12B terminal 7 and the other end connected to the other boiler J12 terminal 7. This method can be continued if

additional boilers are present. This input must be selected in the SETUP:AUX FUNCTIONS:COMBUST AIR DAMPER menu.

Outdoor Reset

The Outdoor reset feature allows the water setpoint temperature to change dynamically with the outside air temperature. It also provides an adjustable temperature that shuts the boiler/boiler system down when the outside temperature rises above it.

Figure 23

Outdoor Reset Curve, Typical

The above chart shows how the water temperature setpoint changes with the Outside air temperature. The four values of 180, 10 and 140, 70 are the default values:

LOW OA TEMP

WATER TEMP

HIGH OA TEMP

WWS Setpoint 72°F Outside air temperature

WARM WEATHER SD=ON If set to ON here

10°F

140°F

70°F

outside air temp

Water temp @

outside air temp

where Warm Weather

Shutdown occurs

The chart depicts what the water temperature setpoint will equal with a corresponding outside air temperature. At an outside temperature of 10F and below, the water temperature setpoint will be limited to 180F. With an outdoor temperature of 70F and above, the water temperature will be limited to 140F. The water temperature setpoint will track along the charts plotted line with corresponding outside temperatures.

The OR OVR (Outdoor Reset Override) input on J12A can be used to override this Outside Air Setpoint and maintain the water setpoint at the LOCAL or SYSTEM SETPOINT value

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OPTIONAL FEATURES HeatNet Control REV 1.38-1

when a contact is closed across this input. This can be used as a Domestic Hot Water demand input.

Another function of the OUTDOOR RESET is the Winter/Summer mode ( (W)arm (W)eather (S)hutdown). With the WWS SETPOINT set to 72F and WARM WEATHER SD set to ON, the boiler/system will enter summer shutdown when the Outside Air temperature rises above 72F. While in this state, the OR OVR input on J12A can be used to bring the boiler/system on to maintain the water setpoint at the LOCAL or SYSTEM SETPOINT value. During WWS operation, the System pump will not be enabled just the Local pump unless the SETUP:SYSTEM PUMP:OVR ENAB IN WWS is set to ON. This is the System Pump priority mode. When SETUP:SYSTEM PUMP:OVR ENAB IN WWS is set to OFF, the system pump will not come on while in WWS with the OR OVR override input closed.

Sensors

The Smith HeatNet control supports a standard 10K thermistor (Type ACI/10K-CP). These sensors can be calibrated to the control by entering the sensor menu and placing a precision 10k resistor on an input.

Immersion sensors must have wells.

Security

A password can be used to lock out control and setup features. It can be enabled, but is shipped in the disabled state.

Diagnostics

The Smith HeatNet control can display and identify faults in a meaningful way. If an interlock trips, it will be indicated in the main screen display, along with an audible alarm (mounted on control board) and a set of relay contacts will close. A record of this, with a time stamp, will also be entered into the log as an aide in the diagnosis of the event. The log can be downloaded and a histogram used to display the data. If using Modbus, BACnet, or LonWorks, software flag bits in registers are available.

Open and shorted sensors are checked continuously, so that in the event of a sensor failure, the system shuts down and the alarm relay is closed.

If a pump fails (flow switch required), or the flow switch fails, the boiler will cycle the start condition every 10 minutes in an attempt get the boiler restarted.

The damper fails to open and never closes its proof switch, a retry algorithm will attempt a retry. Every 10 minutes the damper relay will cycle and try to open the damper again.

If the H-Net control closes the last interlock string connected to the ignition control and the ignition control never closes its Blower Relay, the H-Net control will wait 2 minutes. The HNet control will then retry for the duration of the local pump post purge time and then retry the ignition sequence. During this time “retry strt” will be displayed in the status screen. After (5) attempts the H-Net control will lock out and display call service.

Communications

The Smith HeatNet control has the ability to communicate using the MODBUS protocol with a building management system. Most registers and functions are available for MODBUS access. Access is allowed using the RS485 MODBUS PORT connecter.

An optional BACnet or LonWorks bridge module can be used to connect the MODBUS network to a BACnet or LonWorks network. See Heating Method 5 control.

Failsafe Modes

Failsafe Modes have been added to help protect systems from no heat conditions. When using one of these modes ensure

that you connect any DAMPER control, or system pump control to safely allow operation with the assumption that

the MASTER boiler or BMS system is DOWN. (See Figures 35 and 36)

FAILSAFE REQUIREMENTS:

1. Since the Member boiler that will be assigned the Failsafe duty will always turn the system pump ON, this boiler should not be used for DHW heating. If the Master controls the system pump, then the Failsafe Member boiler would need to control the system pump in parallel with the Master boiler. Wire the System Pump contacts in parallel with the Master.

2. If the combustion air damper is used as a common system damper, the Failsafe boiler should be wired to control the damper in parallel with the Master boiler.

3. The Failsafe boiler should have the LOCAL SETPOINT set to the same setpoint temperature as the Master boiler’s SYSTEM SETPOINT.

Be aware that the boiler may start without a call-for-heat in the FAILSAFE MODES. FAILSAFE MODES can be

accessed through the:

SETUP:AUX FUNCTIONS:FAILSAFE MODES

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OPTIONAL FEATURES HeatNet Control REV 1.38-1

The following are types of Failsafe conditions.

1. Building Management System Failure

If a BMS system is controlling the setpoint and enabling the boiler system, a timer is provided to allow operation of the system in the event that communications are lost with the BMS system. The HeatNet boiler system will run locally if communications is lost and this timer expires due to the lack of being updated.

The system setpoint timer and system setpoint work in tandem to externally control (i.e. a BMS - building management system) the operating setpoint. The setpoint (countdown) timer should be loaded with a timeout value (in seconds) prior to writing the system setpoint. When the timer reaches zero, the control assumes that the BMS is no longer operating and the local setpoint (saved on the control) is reloaded. If the setpoint timer is not written, a

default timeout value of 60 seconds is assumed. The timer is automatically reloaded with the default value when a setpoint is written.

The BMS mode is always on and no menu

item is available.

2. Heat HeatNet Communications Lost

SETUP:AUX FUNCTIONS:FAILSAFE MODES: H-NET COMM LOST:

This mode allows a member boiler to run in LOCAL if

the communications link via the H-NET cable is lost. This includes the MASTER boiler losing its Control board, Communications board, or the power on the MASTER is switched OFF. When this MODE is set to ON, and if the member boiler loses it’s link (heartbeat packet over the H-NET cable) to the MASTER Boiler, this MEMBER will fire to the LOCAL setpoint.

The heartbeat packet over the H-NET cable

needs to be lost for 10 minutes

This mode may be used by the MASTER or MEMBER boiler, and can be used as a type of freeze protection. In this mode you may select which Sensor you wish to monitor, or you may opt to turn this mode OFF. If you select a sensor, you may then associate it with a temperature at which the boiler will turn ON. Once the temperature at this sensor falls below the LOW TEMP temperature the boiler will start and fire to its LOCAL setpoint. Once the Boiler reaches it’s setpoint it will turn OFF.

4. Using the base load relay.

Additional Features

1. Support for Domestic Hot Water using a temperature sensor or a dry contact from a tank thermostat. Also, a separate relay contact for a DHW pump or Valve is provided.

2. On-Board HeatNet and Modbus connections. A second terminal connector for daisy chaining the H-Net connections when using shielded wire.

3. Low fire hold switch for ease in calibrating.

4. A ‘U’ shaped socket system for mounting the Protocessor module. No other wiring connectors are required when connecting BACnet & LonWorks, other than the BACnet or LonWorks network cable.

5. Option input for special features. Support for Dual Fuel using a switch located on J12B terminals 5 & 6.

This MEMBER boiler will continue to run at the LOCAL setpoint until H-NET communications from the MASTER boiler is re-established.

Ensure that this Member boiler’s Damper and System pump control are configured correctly with the assumption that the Master is not powered. Also ensure that any other System settings related to outside air temperature sensing and system interlocks are set to provide safe operation.

3. Low Temperature Protection

LOW TEMP:OFF, SUPPLY, HEADER,

DHW, or RETURN

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OPTIONAL FEATURES HeatNet Control REV 1.38-1

JPS1

Domestic Hot Water Methods

The HeatNet control supports Domestic Hot Water control using (4) methods. When using the Domestic Hot Water methods, the wire jumper, JPS1 on each control board providing Domestic Hot Water, must be cut to limit the boiler’s maximum output temperature of 200F. Refer to the wiring Figures for control input and output locations.

Figure 24

Jumper JPS1

temperature setting (DHW DIFF). Boilers are started as long as the tank’s water temperature is below the (DHW SETPOINT – DHW DIFF). The first boiler is started immediately. The next boiler(s) is started after the ADD BOILER DELAY time expires. Boilers are not added when the temperature is above the (DHW SETPOINT – DHW DIFF) and below the DHW SETPOINT. Once the DHW SETPOINT is reached all boilers shut off. This limits the tank temperature to the setpoint + post purge time of the DHW pump.

Setting up this method is done via the menus in:

SETUP:DOMESTIC HOT WATER.

1. Connect a 10k thermistor from the DHW tank’s

sensor well to J10B terminals 1 & 2 on the DHW MASTER, or stand alone boiler. Wire any pump or valve from the DHW Pump relay (normally open) contact to control flow of the heating water into the tank’s coil.

2. Next, enter the DOMESTIC HOT WATER menu.

When prompted for DHW BOILER?, enter NO. We will enter YES when we are finished entering all parameters

3. Change the DHW SETPOINT to the desired

target temperature of the water in the tank. Once the control determines there is a call for DHW, the DHW SETPOINT is loaded and the Master boiler will target this new setpoint.

The following Domestic Hot Water setup information will include a walkthrough using the menus.

DHW METHOD 1: DHW Tank Sensor Input

DHW METHOD 1a: DHW Heating ONLY using a Single Boiler or a DHW MASTER and Member boiler(s) employing H-Net

This method utilizes a 10k thermistor connected to the DHW Sensor input of a DHW MASTER, or a stand alone boiler, and a DHW tank WITHOUT a HEADER sensor. It requires a DHW setpoint and other parameters to be set. This method is used when the water temperature in the tank needs to be no greater than the setpoint, with little overshoot of temperature. One of its limitations is that it may short cycle. It functions much in the same way a tank thermostat works.

This method works with (2) settings. A target tank water setpoint (DHW SETPOINT) and a start/add boiler

4. Now, change the DHW DIFF to the desired

differential. This setting corresponds to the minimum water temperature required in the tank. DHW heating will be initiated when the DHW tank’s water temperature is below the DHW SETPOINT – DHW DIFF.

5. How long the temperature of the tank stays below

the (DHW SETPOINT – DHW DIFF) is used to determine when boilers are started along with the ADD BOILER DELAY.

6. Scroll down to USE SENSOR? Press the

SELECT key and select YES, then press the SELECT key again. This will allow the boiler to

control the tank temperature using its sensor.

7. Press the DOWN arrow key again to position the

cursor beside the menu item DHW PRIORITY?. Setting this value to YES will turn OFF the system pump when the DHW mode is active. Setting this value to NO leaves the system pump on.

8. Press the DOWN arrow again and the menu item

POST PURGE should appear. This is the time that the DHW pump relay remains energized after the DHW SETPOINT has been satisfied. Once the tank has reached setpoint all boilers will shut off. Using the POST PURGE time to dump the boiler’s heat into the tank may heat the tank

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OPTIONAL FEATURES HeatNet Control REV 1.38-1

above the setpoint temperature. Care should be taken here.

9. Press the DOWN arrow again and the menu item:

DHW MASTER?, will be displayed. If this item is set to YES, once the DHW MASTER receives a HEAT DEMAND signal, it will call other boilers it has available using H-Net. Setting to NO, requires no Heat Demand signal, and will only enable the single boiler when the DHW Tank Temperature drops below (DHW SETPOINT – DHW DIFF).

DHW MASTER? YES is to be only be used

WITHOUT a Header Sensor

10. Finally, go to DHW BOILER?. Select YES. If

JPS1 has not been cut, a message will appear instructing to do so. Once this is done, the stand alone boiler will control the temperature in the tank, or the DHW Master will control the temperature in the tank using as many boilers as it has available on H-Net.

DHW BOILER? Does not need to be set to

YES on MEMBER boilers, only the DHW MASTER or on a stand alone boiler providing DHW.

JPS1 MUST be cut on all boilers providing DHW.

3. Change the DHW SETPOINT to the desired

target temperature of the water in the tank. Once the control determines there is a call for DHW, the DHW SETPOINT is loaded and the Master boiler will target this new setpoint.

4. Now, change the DHW DIFF to the desired

5. Since the same the ADD BOILER DELAY time

is used for space heating and DHW, how long the temperature of the tank stays below the (DHW SETPOINT – DHW DIFF) has to be considered when setting the ADD BOILER DELAY.

6. Scroll down to USE SENSOR? Press the

SELECT key and select YES, then press the SELECT key again. This will allow the boiler to

control the tank temperature using its sensor.

7. Press the DOWN arrow key again to position the

cursor beside the menu item DHW PRIORITY?. Setting this value to YES will turn OFF the system pump when the DHW mode is active. Setting this value to NO leaves the system pump on.

DHW METHOD 1b: Combo DHW and Space Heating using a MASTER Boiler and Member boiler(s) employing H-Net

This method utilizes a 10k thermistor connected to the DHW Sensor input of a MASTER boiler, a DHW tank AND a HEADER sensor. This Method works the same as DHW METHOD 1a, but also has the ability to provide space heating.

Setting up the DHW portion of this method is done via the menus in: SETUP:DOMESTIC HOT WATER. For information on setting up the space heating portion of the method Refer to Heat Demand Control Method 1 located in the CONTROL METHODS section on page 22.

1. Connect a 10k thermistor from the DHW tank’s

sensor well to J10B terminals 1 & 2 on the MASTER, and connect a Header Sensor to the SYSTEM HEADER input. Wire any pump or valve from the DHW Pump relay (normally open) contact to control flow of the heating water into the tank’s coil.

2. Next, enter the DOMESTIC HOT WATER menu.

When prompted for DHW BOILER?, enter NO. We will enter YES when we are finished entering all parameters

8. Press the DOWN arrow again and the menu item

POST PURGE should appear. This is the time that the DHW pump relay remains energized after the DHW SETPOINT has been satisfied. If there is no HEAT DEMAND signal, once the tank has reached setpoint all boilers will shut off, and the post purge time will begin. If there is a HEAT DEMAND Signal when the tank has reached setpoint, the boilers will continue running to provide space heating, and the DHW pump relay will be de-energized immediately. Using the POST PURGE time to dump the boiler’s heat into the tank may heat the tank above the setpoint temperature. Care should be taken here.

9. Press the DOWN arrow again and the menu item:

DHW MASTER?, will be displayed. Set it to NO for this DHW Method.

NOTE: This DHW Method requires no Heat Demand signal to control the temperature in the tank. As soon as the DHW Tank Temperature drops below (DHW SETPOINT – DHW DIFF) a boiler will be enabled.

NOTE: DHW MASTER? YES is only to be used WITHOUT a Header Sensor. When both a Header Sensor and a DHW Tank Sensor are installed, because it has a HEADER Sensor, the Boiler will recognize itself as a MASTER. When DHW BOILER? is also set to YES, the

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OPTIONAL FEATURES HeatNet Control REV 1.38-1

MASTER will automatically call on other boilers when the DHW Tank Temperature drops below (DHW SETPOINT – DHW DIFF) even when no Heat Demand signal is present. However, the MASTER will only enable boilers for space heating in response to a Heat Demand signal.

10. Finally, go to DHW BOILER?. Select YES. If

JPS1 has not been cut, a message will appear instructing to do so. Once this is done, the MASTER boiler will control the temperature in the tank using as many boilers as it has available on H-Net.

DHW BOILER? Does not need to be set to

YES on MEMBER boilers, only the MASTER boiler.

JPS1 MUST be cut on all boilers providing

DHW.

DHW METHOD 2: DHW Header Sensor Input

1. This method will control a tank temperature when

the tank temperature setpoint needs to be maintained for extended periods with minimal cycling. Multiple boilers can be used via the HNet, as this method employs the same PID algorithm as for space heating. For this method, a tank temperature band needs to be tolerated. JPS1 MUST be cut on all boilers providing DHW to ensure the maximum output temperature of all boiler is limited for DHW operation.

2. Use the Heat Demand Control Method 1

located in the CONTROL METHODS section on page 22. Instead of placing the Header sensor in the Header pipe, place it in a well in the tank.

The temperature at which boilers are staged ON, and then OFF is controlled by the SETUP:BOILERS:HEAT BAND differential. This can be understood by referring to the INTRODUCTION section on the MASTER in the beginning of this manual.

This differential has the added effect of heating the tank above the tank’s setpoint temperature. If the tank setpoint is set to 140F and the heat band is set to 10F, then the tank temperature will rise to 145F before the first boiler turns off (setpoint =140F +/-heat band/2). With (2) boilers running, the SHED BOILER DELAY time could add to the tank temperature. So, to ensure that all boilers are shut off at the upper point of the heat band, set the SHED BOILER DELAY time to 0. This will effectively turn off all boilers at the upper heat band point of: (example) 145F.

Now, there is one more thing to consider, the pump’s post purge time. Dumping the heat from all boilers (that were running) using a pump post purge cycle will have an effect on the tank’s water temperature. Consider this when establishing the local pump’s POST PURGE TIME.

3. Connect the Local Pump relay contact on J13 to

enable the DHW pump. Set its post purge time to dump the boiler’s heat into the tank when the boiler shuts off. Be aware that this may heat the

tank above the setpoint’s upper heat band temperature.

4. Enable the system by placing the

LOCAL/REMOTE switch on the Master to the LOCAL position.

DHW METHOD 3: Space Heating with DHW Override

This method is for controlling DHW utilizing a tank thermostat connected to a Master or Member boiler. This method can be used instead of the 10k thermistor sensor. When the thermostat contact closes across the input OA OVR (J12A .7 & .8), the control will sense this closure and enter the DHW heating mode.

In this mode, the boiler will fire to 100% and be regulated by the OPERATE LIM setting located in SETUP:SETPOINTS. The OP LIM BAND can be used to keep the boiler from short cycling too much by limiting the firing rate as it approaches the OPERATE LIM.

1. Wire the dry contact from the thermostat on the

tank to the input on J12A terminal 7 & 8. Also, at this time wire any pump or valve from the DHW Pump relay (normally open) contact (J13 terminals 9, 10) to control flow of the heating water into the tank’s coil.

2. Enter the DOMESTIC HOT WATER MENU.

When prompted for DHW BOILER?, enter NO. We will enter YES when we are finished entering all parameters

Follow the same steps as used to program the 10k thermistor sensor method, but when asked to USE SENSOR?, select NO.

Set the DHW MASTER to NO. A thermostat can only control (1) boiler. H-Net is not available with a thermostat on the tank.

Go to the DHW BOILER?, enter and select YES. The Master or Member will now control the temperature in the tank.

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OPTIONAL FEATURES HeatNet Control REV 1.38-1

DHW METHOD 4: DHW using Direct Control

The 4-20 mA input can be set to the HIGH(est) PRIORITY. This can be set in menu: ADVANCED SETUP:4-20mA INPUT. This allows a member boiler to be taken offline and directly modulated by an external control.

If the Master is using it for heating and the 4-20mA is set to HIGH PRIORITY, an external control can now output a 4-20mA signal which will take over the boiler’s fire rate and override all other heating demand inputs. This is typically used for DHW control.

Dual Fuel Option

The OPTION control input allows for optional functions. This input designated as the ‘OPTION” input (J12B terminals 5 &

6) can be used as a programmed input. The menu:

ADVANCED SETTINGS:SYSTEM:OPTION,

can be used to set the DUAL FUEL option if equipped. It assigns the K8 relay contacts on J4.1 &.2 to this function if not using the Base Load Option.

The Dual Fuel option functionality is the same for a Master or Member.

1. When the Option input switch is open, the Solid State

Relay (K8) has its contacts open on J4, between pins 1 and 2. FUEL 1

2. When the Option input is closed, the control detects a

change on this input and stops the boiler (if running).

3. Once the boiler stops, K8’s contacts close. This allows

the Fuel relay to energize and change the fuel. The message FUEL CHNG will be displayed in the Status Line. FUEL 2

4. If there is still a call for heat, the boiler restarts.

5. If the Option input now opens, the change is detected and

the cycle repeated.

A warning message appears when the Stack Temperature exceeds 550F. The Alarm relay does not close and no action is taken. The message is the only indication. Service is usually required or needs to be scheduled (cleaning and checkup).

An alarm message appears when the stack temperature exceeds 700F. The alarm contact also closes to indicate a problem with the boiler. The next thing that happens is the boiler is limited to firing at ½ it’s called for rate. In order to clear the alarm condition the Stack temperature must fall below the warning temperature of 550F. This will also remove the firing rate limit restriction.

A high Stack Temperature indicates that heat energy from the combustion process is not being transferred efficiently to the water. Overall boiler efficiency is reduced and damage to the boiler could result. At this point action should be taken immediately to correct the problem.

An additional function has also been included

to help protect the boiler. AUX FUNCTIONS:HEAT EXCHANGER:LOW TEMP HOLD is used to hold the boiler at the low fire rate until the return temperature exceeds the set value. The default is 130F, but can be increased to 160F

Interlock Selection

The Smith HeatNet control allows selection of interlocks to monitor. An interlock can be monitored by connecting a wire from the point after the interlock to the appropriate terminal on J5 of the control board.

Figure 25

Interlocks

Stack Temperature

The Smith HeatNet control monitors the stack temperature and sets a warning or an alarm message in the event that the Stack Temperature exceeds a predefined threshold. The Stack Temperature is monitored since it is a good indicator of the boilers health. The sensor that measures this temperature is a 1k ohm RTD type sensor which can handle the higher temperatures of the flue gas.

As an example: To connect the Local Water Flow switch to J5 first identify the normally open contact on the flow switch. Next, attach a wire to this point. Now, run the wire through a rigid conduit to the control and connect the wire to “J5B,

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OPTIONAL FEATURES HeatNet Control REV 1.38-1

WTR FLW LOCAL”. Push the black latching lever on J5B down to secure the wire.

Now, go to the keypad and hold down the ESC key until the menus appear (about 5 seconds). Using the arrow keys, position the arrow next to ADVANCED SETUP and press the ENTER key. Now, using the DOWN arrow key, scroll down until the SYSTEM menu appears. Press the ENTER key. Again, press the ENTER key to enter the CONFIGURE INTERLOCKS menu. Use the DOWN or UP arrow keys to select LOCAL FLOW. Press the ENTER key to change the setting to “ON” using the Arrow keys. The interlock is now enabled and will detect and prove Local Water Flow. Press the ESC key (4) times to return to the Main Screen.

If an interlock input is used it will be set to ON. If not used, set it to OFF. When an interlock is not made and it is set to ON, a message will be displayed along with a warning. The boiler/system will not start or will stop running until the interlock fault condition clears.

Firmware Loading

The HeatNet control supports a flash drive for loading firmware. This is in addition to the loading of firmware through the USB port.

Firmware versions can use either the flash drive port for uploading, or the USB port along with a pc/laptop computer.

Firmware files must be stored in a directory on the flash drive in: \Firmware. The firmware files need to be placed in this directory. As an example:

Once the files are placed on the flash drive, press and hold the BACK key for 5 seconds to enter the Setup

menus. Select the ADVANCED SETUP: SYSTEM: LOAD FIRMWARE. Select YES using the arrow keys and press the SELECT key. Select YES when asked, ARE YOU SURE?, and press the SELECT key. When SOURCE is displayed, select USB DRIVE and press the SELECT key. A message will be displayed to ensure to REMOVE USB CABLE, if it is connected. After the SELECT key is pressed, PLEASE WAIT… will be displayed to check that the cable has been removed.

Now, INSERT USB DRIVE will be displayed. Plug the flash drive into J6. Press the SELECT key. PLEASE WAIT… will be displayed as the control reads the flash drive. The firmware file names will be displayed on the top line. Cycle through the files on the flash drive using the arrow keys. When the file to download appears on the top line, press the SELECT key to begin download/update.

The LOADING: xxxxxx message will appear and a number will increment as the file is loaded. Once the file finished loading, a series of beeps will acknowledge this. Next, a chirping will be heard which indicates the process of burning the new firmware code into the control’s microcontroller. During this time the power can not be lost/cycled or the firmware will become corrupt. If this does occur, a laptop/pc will be required to load the firmware via the USB port.

Once the new Firmware is loaded the ADVANCED SETUP menu needs to be entered and then the LOAD DEFAULTS menu. Select the FACTORY RESET and select YES twice to load the factory defaults. The Flash Drive does not automatically load the default settings as the PC/Laptop loading does.

Page 32

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WIRING CONNECTIONS HeatNet Control REV 1.38-1

Wiring Connections

Figure 26

Power Connections

Page 33

Page 34

WIRING CONNECTIONS HeatNet Control REV 1.38-1

Figure 27

L 1

L 2

A C

G N D

Heating Method 1 H-Net Master/Member

- 1

T P

J 1

J 1 4

N T E R L O

J 5 B

C K S

G N I

T I

O N C O

5 A

T R O L

L 1

P O W E R S

R V I

E A C

G N D

Y A L E R _ 7 7 T

- 1

T P

J 1 0 A

J 4

201

7 7 7 T

2 6

2 4

D C

- 0

W P

a m

0 2

- 4

2 2 J

4 D

5 D

0 2 J

6 J

8 J

- B

+ A

4 S

S U B D O M

1 Y

1 2 J

2 J

- B

1 J

T E N

B +

7 1

3 S

1 S P J

Close this contact to override the Outdoor Reset slope and run at the Domestic Hot Water Setpoint.

The DHW Pump NO contact will also close.

Page 34

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WIRING CONNECTIONS HeatNet Control REV 1.38-1

Figure 28

Unused

WTR FLW LOCAL

EXT OPERAT

SPARE 4

GAS PR

VFD

LWCO

SYSTEM WTR FLOW

Unused

AIR PR SW

HIGH LIMIT

VALVE ALRM

FLAME SAFE ALARM

BLOWER M

PILOT VALVE

MAIN VALVE

AC GND

Heating Method 2 and 4: AA-High Fire and High/Low Master or Member Boiler

0-10VDC

AC GND

24VAC TRANSFORMER

INTERLOCKS

IGNITION CONTROL

J5AJ5B

POWER SERVICE

OPERATOR

HI/LO NO

J14

24V

RET

KN/F-SERIES

KNSMITH R1.0

HEAT NET

K1a

BOILR START

J13

2 3

Jumper 2-3

for 135 ohm

02-2008

K4a

T77_RELAY

SYSTEM

DAMPER

PUMP

Method 4 Close this contact to run boiler at High Fire

1 AMP

4-20mA

MODULATION CONTROL

K5 K6

K5a

T77_RELAY

LOCAL

PUMP/VALVE

0-10VDC

OUTPUT

W BR

K7a

K2a

K6a

T77_RELAY

DHW PUMP/

ALARM

AUX STATUS

Aux Status/

ALARMLOCAL PUMPDAMPERSYSTEM PUMP

DHW PUMP

J12A

AIR

WTR OUT OUTSIDE

-+-+

J10A

0-10

4-20ma

PWM/0-10

PWM

J18

J10

OUTPUT

VFD

U26

4-20mA/

HEAT

0-10v

DEMAND

ENABLEHIGH FIRE

WTR IN

U4 PROTOCESSOR

J16

J19

BZ1

8811

HEADER RETURN SUPPLY SYSTEM

-+-+

DISPLAY/KEYPAD

DHW TANK

DAMPER

+-+

SIP1

J20

T2T1OR OVR

OPTION

Method 2 Stage Control Inputs: Stage 1, Stage 2

1 2

ALRM RST

SPARE 2

Sense

DAMPER

J22

RET

J12B

24VDC

LOW FIRE

24VAC

+ -

4-20mA

24VDC

J10B

JP3

PWM/0-10

4-20ma

J12

JP4

A+ B-

MODBUS

J21

A+ B-

J11

HNET

A+ B-

J17

CAL

JPS1

NORM

Page 35

Page 36

WIRING CONNECTIONS HeatNet Control REV 1.38-1

Figure 29

Heating Method 3 – 4-20mA

24 VDC

Unused

WTR FLW LOCAL

EXT OPERAT

SPARE 4

GAS PR

VFD

LWCO

SYSTEM WTR FLOW

Unused

AIR PR SW

HIGH LIMIT

VALVE ALRM

FLAME SAFE ALARM

BLOWER M

PILOT VALVE

MAIN VALVE

L 1

L 2

A C G N D

J 1 0 A

Y A L E R _ 7 7 T

4-20 mA/0-10 V DC 4-20mA/0-10 VDC +

24 VDC Return

AIR

WTR OUTOUTSIDE

-+-+

0-10

4-20ma

PWM/0-10

J18

OUTPUT

4-20mA/

ENABLEHIGH FIRE

PWM

J10

VFD

0-10v

DEMAND

U 2 6

HEAT

HEADERRETURNSUPPLY SYSTEM

WTR IN

-+-+

U4 PROTOCESSOR

2 J

201

DISPLAY/KEYPAD

BZ1

8811

T2T1OR OVR

Closing a contact

DAMPER

OPTION

ALRM RST

DHW TANK

+-+

SIP1

4-20mA

2 4

SPARE 2

+ -

8 J

LOW FIRE

C A V 4 2

W P

Jumper in this

a m 0

- 4

position: 4-20mA

- B

JP4

4 S

S U B D

O M

1 Y

1 2 J

- B

1 J

T E N

7 1

CAL

1 S P J

NORM

2 2 J

4 D

5 D

J12B

e s n e S

DAMPER

Modulation Control Input

HI/LO NO

1 AMP

4-20mA

Y A L E R _ 7 7 T

DAMPER

MODULATION CONTROL

K5 K6

K5a

LOCAL

PUMP/VALVE

Y A L E R _ 7 7 T

24VAC TRANSFORMER

N T E R L O

5 B

K S

G N I

T I

O N C O N

5 A

R O L

L 1

P O W E R

S E

L 2

R V I

C E

A C G N D

J 1

OPERATOR

J 1 4

24V

RET

KN/F-SERIES

KNSMITH R1.0 HEAT NET

K1a

Y A L E R _ 7 7 T

BOILR START

J13

SYSTEM PUMP

1 2 3

02-2008

K4a

- 1

W BR

J 4

K7a

K2a

K6a

DHW PUMP/

ALARM

AUX STATUS

Aux Status/

ALARMLOCAL PUMPDAMPERSYSTEM PUMP

DHW PUMP

J12A

here enables the 4-20mA control signal input.

This Method allows direct modulation of the boiler based on a 4-20 mA control signal. A control capable of transmitting a 4-20mA/0-10 VDC control signal for the purpose of modulating a boiler and to control a common system temperature must be used with this method.

4-20mA setpoint control functionality

This function translates a 4 to 20mA control signal to a setpoint mapped from 60F to the Max Boiler temp. The control of the system works identically to Method 1, but allows the setpoint to be controlled remotely. The minimum current accepted is 3.7mA and is adjustable to 5mA. It is mapped to the 4mA setpoint in the 4-20mA INPUT menu. The maximum 20mA input setpoint is mapped to the 20mA setpoint also adjustable in the 4-20mA INPUT menu. To get the approximate setpoint, divide the 4-20mA current sent by .09. Example: 10ma /.09 = 110F. The feature is enabled in the SETPOINTS menu as: SETPT SOURCE 4-20mA

NOTE: If using a 0-10 VDC signal multiply any references to current in the manual by .5. Example: 5ma * .5 = 2.5 VDC

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WIRING CONNECTIONS HeatNet Control REV 1.38-1

Figure 30

Unused

WTR FLW LOCAL

EXT OPERAT

SPARE 4

GAS PR

VFD

LWCO

SYSTEM WTR FLOW

Unused

AIR PR SW

HIGH LIMIT

VALVE ALRM

FLAME SAFE ALARM

BLOWER M

PILOT VALVE

MAIN VALVE

L 1

L 2

A C G N D

Heating Method 5 MODBUS (Optional BACnet or LonWorks bridge)

- 1

HI/LO NO

1 AMP

4-20mA

Y A L E R _ 7 7 T

DAMPER

MODULATION CONTR OL

PUMP/VALVE

K5 K6

K5a

Y A L E R _ 7 7 T

LOCAL

24VAC TRANSFORMER

N T E R L O

5 B

K S

G N I

T I

O N C O N T

J 5

O L

L 1

P O W E R S E

V I

C E

A C G N D

J 1

OPERATOR

J 1 4

24V

RET

KN/F-SERIES

KNSMITH R1.0 HEAT NE T

K1a

BOILR START

J13

1 2 3

02-2008

K4a

Y A L E R _ 7 7 T

SYSTEM

PUMP

W BR

J 4

K7a

K2a

K6a

Y A L E R _ 7 7 T

DHW PUMP/

ALARM

AUX STATUS

Aux Status/

ALARML OCAL PUMPDAMPERSYSTEM PUMP

DHW PUMP

J12A

AIR

WTR OUTOUTSIDE

WTR IN

-+-+

J 1 0 A

0-10

4-20ma

PWM/0-10

U 2 6

HEAT

DEMAND

PWM

J18

J10

OUTPUT

VFD

PROTOCESSOR

J 1 6

BZ1

8811

4-20mA/

0-10v

ENABLEHIGH FIRE

J 1 9

DISPLAY/KEYPAD

HEADERRETURNSUPPLY SYSTEM

-+-+

201

T2T1O R OVR

ALRM RST

DHW TANK

DAMPER

+-+

SIP1

0 2 J

OPTION

4-20mA

2 4

4 D

5 D

J12B

8 J

D C

LOW FIRE

C A V 4 2

+ -

4 V D C

2 1 J

JP4

6 J

1 1 J

T E N H

7 1 J

J 1

Modbus RJ45

a m 0 2

- 4

1 Y

1 2 J

CAL

1 S P J

NORM

Modbus

Shielded or Twisted

pair w ire to Building

Managem ent Sys tem

4 S

S U B D O M

2 J

DIP Switch shown :Not

- B

Terminated

+ A

Push both white switches dow n to

- B

enable B ACnet, Lonw orks, or

+ A

Modbus termination.

3 S

SPARE 2

2 2 J

e s n e S

DAMPER

RJ45 Configuration and IP connection

NOTE: D o not plug th e Protocessor

There are pin headers located on the control (‘U’ s haped) that the Protocessor bridge module plugs in directly. Align the

module in with po wer on o r

Protoces sor module may be d amaged .

sockets on the Protoc essor with the pin he aders on the control, then press into place. All power for the bridge is supplied by the version 2.x control. Co mm unication from the Protocessor bridge to the H-N et control is also handled through the socke ts.

Next, connect the BACnet or LonW ork s network cable to th e

Protocessor B ridg e Module Plug-in.

LonWorks or BACnet bridge w hich

Can be used instead of the

MODBUS input.

Protocessor module or configure the bridge using the software tools. Once connected use the DIP switch to enable termination.

Shieded or Twisted Pair Connecti on (MSTP/ LonWorks)

Additional Bulletins and Instructions for Configuring BACnet or LonWorks are available on the website.

Page 37

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WIRING CONNECTIONS HeatNet Control REV 1.38-1

Figure 31

Interlocks

1. Connect a wire after the boiler interlock to the interlock terminal. Inputs are 120 vac.

2. Enable the interlock to monitor it in the ADVANCED SETUP:SYSTEM menu

The highest priority is the Lowest Number. The highest priority is displayed as the fault.

Ignition Handshake Signals

Relays, Interlocks and Boiler Status

Priority

Unused

Local Water Flow Switch

External Operator

Spare for user or Factory

Gas Pressure (High & Low)

Variable Frequency Drive

Low Water Cutoff

System Water Flow Switch

*High Limit (Use Operator IN)

Air Proving Switch

Valve Alarm

Flame safeguard alarm

*Blower

*Pilot Valve

*Main Valve

*Required

Unused

WTR FLW

LOCAL

EXT OPERAT

SPARE 4

GAS PR

VFD

LWCO

SYSTEM WTR FLOW

Unused

AIR PR SW

HIGH LIMIT

VALVE ALRM

FLAME SAFE ALARM

BLOWER M

PILOT VALVE

MAIN VALVE

L 1

L 2

A C

G N D

24VAC TRANSFORMER

J 5 B

J 5 A

L 1

P O W E R

E R V I

C G N D

J 1

N T E R L O C K S

G N I

T I

O N C O N T R O L

J 1 4

24V

F 1

KN/F-SERIES

KNSMITH R1.0 HEAT NET

K1a

BOILR START

OPERATOR

USB Firmware Update jack

HI/LO NO

1 AMP

02-2008

K4a

Y A L E R _ 7 7 T

DAMPER

4-20mA

MODULATION CONTROL

K5 K6

K5a

Y A L E R _ 7 7 T

LOCAL

PUMP/VALVE

1 2 3

24V RET

F 3

Y A L E R _ 7 7 T

J13

SYSTEM

PUMP

W BR

J 4

K7a

K2a

ALARM

K6a

Y A L E R _ 7 7 T

DHW PUMP/

AUX STATUS

Aux Status/

ALARMLOCAL PUMPDAMPERSYSTEM PUMP

DHW PUMP

J12A

AIR

WTR OUTOUTSIDE

-+-+

J 1 0 A

0-10

4-20ma

PWM/0-10

J18

J10

OUTPUT

VFD

U 2 6

4-20mA/

HEAT

DEMAND

0-10v

ENABLEHIGH FIRE

PWM

U4 PROTOCESSOR

8811

WTR IN

J 1 6

J 1 9

DISPLAY/KEYPAD

BZ1

HEADERRETURNSUPPLY SYSTEM

-+-+

201

ALRM RST

4-20mA

DHW TANK

SPARE 2

DAMPER

+ -

2 2 J

4 D

5 D

8 J

J12B

e s n e S

DAMPER

LOW FIRE

C A V 4 2

D C

a m

0 2

- 4

- B

JP4

4 S

S U B D

6 J

O M

1 Y

1 2 J

2 J

- B

Calibrate

1 J

T E N H

7 1 J

Switch

- B

+ A

CAL

1 S P J

NORM

+-+

SIP1

0 2 J

T2T1OR OVR

OPTION

Low Fire Hold Switch

Operator used to

Start Boiler

Enables System

Pump

Local Pump

Alarm Closes on

Enables

Domestic Hot Water Pump/Valve

Combustion Air Damper

prove switch

Fault

Combustion Air

Damper

Page 38

Page 39

WIRING CONNECTIONS HeatNet Control REV 1.38-1

Figure 32

L 1

L 2

A C

G N D

Temperature Sensors

J 1 4

N T E R L O

5 B

K S

G N I

T I

O N

C O N T

J 5

O L

L 1

P O W E R

S E

V I

C E

A C

G N D

J 1

Y A L E R _ 7 7 T

- 1

J 4

J 1 0 A

0 2 J

201

2 4

2 2 J

4 D

5 D

8 J

2 4 V D C

J 1

W P

a m 0

- 4

- B

+ A

4 S

S U B D

6 J

O M

1 Y

1 2 J

2 J

- B

1 1

Y A L E R _ 7 7 T

_ 7 7 T

T E N H

7 1 J

+ A

- B

+ A

3 S

1 S P J

Page 39

Page 40

WIRING CONNECTIONS HeatNet Control REV 1.38-1

Figure 33

Controlling the Mod Motor

Modulation Control Outputs

The figure shows the (2) methods for

controlling a modulation actuator.

Relay K8 NO Contact.

1. Dual Fuel

2. High/Low

Jumper shunt in this position (2-3) allows 135 ohm control for actuators:

Jumper shunt in the (1-2) position to allow 4-20 mA control.

24VAC TRANSFORMER

J 1 4

N T E R L O C K S

G N I

T I

O N

C O N T R O L

24V

F 1

KN/F-SERIES

KNSMITH R1.0 HEAT NET

BOILR START

OPERATOR

Unused

WTR FLW LOCAL

EXT OPERAT

SPARE 4

GAS PR

VFD

LWCO

SYSTEM WTR FLOW

Unused

AIR PR SW

HIGH LIMIT

VALVE ALRM

FLAME SAFE ALARM

BLOWER M

PILOT VALVE

MAIN VALVE

L 2

A C G N D

J 5 B

J 5 A

L 1

P O W E R

S E

V I

C E

A C

G N D

J 1

For Actuators that utilize a 4-20 mA signal. J4 terminals 3+ and 4J5: position 1-2

- 1

ALARM

W BR

K6a

Y A L E R _ 7 7 T

DHW PUMP/

AUX STATUS

J 1 0

J 4

K7a

K2a

Y A L E R _ 7 7 T

Aux Status/

ALARMLOCAL PUMPDAMPERSYSTEM PUMP

DHW PUMP

J12A

Y A L E R _ 7 7 T

HI/LO NO

1 AMP

4-20mA

24V RET

F 3

K1a

Y A L E R _ 7 7 T

J13

SYSTEM PUMP

02-2008

K4a

Y A L E R _ 7 7 T

DAMPER

MODULATION CONTROL

K5 K6

K5a

Y A L E R _ 7 7 T

LOCAL

PUMP/VALVE

For Actuators that utilize a 135 ohm Potentiometer. J5: position 2-3 R, W, & B J4 terminals: 4=R, 5=W, 6=B

U 2 6

HEAT

DEMAND

AIR

WTR OUTOUTSIDE

J18

OUTPUT

PWM/0-10

4-20mA/

ENABLEHIGH FIRE

-+-+

0-10

PWM

J10

VFD

PROTOCESSOR

0-10v

8811

4-20ma

HEADERRETURNSUPPLY

DHW TANK

SYSTEM

WTR IN

DISPLAY/KEYPAD

BZ1

DAMPER

-+-+

+-+

SIP1

0 2 J

201

T2T1OR OVR

OPTION

ALRM RST

4-20mA

2 4

SPARE 2

2 2 J

4 D

5 D

8 J

+ -

2 4 V D C

J 1

W P

a m 0

- 4

- B

JP4

4 S

S U B D

6 J

O M

1 Y

1 2 J

2 J

- B

+ A

- B

+ A

CAL

1 S P J

NORM

e s n e S

DAMPER

J12B

LOW FIRE

C A V 4 2

1 1 J

T E N H

7 1 J

Page 40

Page 41

WIRING CONNECTIONS HeatNet Control REV 1.38-1

Figure 34

OUTDOOR

SENSOR

North Away

From Exhaust

Typical Single Boiler System

LOCAL PUMP

ENABLE #8

FLOW PROVE

#10

RETURN SENSOR

COMBUSTION

AIR DAMPER

ENABLE #7 PROVE #11

STACK

SENSOR #6

BOILER

HEADER SENSOR

(Determines Master Boiler) #4

SYSTEM PUMP

ENABLE #14

FLOW PROVE #9

SUPPLY

SENSOR

DHW RETURN

DHW SUPPLY

DHW TANK AQUASTAT

#13

DHW TANK

SENSOR #5*

DHW TANK

DHW PUMP

ENABLE #12

Unused

WTR FLW LOCAL

EXT OPERAT

SPARE 4

GAS PR

VFD

LWCO

SYSTEM WTR FLOW

Unused

AIR PR SW

HIGH LIMIT

VALVE ALRM

FLAME SAFE ALARM

BLOWER M

PILOT VALVE

MAIN VALVE

- 1

MOD

W BR

J 4

U16

U17

DHW PUMP/

AUX STATUS

CP1

CP4

RP2

CP2

CP3

C35

U13

K7a

K2a

Aux Status/

ALARMLOCAL PUMPDAMPERSYSTEM PUMP

DHW PUMP

J12A

U 2 4

1 1 U

U 7

K6a

Y A L E R _ 7 7 T

ALARM

HI/LO NO

1 AMP

4-20mA

24VAC TRANSFORMER

#10

T E R L O C

J 5

G N I

T I

O N C O N T

5 A

O L

L 1

L 2

A C

G N D

L 1

P O W E R S E

V I

C E

A C G N D

J 1

J 1 4

HIGH LIMIT

IGN

Control

OPERATOR

24V

RET

KN/F-SERIES

KNSMITH R1.0 HEAT NET

K1a

Y A L E R _ 7 7 T

BOILR START

#14

J13

SYSTEM PUMP

2 3

R V 1

02-2008

K4a

o r e p

m u J

Y A L E R _ 7 7 T

MOTOR

MODULATION CONTROL

0 9 C

9 3 C

6 9 C

K5 K6

K5a

Y A L E R _ 7 7 T

#7 #8 #12

LOCAL

DAMPER

PUMP/VALVE

AIR

WTR OUTOUTSIDE

-+-+

J 1 0 A

#2 #3 #4 #5 #6

0-10

4-20ma

PWM/0-10

U22

U14

C 9 7

U20

U 3 5

U 2 6

PWM

J18

J10

OUTPUT

VFD

U10

JP1

U15

CLK

U34

WTR IN

U4 PROTOCESSOR

U18

VPP

VCC

GND

DAT

BZ1

U27

201

R P 1

DISPLAY/KEY PAD

HEADERRETURNSUPPLY SYSTEM

-+-+

JP2

#13

8811

4-20mA/

HEAT

DEMAND

0-10v

ENABLEHIGH F IRE

T2T1OR OVR

ALRM RST

SPARE 2

2 2 J

4 D

5 D

U 3 2

J12B

#11

s n e S

DAMPER

R E T

U 2 3

8 J

RP3

2 4 V D C

+ -

LOW FIRE

C A V 4 2

4-20mA

2 4 V D C

J 1

U19

a m 0

- 4

- B

JP4

0 3 U

6 J

U31

U33

CP6

CP5

S U B D

8 2

1 Y

1 2 J

2 J

- B

1 J

T E N

1 J

CAL

1 S P J

NORM

DHW TANK

DAMPER

+-+

SIP1

0 2 J

d a e B . g o

r P

U12

U21

U 2 5

OPTION

Page 41

Page 42

WIRING CONNECTIONS HeatNet Control REV 1.38-1

Figure 35

Common System Damper Wiring

MEMBER BOILER 2

Connection if Member

boiler is running as

Failsafe

DAMPER

Prove Switch

MEMBER BOILER 1

MASTER BOILER

NOTE: Ensure that the

Combustion Air Damper is enabled on all Boilers for use. SETUP MENU:AUX FUNCTIONS

24 VAC

DAMPER

Page 42

Enable

24 VAC Ret

Mains

DAMPER 24 VAC

Transformer

Connect to 24 VAC

Return on each Boiler

Page 43

WIRING CONNECTIONS HeatNet Control REV 1.38-1

Figure 36

Failsafe Common System Pump Wiring

System Flow Prove

MEMBER BOILER 1

System Flow Prove

120VAC AFTER FLOW SWTICH

System Flow

Prove Switch

120VAC

System Pump Voltage Return

120 Return

System Pump

MASTER BOILER

120VAC

System Pump Voltage Feed

Ph2 Ph3

System Pump

Contactor

Page 43

Page 44

CALIBRATION HeatNet Control REV 1.38-1

Calibration

A detailed startup and walkthrough of the calibration and HNet setup is provided in the Programming Examples manual.

The calibration of the Smith-Series

boiler should only be performed by a licensed technician.

To enter the calibration menus, place the S2 switch on the main control board to the CAL position.

Be sure to set this switch back to NORM when the calibration is complete, otherwise no external control inputs will work (except T1-T2), the display will always indicate CALIBRATE and some of the runtime temperatures will not be displayed.

The MIN VFD setting, the MAX VFD setting, and the Ignition setting can be adjusted in the calibration displays. The values can be changed while running ONLY IN MINIMUM FIRE (any, but only one of the T inputs closed). Prior to ignition, the values may be changed, but the blower will not operate.

Press the arrow keys until MIN VFD is shown in the display, along with the minimum percentage value at which the boiler is to run at min fire. While in Standby (no call for heat on inputs), the minimum percent may be preset. To set the minimum rate while running, any (1), and only (1) of the (T) inputs must be closed in order to set the boiler to MINIMUM fire. Press the ENTER key for approximately 1 second. The Percentage value will start flashing, indicating that it can be adjusted. Adjust the Minimum value to the desired setting using the arrow keys. The Minimum setting is clamped to its lowest rated setting and cannot be adjusted below this. Once you are done with this setting, press the ENTER key until the value stops flashing. The new setting is now saved.

Page 44

Page 45

COMMUNICATIONS HeatNet Control REV 1.38-1

Log Entry

The Smith HeatNet control contains a log that records the major activity (events) in the operation of the boiler. This activity includes interlock faults, boiler starting and stopping events, power cycles, misc. faults, and types of calls-for-heat (control inputs). Setting the time clock to an accurate time and date is very useful when events are recorded, since the control will time stamp each snapshot. If the system is configured to run with HeatNet, then only the Master boilers SYSTEM TIME needs to be entered. The Master will then set the time on all Member boilers.

The log is primarily used as a troubleshooting and diagnostic tool, but may be used as a performance tool to view run time cycles. Refer to the Control Pro Software on the Smith website:

An event in time of the boiler’s state is presented via multiple screens. Each screen event can be stepped through using the arrow keys.

The top line displays the time and date the event occurred. In the top right corner, the event # is displayed so that easy indexing can be done using the arrow keys. The second line displays the Water temperature of the boiler’s output (supply) and the Setpoint temperature. The third line displays the Outside Air temperature, and the Modulation %. The bottom line is used to record the control state of the boiler.

Figure 37

http://www.Smithboiler.com/

Log Entry Display

The control state is defined as the Boiler(s) that is running, the Circulator Pump state, and the ignition condition (Main Valve, Pilot Valve, Blower, and the Ignition alarm). The # of boilers that are displayed is limited to 7 if the boiler is the MASTER. If boilers #8 and up need to be viewed, the Boiler Control Pro software will need to be used. The Last 2 characters on the fourth line indicate the heating mode the control is in. The modes are:

NC = No Call for Heat HD = Heat Demand (MASTER and Local modulation

control using PID control, MASTER and MEMBER)

RM = Remote Modulation from 4-20ma input HF = High Fire from ALL T-inputs closed or the AA

input

1T = Low Fire from any 1 T-input closed (Low Fire

or High Fire)

2T = Mid Fire from any 2 T-inputs closed (Low fire or

High Fire) OP = Option input Active HT = H-Net Control using the Heat-Link

communications cable

The bottom line is also used to indicate an interlock or limit that has tripped. It may also indicate a sensor that has failed. When this occurs, the normal bottom line in the display is not visible, and the sensor fault is displayed.

For details on messages that appear on the fourth line: See Appendix B.

H2O 1 2 7 °F

Outside Air

Temperature

Boiler 1 On

Boiler 2 On

Boiler 3 On

: 0 5 : 4 2 P

6 5 °F

- - - - - -

Boiler 7

P = Circulator Pump

S = System Pump

D = DHW Pump

M = Main Valve open

Time

Stamp

1 0 / 1 4

SET

MOD%

(Ver 2.x control )

P = Pilot Valve open

Event

1 3

1 4 0 °F

5 7

H HD

H= Honeywell Alarm

B = Blower ON

number

Water Setpoint

Modulation PWM %

NC = No Call for Heat HD = Heat Demand RM = Remote Mod 4-20ma HF,1T, 2T, 3T = T-inputs Fire Rates HT = H-NET Control

Page 45

Page 46

DEFAULT SETTINGS & MENU ITEM DESCRIPTIONS HeatNet Control REV 1.38-1

DEFAULT

DESCRIPTION

PUMP OPTIONS

Default Settings & Menu Item Descriptions — SETUP

VALUE

RANGE

BOILERS

# OF BOILERS 1 (1-16) If operating as a member.

LEAD BOILER # 0 (0-16) # of first boiler to run, determines the fire order in rotation. A

# of first boiler to run, determines the fire order in rotation. A

LEAD BOILER # 0 (0-16)

HEAT BAND

HNT M (M-16)

30 °F (2 -50°F)

0 disables the Lead Boiler function. Firing Mode determines lead.

Differential temp around setpoint used to stage boiler(s) OFF/ON

This line displays the boilers auto detected by H-Net. While M is the Master boiler the numbers are the H-Net address of each boiler from 2–16.

SETPOINTS

LOCAL SETPT

OPERATE LIMIT

LOCAL SETPT

OP LIM BAND

SETPT SOURCE AUTO

160 °F (40-220 °F)

215 °F (45-230 °F)

160 °F (40-220 °F)

20 °F (1-50°F)

AUTO

4-20mA

Local setpoint used to maintain temperature of SETPT SOURCE

When running as a member, boiler shuts off when supply temperature reached. Boiler restarts at lower temp of OP LIM BAND or 10F whichever is lower Local setpoint used to maintain temperature of SETPT SOURCE

Limits external input % when in (OP LIM - OP LIM BAND) AUTO = Local/ System/ WWS Setpoint is used

4-20mA input is mapped to a setpoint.

OUTDOOR AIR RESET

OA RESET OFF Outdoor reset ratio (boiler water temp/outside air temp).

WARM WEATHER SD NO

WWS SETPOINT

SET OA SETPOINTS

WATER TEMP

HIGH OA TEMP

WATER TEMP

LOW OA TEMP

68 °F (40 – 100 °F)

140 °F (60 – 150 °F)

10 °F (-35 – 40 °F)

If set to YES, the boiler /system shuts down when the temperature exceeds the WWS SETPOINT.

Temperature at which boiler shuts down, operation is below this. If boiler is running using either OA RESET or WWS and the OA OVR input is closed the OA RESET slope is overridden and runs at local setpoint until OA OVR input opens.

Boiler water temp setpoint when OA temp is at HIGH OATEMP These four setpoints determine the OA reset slope.

Header/Supply setpoint when OA Temp is at LOW OA TEMP

SYSTEM PUMP

POST PRGE TIME 2 minutes (2-60min)

ALWAYS ENABLED OFF ON/OFF ON = Pump never shuts off.

SUMMER PUMP JOG OFF

OVR ENAB IN WWS OFF ON/OFF

Page 46

ON/OFF

MON-SUN

Time in minutes to keep system circ. pump on after boiler stops

Used with Outdoor Reset, Jogs pump for POST PRGE time when system is in summer shutdown. Jog once a week @12:00 AM.

Priority mode for the system pump while in Warm Weather hutdown. ON: The system pump is allowed to run in WWS when the OR OVR override input is closed. When set to OFF, the system pump will not come on while in WWS with the OR OVR override input closed.

Page 47

DEFAULT SETTINGS & MENU ITEM DESCRIPTIONS HeatNet Control REV 1.38-1

NIGHT SETBACK

OPTIONS

LOG/RUNTIME

LOCAL PUMP

DELTA TEMP ENAB OFF

DELTA TEMP 10 °F

POST PRGE TIME 2 minutes (1-60min) Time in minutes to keep local circ. pump on after boiler stops

ALWAYS ENABLED OFF Pump never shuts off.

PUMP/VALVE

OPTIONS

MASTER

PUMP/VALVE

REMAINS ON: OFF ON/OFF

LOCAL PUMP VFD OFF ON/OFF

FLOW PROVE 10s 10-240 sec

SETBACK ENTRY 1 (1 – 4) Four setbacks to adjust setpoint during a time period

ENTRY IS OFF Enable or disable the use of this setback SETBACK

START DAY MON Day of the week to begin setback or a day range

TIME 12:00AM Time to begin setback

END DAY MON Day of the week to end the setback or a day range

TIME 12:00AM Time of the day to end the setback

20 °F (0 – 50 °F)

(2 - 50°F)

ON: Use Delta temperature to shut pump off when temperature across boiler is less than DELTA TEMP setting.

ON: The master boiler will keep its pump/valve on when no boilers are running. Prevents deadheading the system flow.

ON: Outputs a 0-10VDC or 4-20mA signal from J4 pins 1 & 5 that is proportional to the fire rate of the boiler. Connect to a VFDcontrolling a Local pump.

This is an adjustable flow proving time to allow slower valves to open before proving flow.

Temporarily subtracts this temp from the setpoint

TEMP SCALE

KEY CLICK ON Beeps when a key is pressed

SKIP PASSWORD ON Disables the Password

BRIGHTNESS 50% (25, 50,75,100)

RUN HOURS

DATA LOG ENTRY Displays the current entry in the data log

SIZE Displays the current size of the log in entries

BOILER CYCLES

(F or C) Fahrenheit scale is default

Four levels of display brightness, lower for longer life of the display

Displays runtime hours. Total time the main valve has been open.

Displays completed boiler cycles. Incremented when the main valve turns OFF after it has been ON. Does not include attempts to light.

Page 47

Page 48

DEFAULT SETTINGS & MENU ITEM DESCRIPTIONS HeatNet Control REV 1.38-1

AUX FUNCTIONS

COMBUST AIR

DAMPER

The LINKED/COMMON setting allows one common damper to be used and controlled by the Master Boiler. All Member boilers must

IN USE? YES

LINKED/COMMON

INDEPENDENT

have their damper prove inputs wired as per

Reference source not found., Error! Reference source not found.

Section: INDEPENDENT: Individual dampers are in controlled by their respective boiler. If set to YES, then OUTPUT RELAY K5 can be used to control a combustion air damper. The Master can control a common system damper or an individual damper. Members control their respective damper independent of the Master. Relay K5 is used to enable the combustion air damper. See

Error! Reference source not found., Error! Reference source not found.

Needs to Prove the damper is open. There are (2) inputs that may be used for the Combustion Air

INPUT:

PROOF TIME 2:00 (0 – 4min)

ALARM SILENCE

ALARM SILENCE IN

USE?

INPUT = J10B SPARE 2

FAILSAFE MODES

RUN IN LOCAL IF:

H-NET COMM LOST

LOW TEMP OFF

TEMP < 40F

J10B

DAMPER

YES

OFF

40 °F 35-200 °F

Damper. The first is located at J10B terminals 1 and 2 (legacy compatibility). The second input is located at J12B terminals 7 and 8.

This is the proving time in minutes for the combustion air damper prove switch. It is sensed at SPARE 1 on J10B or J12B Pin 7. If J10B is used (legacy), Sensor #5 must be set to ON/OFF in the sensors menu in order to detect the prove switch being made. If the damper faults, a retry will occur every 10 minutes in attempt to open the damper. If Using J12B in a common damper configuration, wiring is done beginning with the Master boiler. J12B Pins 7,8 are connected to the prove switch of the combustion damper. Pin 8 is supplying 24 VAC and pin 7 is the sense input. A second wire is connected to J12B pin 7 of the Master and the other end connected to the first member boilers J12B pin 7. If another member boiler is present, connect another wire to the J12B Pin 7 terminal of the first member and the other end to the second member boiler J12B pin 7. Continue this method for each additional boiler.

This menu allows the configuration of the Alarm Silence switch. It can be disabled so that the Alarm Silence switch can not silence the alarm until the alarm is cleared; ALARM SILENCE = NO. The default value is to enable the ALARM SILENCE switch. This setting allows the Alarm Switch to be looked at using another input. This input should not be changed, but allows for custom configurations to resolve conflicts.

If this entry is set to ON and the Member boiler does not see any communications coming from the Master boiler, this boiler will run in LOCAL. The boiler will continue to run in LOCAL until communications is re-established or this entry is set to OFF. This entry may be set to one of the temperature sensors: SUPPLY, HEADER, RETURN, or turned OFF (default). If this entry is set to a sensor and the temperature falls below TEMP, the boiler will automatically start and run the water temperature up to the LOCAL Setpoint and then shut OFF.

This is the temperature that the selected sensor must fall below for the boiler to start.

Error!

, page

Error! Bookmark not defined.

. Also see

Optional Features: Auxilliary Function Options

, page

Error! Bookmark not defined.

Page 48

Page 49

DEFAULT SETTINGS & MENU ITEM DESCRIPTIONS HeatNet Control REV 1.38-1

DEFAULT

DOMESTIC HOT WATER

SYSTEM CLOCK

HEAT EXCHANGER

ALARM TYPE: WARNING

EXCHR DELTA T

LIM-> HALF RATE YES

LOW TEMP HOLD

VALUE

40 °F

130 °F 130 – 160 °F

RANGE DESCRIPTION

This setting determines the way in which the control reacts when the differential temperature across the heat exchanger exceeds the specified maximum differential temperature. The default alarm condition is a WARNING. The WARNING state will allow the boiler to keep functioning and display a warning message and a timestamp in the status screen when the maximum differential temperature is exceeded. If FAULT is selected, the boiler will shut down and act as if an interlock has tripped. After the Delta T has dropped by 10F the boiler will restart if the demand is still present. This is the maximum differential temperature the heat

per Boiler

exchanger can see before the ALARM TYPE is applied. This value can not be changed and is defined for each boiler size. Limit to Half Rate: When set to YES, and the maximum differential temperature (delta T) has been exceeded, the fire rate called for is cut in half. In other words: if we are calling for 80% modulation and have exceeded the delta T, the boiler will only fire at 40%. The delta T needs to drop 10F below the maximum delta T to reset this limit. The message “ ½ INPUT” will be displayed on a member boiler and a Master Boiler will display the Modulation % for the system even though it is running at ½ of this rate. This method helps protect the heat exchanger from damage due to excessive delta T’s. If this Master boiler is running

The boiler will be held in low fire until the return temperature exceeds the set value. The default is 130F, but can be increased to 160F

DHW BOILER? NO

DHW SETPOINT

DHW DIFF

USE SENSOR? NO

DHW PRIORITY NO

POST PURGE 120s 0-600 secs

DHW MASTER? NO

TIME

DAY OF WEEK

MONTH

DAY

YEAR

PRESS SEL TO SAVE

160 °F 40 – 200 °F

5 °F 1- 30 °F

Setting this value to YES enables the Boiler/System for DHW operation. DHW settings are only looked at if set to YES. Setpoint that the boiler/system will target when a call for DHW. DHW SETPOINT – DHW DIFF : if DHW water temperature is less than this temperature, the Boiler/System will enter DHW Heating mode. Once the DHW SETPOINT is reached, DHW mode is exited. If this entry is set to YES, the DHW 10k Sensor is looked to for controlling DHW water temperature. If set to NO, A thermostat is used. If the DHW PRIORITY is set to YES, then when there is a call for DHW, the system pump shuts off. If NO, the system pump stays on. This is the time that the DHW relay remains on after the DHW call ends. This parameter can only be used if USE SENSOR? is set to YES, and there is NO Header sensor Present.. If set to YES, this boiler becomes the DHW Master Boiler and will use HeatNet to control member boilers based on the DHW Sensor, DHW SETPOINT, and DHW DIFF. If set to NO, only this boiler will run in DHW mode.

This time needs to be entered at first turn-on and inthe event that power has been lost for more than 3 days. The time is only required for an accurate log entry time-stamp and fault time stamp.

The SEL key must be pressed after all time values have been entered to save all time values at once.

Page 49

Page 50

DEFAULT SETTINGS & MENU ITEM DESCRIPTIONS HeatNet Control REV 1.38-1

DISTRIBUTED CTRL

This is no

MODULAR BOILER SET

Default Settings & Menu Item Descriptions — ADVANCED SETUP

CONTROL H-Net Displays method of operation: HeatNet (H-Net)

Auto detected, based on the HEADER sensor.

H-Net MASTER YES

H-NET ADDRESS 255 (2 –16) The local address is the address of a member device.

MODBUS ADDRESS 1 (1 – 247)

ADD BOILER DELAY 10mins (0 – 15min)

SHED BOILER DELAY 2mins (0-15min)

MODULATE DELAY

TIME

MOD MAX – LAST

FIRE

10 secs (0 – 60min)

70% (25 – 100%)

If the HEADER sensor is present and is set to TYPEZ, the Smith-Series control is run as a H-Net MASTER (YES). If the HEADER sensor is not TYPEZ, H-Net MASTER = NO.

The MODBUS address is for communicating with Laptop, PC, or other MODBUS capable device. It is the 2nd communication port reserved for host control.

This is the delay time in 30sec intervals, before starting a new boiler. Boiler #1 is started immediately after a call for heat. If a second boiler needs to start, the ADD BOILER DELAY will need to expire before starting.

This is the delay time in 30 second intervals, before stopping a boiler. A boiler is stopped immediately when the top of the heat band is exceeded. If a second boiler needs to stop, the SHEDBOILER DELAY will need to expire before stopping. This is the time the boiler remains in min-fire before it relinquishes control to the modulation % signal.

This value represents the maximum % of input on the boilers if all the available boilers are not firing. Once all boilers are firing, this clamp is removed and all boilers are allowed to modulate up to 100%. When this value is limiting the input an ‘*’ is displayed and the “INPUT CLAMP” message is displayed in the STATUS screen. This value is derived by: multiplying twice the minimum fire rate of the boiler with the least turndown (2* turndown(20% 5:1, 25% 4:1, 33% 3:1)). In mixed boiler size configurations, more than (2) boilers in a system, or when “bumps” in the temperature occur as boilers are added and subtracted, this value may need adjustment. The adjustments will help produce smooth temperature control when each boiler is started and stopped. This method ensures that, once a new boiler starts to fire, and holds its fire rate at the minimum setting, it does not add its BTU output to a boiler already firing at 100%. The boilers can not be fired starting @ 0%, but start at a minimum (example: 20%) and introduce a minimum amount of BTUs into the system. Section: SETUP & OPERATION

Page 50

Page 51

DEFAULT SETTINGS & MENU ITEM DESCRIPTIONS HeatNet Control REV 1.38-1

ADAPTIVE MOD

FIRING MODE

temperature band. It also minimizes temper

If MODulation MODE is set to ADAPTIVE on the Master boiler, the Master lowers the system modulation rate of all currently running boilers before a newly started boiler enters the Main Valve state. Upon entering the Main Valve state of

MOD MODE ADAPTIVE

DROP DOWN ON CALL

DELAY RELEASE 0s

MODE TRUE

MIN RUNTIME 10 (1-255)

MIN OFF TIME 0 (0-10m)

PREDICT START: YES YES/NO

a newly fired boiler, the Master waits the DELAY RELEASE time before allowing the PID to resume modulation control. With MOD MODE set to ORIG KN, The Master boiler keeps firing at the current modulation rate when a new boiler is added and lets the PID adjust modulation rate accordingly. If drop down is set to ON PILOT and MOD MODE = ADAPTIVE, and when a newly added boiler starts, the system waits until it enters its PILOT state before bring the system modulation down. This allows for the system to prepare for the new energy that is to be introduced. If DROP DOWN is set to immediately, the system modulation is lowered as soon as the newly added boiler is called. Once the Main Valve opens on the newly added boiler and the MOD MODE = ADAPTIVE the Master waits this amount of time before releasing the PID to control modulation. This allows for the newly added boiler to accumulate some soak time.

LOFO: Boilers are fired Last On, First Off starting with Lead Boiler FOFO: Boilers are fired First On, First Off TRUE: Boilers are fired based on the runtime they report back to the Master boiler. Boilers with the least runtime are fired first and boilers with the most runtime are stopped first. MIXED: Different types of boilers can be mixed in a system and fired based on (2) Priority sets. Boilers are started and stopped with in the Priority sets based on their runtime hours. When the firing rotation is based on runtime, this value represents the interval in hours of runtime before rotation occurs. Boiler to Boiler. This is the time in minutes that the boiler must remain OFF before it can be fired again. YES: Predicts the boiler restart point in the heating band while the temperature of the boiler is drifting down through the band. The purpose of this is to ensure the temperature remains in the

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DEFAULT SETTINGS & MENU ITEM DESCRIPTIONS HeatNet Control REV 1.38-1

BASE LOAD BOILERS

SENSORS

4–20mA INPUT

This setting works in conjunction with the ADVANCED

BASE LOAD

BOILERS:

0 0-1

(START>MOD,

START >MOD

START<OA T,

START>RET) START>MOD 100% (20–100) The base load relay K8 will close when the Modulation is >%. START<OA T (40–140) The base load relay K8 will close when the OA temp is > T

START>RET (60–150F)

(FIRST,

STOP FIRST

STOP<MOD,

START>OA T,

START>RET)

STOP<MOD 20% (20–100) 20% (20–100) The base load relay K8 will open when the Modulation is <%. STOP>OA T (40–100F) The base load relay K8 will open when the OA temp is > T.

STOP<RET (60–150F)

DELAY TIME 0 (0–60 minutes)

SETUP: SYSTEM:OPTION setting BASE LOAD. Currently only (1) base load boiler is supported using relay K8 on the Version 2.x control.

Used in Conjunction with DELAY TIME.

The base load relay K8 will close when the Return temp is > T.

The base load relay K8 will open when the Return temp is < T. This setting allows a wait time before firing the base load boiler once the start condition is met.

Sensors can only be changed when there is no call for heat. The boiler must be in STANDBY.

SENSOR #

TYPE

CALIBRATE

4mA SETPOINT

20mA SETPOINT

50 °F 50-220 °F

220 °F 50-220 °F

BOILER START 4.11mA 3.71-5.0mA

PRIORITY NORMAL

The first (4) sensor #’s are reserved as: OUTSIDE AIR, water SUPPLY outlet, water RETURN inlet, and system HEADER temperature. If the HEADER sensor is used (TYPEZ), that boiler performs the tasks of the MASTER boiler. If the HEADER sensor is set to NONE, its function is the MEMBER. The remaining (2) sensors perform as user selections and provide functions such as: Combustion Air Proving. There are (4) sensor types: NONE = do not use this sensor TYPEZ = 10k thermistor ON/OFF = 5 volts supplied out to detect a contact/switch closure. Placing a precision 10k (TYPEZ) precision resistor across the sensor input selected allows calibration of the sensor input.

When using 4-20mA setpoint control in SETPOINTS:SETPOINT SOURCE. This is the temperature when a 4ma signal is applied and is tied to the BOILER START mA. The Setpoint will then be mapped from 4mA – 20mA and example default of: 50-220F This is the setpoint temperature when a 20mA signal is applied. This is the current value which will start the boiler. There is a .1mA hysteresis value. So if the Boiler starts at 4.11mA it shuts off a 4.01mA. If the Priority is set to NORMAL, the boiler responds to its HEAT DEMAND inputs in the Priority that is outlined in the Control Methods section. If the PRIORITY is set to HIGHEST, The 4-20ma input responds at the highest Priority level (same as the AA input). This method may be used by an external control to override the HeatNet control and fire the boiler using this external control (external control override). This allows for complex DHW control systems.

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DEFAULT SETTINGS & MENU ITEM DESCRIPTIONS HeatNet Control REV 1.38-1

PASSWORD

COMMUNICATIONS

LOAD DEFAULTS

SYSTEM

Provides a limited access for security, though restoring

AAAAAA

system defaults will reset the password to the value “AAAAAA”

1200, 2400,

BAUD 19200

DATA FORMAT 8E1

SETPOINT TIMER YES

FACTORY CAL?

FACTORY RESET? NO

BOILER TYPE

FIRING PRIORITY: 2 1 or 2

BTU IN 2000,000

CONDENSING YES

OIL DIRECT FIRE NO

LOAD FIRMWARE NO

OPTION: NO OPTION

4800, 9600,

19200, 38400

8E1, 8N1, 8N2, 8O1

NO OPTION DUAL FUEL

BASE LOAD

This is the Baud rate for serial communication from the MODBUS port. Selectable from 1200, 2400, 4800, 9600, 19200, 38400. 8 bits -Even Parity -1 stop bit, valid settings: 8E1, 8N1, 8N2, 8O1 If set to ‘YES”, the setpoint timer is enabled and requires a periodic update of its value to keep from timing out and retuning control to the H-Net control. If set to “NO”, MODBUS always has control and on a loss of MODBUS communications, H-Net does not assume control.

Selecting YES will load just the factory calibration values: MIN VFD, MAX VFD and IGN VFD. Selecting YES will load all factory defaults except the Calibration values, HeatNet, and Modbus addresses.

There are (2) Priority settings used by the MIXED boiler rotation algorithm. Priority 2 is the default and lowest priority. Priority 1 is the highest priority. A Priority may be assigned to a set of boilers which fires and rotates based on time and is independent of the other Priority set. This is the BTU input rating of the boiler. This value is not used with this version and is displayed only for reference. This defines a boiler as condensing or non-condensing. This value is not used with this version and is displayed only for reference and future applications. Selecting YES will skip the sequence and display PRE PURGE until the opens. Answering YES deletes the existing Firmware and allows a firmware update. When set to DUAL FUEL, input T3/ RESERVED, OPTION input is used to control the DUAL FUEL OPTION relay via K8 contacts on J4.2 &.6. When set to NO OPTION the input T3/RESERVED, OPTION relay K8 on J4.2 &.6 is inactive. When set to BASE LOAD, the Option Relay K8 on J4.2 &.6 is used as an enable contact for a base load boiler. The J4.1 &.5 0-10vdc/4-20mA output is used to modulate the base load relay if it is of the modulating type.

PILOT

stage of the ignition

MAIN

valve

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COMMUNICATIONS HeatNet Control REV 1.38-1

Figure 38

Description

Valid

in case of BMS failure. If the setpoint timer

MODBUS Communications

The Smith-Series control can be controlled using Modbus commands to Enable/Disable the boiler/system. A connection to the Console Modbus Port on the Communications board is required. The Master Boiler assumes the role of MEMBER, RTU, 192Kb, 8 bits, Even Parity, 1 stop bit, when connected to a BMS (Building Management System).

The Member Boilers should not be connected to a BMS system other than to view Read Only addresses. Refer to

http://www.smithboiler.com/ website for greater detail on communicating with Modbus, BACnet, or LonWorks protocols.

MODBUS Input/Output Variables (Read/Write)

Address Name Raw Data Type Scale

Heat Demand/Request. Setting the state

40001 HeatDemand 1 bit unsigned ---

40002 SetpointTimer 16 bit unsigned ---

40003 Setpoint 8 bit unsigned 1.0

40004 OAResetEnable 1 bit unsigned --- Enables/Disables outdoor air reset mode.

member of this variable will put the boiler in heating mode.

System Setpoint Timer

is not written, a default timeout value of 60 seconds is assumed.

System Setpoint (see

SetpointTimer

)

Values/Range

0 = no heat demand 1 = heat demand

0 – 65535 seconds

40 - 220 °F

0 = disabled

1 = enabled

40005 OARSetpoint 8 bit unsigned 1.0

40006 OARHighWaterTemp 8 bit unsigned 1.0

40007 OARHighAirTemp 8 bit unsigned 1.0 High outdoor air temperature setpoint. 50 – 90 °F

40008 OARLowWaterTemp

40009 OARLowAirTemp 8 bit signed 1.0 Low outdoor air temperature setpoint. -35 – 40 °F

40010 SetMonth 8 bit unsigned ---

40011 SetDay 8 bit unsigned ---

40012 SetYear 8 bit unsigned ---

Page 54

8 bit unsigned 1.0

Outdoor air reset setpoint. Temperature at which boiler shuts down.

Boiler water temperature setpoint when outdoor air temperature is at the high outdoor air temperature setpoint (OARHiAirTemp).

Header/Supply temperature setpoint when outdoor air temperature is at the low outdoor air temperature setpoint (OARLoAirTemp).

Set real time clock – month (

Set real time clock – day (

Set real time clock – year (

see SetClock

)

40 – 100 °F

60 – 150 °F

70 – 220 °F

0 (January) - 11

)

(December)

1 – 31

0 – 99

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COMMUNICATIONS HeatNet Control REV 1.38-1

Figure 38

Description

Valid

Figure 39

aw Data

MODBUS Input/Output Variables (Read/Write)

Address Name Raw Data Type Scale

40013 SetHour 8 bit unsigned ---

40014 SetMinute 8 bit unsigned ---

40015 SetSecond 8 bit unsigned ---

40016 SetWeekday 8 bit unsigned ---

40017 SetClock 1 bit unsigned ---

Set real time clock – hour (

Set real time clock – minute (

Set real time clock – second (

SetClock

Set real time clock – weekday (

SetClock

Set (write) the real time clock. Do Not Write more than once per minute To write the real time clock, the system variables (SetMonth, SetMonth, SetDay, SetYear, SetHour, SetMinute, SetSecond, SetWeekday) must first be loaded with the correct date and time. Then, a 1 must be written to the state portion of this system variable to write the new date and time to the system clock.

)

see SetClock

see

Values/Range

)

1 (Monday) - 7

0 = no action

1 = set/write the

0 – 23

0 – 59

(Sunday)

clock

MODBUS Input Variables (Read Only)

Address Name

30001 BoilersOn

30002 Modulation

30003 HeaderTemp

30004 SupplyTemp

30005 ReturnTemp

30006 OutsideTemp

30007 Spare1

30008 Spare2

30009 Month

30010 Day

30011 Year

30012 Hour

30013 Minute

30014 Second

30015 Weekday

30016 Boiler01Status1 16 bit --- Boiler (1 – 16) status flags. These See the “BoilerStatus1”

Type

8 bit

unsigned

8 bit

unsigned

16 bit

signed

16 bit

signed

16 bit

signed

16 bit

signed

16 bit

signed

16 bit

signed

8 bit

unsigned

8 bit

unsigned

8 bit

unsigned

8 bit

unsigned

8 bit

unsigned

8 bit

unsigned

8 bit

unsigned

Scale Description Valid Values/Range

The number of boilers currently

--running.

0.01 Current system modulation level. 0 – 100 %

0.01 Header / System temperature. 32 – 250 °F

0.01 Supply temperature. 32 – 250 °F

0.01 Return temperature. 32 – 250 °F

0.01 Outside air temperature. -40 – 250 °F

--- Raw A/D value from spare 1 input. -32768 to 32767

--- Raw A/D value from spare 2 input. -32768 to 32767

--- Real time clock month.

--- Real time clock day. 1 – 31

--- Real time clock year. 0 – 99

--- Real time clock hour. 0 – 23

--- Real time clock minute. 0 – 59

--Real time clock second. 0 – 59

--Real time clock weekday. 1 (Monday) – 7 (Sunday)

0 – 16

0 (January) - 11

(December)

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COMMUNICATIONS HeatNet Control REV 1.38-1

Figure 39

aw Data

MODBUS Input Variables (Read Only)

Address Name

30017 Boiler01Status2 unsigned bits indicate the state of the 30018 Boiler02Status1 30019 Boiler02Status2 30020 Boiler03Status1 30021 Boiler03Status2 30022 Boiler04Status1 30023 Boiler04Status2 30024 Boiler05Status1 30025 Boiler05Status2 30026 Boiler06Status1 30027 Boiler06Status2 30028 Boiler07Status1 30029 Boiler07Status2 30030 Boiler08Status1 30031 Boiler08Status2 30032 Boiler09Status1 30033 Boiler09Status2 30034 Boiler10Status1 30035 Boiler10Status2 30036 Boiler11Status1 30037 Boiler11Status2 30038 Boiler12Status1 30039 Boiler12Status2 30040 Boiler13Status1 30041 Boiler13Status2 30042 Boiler14Status1 30043 Boiler14Status2 30044 Boiler15Status1 30045 Boiler15Status2 30046 Boiler16Status1 30047 Boiler16Status2 30048 Boiler01RuntimeHigh16 30049 Boiler01RuntimeLow16 30050 Boiler02RuntimeHigh16 30051 Boiler02RuntimeLow16 30052 Boiler03RuntimeHigh16 30053 Boiler03RuntimeLow16 30054 Boiler04RuntimeHigh16 30055 Boiler04RuntimeLow16 30056 Boiler05RuntimeHigh16 30057 Boiler05RuntimeLow16 30058 Boiler06RuntimeHigh16 30059 Boiler06RuntimeLow16 30060 Boiler07RuntimeHigh16 30061 Boiler07RuntimeLow16 30062 Boiler08RuntimeHigh16 30063 Boiler08RuntimeLow16 30064 Boiler09RuntimeHigh16 30065 Boiler09RuntimeLow16 30066 Boiler10RuntimeHigh16 30067 Boiler10RuntimeLow16 30068 Boiler11RuntimeHigh16 30069 Boiler11RuntimeLow16 30070 Boiler12RuntimeHigh16 30071 Boiler12RuntimeLow16 30072 Boiler13RuntimeHigh16 30073 Boiler13RuntimeLow16 30074 Boiler14RuntimeHigh16

Type

16 bit

unsigned

Scale Description Valid Values/Range

and “BoilerStatus2” Tables 24VAC interlocks, ignition circuit, and various other conditions. See the values column for a list of conditions.

Boiler01 = Master Boiler02 = Member01 … Boiler16 = Member15

---

Boiler (1 – 16) Runtime seconds High (Upper) and Low (Lower) 16 bit counters. To get the actual runtime for any given boiler (##), the high and low 16 bit counters must be combined (concatenated) into a single 32 bit counter as:

Boiler##RuntimeHigh16:Boiler##R untimeLow16

Example Boiler01Runtime = (Boiler01RuntimeHigh16 * 65536) + Boiler01RuntimeLow16

Boiler01 = Master Boiler02 = Member01 … Boiler16 = Member15

0 – 4294967295 seconds

below.

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COMMUNICATIONS HeatNet Control REV 1.38-1

Figure 39

aw Data

MODBUS Input Variables (Read Only)

Address Name

30075 Boiler14RuntimeLow16 30076 Boiler15RuntimeHigh16 30077 Boiler15RuntimeLow16 30078 Boiler16RuntimeHigh16 30079 Boiler16RuntimeLow16 30080 Boiler01Status3 30081 Boiler02Status3 30082 Boiler03Status3 30083 Boiler04Status3 30084 Boiler05Status3 30085 Boiler06Status3 30086 Boiler07Status3 30087 Boiler08Status3 30088 Boiler09Status3 30089 Boiler10Status3 30090 Boiler11Status3 30091 Boiler12Status3 30092 Boiler13Status3 30093 Boiler14Status3 30094 Boiler15Status3 30095 Boiler16Status3 30096 Boiler01SupplyTemp 30097 Boiler02SupplyTemp 30098 Boiler03SupplyTemp 30099 Boiler04SupplyTemp 30100 Boiler05SupplyTemp 30101 Boiler06SupplyTemp 30102 Boiler07SupplyTemp 30103 Boiler08SupplyTemp 30104 Boiler09SupplyTemp 30105 Boiler10SupplyTemp 30106 Boiler11SupplyTemp 30107 Boiler12SupplyTemp 30108 Boiler13SupplyTemp 30109 Boiler14SupplyTemp 30110 Boiler15SupplyTemp 30111 Boiler16SupplyTemp 30112 Boiler01ReturnTemp 30113 Boiler02ReturnTemp 30114 Boiler03ReturnTemp 30115 Boiler04ReturnTemp 30116 Boiler05ReturnTemp 30117 Boiler06ReturnTemp 30118 Boiler07ReturnTemp 30119 Boiler08ReturnTemp 30120 Boiler09ReturnTemp 30121 Boiler10ReturnTemp 30122 Boiler11ReturnTemp 30123 Boiler12ReturnTemp 30124 Boiler13ReturnTemp 30125 Boiler14ReturnTemp 30126 Boiler15ReturnTemp 30127 Boiler16ReturnTemp 30128 Boiler01CyclesHigh16 30129 Boiler01CyclesLow16 30130 Boiler02CyclesHigh16 30131 Boiler02CyclesLow16 30132 Boiler03CyclesHigh16

Type

16 bit

unsigned

16 bit

signed

16 bit

signed

16 bit

unsigned

Scale Description Valid Values/Range

Boiler (1 – 16) stage control input

---

0.01

---

flags. These bits indicate the state of the stage control inputs. See the values column for a list of conditions.

Boiler (1 – 16) supply temperature (if available). See BoilerStatus2 to determine if the sensor is present.

Boiler01 = Master Boiler02 = Member01 … Boiler16 = Member15

Boiler (1 – 16) return temperature (if available). See BoilerStatus2 to determine if the sensor is present.

Boiler01 = Master Boiler02 = Member01 … Boiler16 = Member15

Boiler (1 – 16) Cycles High (Upper) and Low (Lower) 16 bit counters. To get the actual cycle count for any given boiler (##), the high and low 16 bit counters must

See the “BoilerStatus3”

Table below.

32 – 250 °F

0 – 4294967295

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COMMUNICATIONS HeatNet Control REV 1.38-1

Figure 39

aw Data

Figure 40

Bit Description

Valid Values/Range

MODBUS Input Variables (Read Only)

Address Name

30133 Boiler03CyclesLow16 be combined (concatenated) into a 30134 Boiler04CyclesHigh16 30135 Boiler04CyclesLow16 30136 Boiler05CyclesHigh16 30137 Boiler05CyclesLow16 30138 Boiler06CyclesHigh16 30139 Boiler06CyclesLow16 30140 Boiler07CyclesHigh16 30141 Boiler07CyclesLow16 30142 Boiler08CyclesHigh16 30143 Boiler08CyclesLow16 30144 Boiler09CyclesHigh16 30145 Boiler09CyclesLow16 30146 Boiler10CyclesHigh16 30147 Boiler10CyclesLow16 30148 Boiler11CyclesHigh16 30149 Boiler11CyclesLow16 30150 Boiler12CyclesHigh16 30151 Boiler12CyclesLow16 30152 Boiler13CyclesHigh16 30153 Boiler13CyclesLow16 30154 Boiler14CyclesHigh16 30155 Boiler14CyclesLow16 30156 Boiler15CyclesHigh16 30157 Boiler15CyclesLow16 30158 Boiler16CyclesHigh16 30159 Boiler16CyclesLow16

Type

Scale Description Valid Values/Range

single 32 bit counter as:

Boiler##CyclesHigh16:Boiler##Cyc lesLow16

Example Boiler01Cycles = (Boiler01CyclesHigh16 * 65536) + Boiler01CyclesLow16

Boiler01 = Master Boiler02 = Member01 … Boiler16 = Member15

MODBUS — BoilerStatus Flags

0 Pilot Valve 0 = closed, 1 = open 1 Blower Running 0 = off, 1 = running 2 Ignition Alarm 0 = ok, 1 = alarm 3 Valve Alarm 0 = ok, 1 = alarm 4 High Limit 0 = ok, 1 = tripped 5 Air Prove Switch 0 = open, 1 = closed 6 RESERVED (FACTORY) 7 Software Operator 0 = off, 1 = on 8 Header Sensor not Detected 0 = detected, 1 = not detected

9 Supply Sensor not Detected 0 = detected, 1 = not detected 10 Return Sensor not Detected 0 = detected, 1 = not detected 11 Outside Sensor not Detected 0 = detected, 1 = not detected 12 System Pump 0 = off, 1 = on 13 Combustion Air Damper 0 = off, 1 = on 14 Master Boiler 0 = member, 1 = master 15 Boiler Detected (at this address) 0 = not detected, 1 = detected

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COMMUNICATIONS HeatNet Control REV 1.38-1

Figure 41

Bit Description

Valid Values/Range

MODBUS — BoilerStatus2 Flags

0 Disabled 0 = enabled, 1 = disabled

1 Heat Demand 0 = no demand, 1 = demand (1)

2 Alarm 0 = ok, 1 = alarm

3 Failed 0 = ok, 1 = failed

4 Member Error 0 = ok, 1 = error

5 Boiler Running 0 = off, 1 = running

6 Pump Running 0 = off, 1 = running

7 Spare 3 Interlock 0 = open, 1 = closed

8 LWCO Interlock 0 = open, 1 = closed

9 VFD Interlock 0 = open, 1 = closed

10 Gas Prove Interlock 0 = open, 1 = closed

11 Spare 4 Interlock 0 = open, 1 = closed

12 Operator Interlock 0 = open, 1 = closed

13 Water Prove (Flow) Interlock 0 = open, 1 = closed

14 UV Sensor Air Prove Interlock 0 = open, 1 = closed

15 Main Valve 0 = closed, 1 = open

This BoilerStatus2 Heat Demand Flag is a combination of the Heat Demand input and the Modbus Heat Demand (40001).

Page 59

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COMMUNICATIONS HeatNet Control REV 1.38-1

Figure 42

Bit Bit Bit

MODBUS — BoilerStatus3 Flags

0 AA High Fire 0 = off, 1 = on

1 Heat Demand (Local Override) 0 = off, 1 = on (1)

2 4-20ma Remote Enable 0 = off, 1 = on

3 Outdoor Air Reset Override 0 = off, 1 = on

4 T1 0 = off, 1 = on

5 T2 0 = off, 1 = on

6 T3 0 = off, 1 = on

7 T4 0 = off, 1 = on

8 reserved for future use ---

9 reserved for future use ---

10 reserved for future use ---

11 reserved for future use ---

12 reserved for future use ---

13 reserved for future use ---

14 reserved for future use ---

15 reserved for future use ---

This BoilerStatus3 Heat Demand Flag is Heat Demand input. On member boilers, this indicates a “Local Override”.

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TROUBLESHOOTING HeatNet Control REV 1.38-1

Troubleshooting

This section is included as an aide to help troubleshoot problems with the setup and operation of the boiler. See Appendix A for additional fault messages.

Situation: Nothing happens when the power switch is turned on.

1. Check For 120 VAC on the Service connector J1. Verify

the line power is connected as per wiring diagram. The Power switch light (ON - Position) should illuminate if this is wired correctly. If the light does not illuminate on the power switch, ensure that J14 is connected to the main board and the power switch.

2. If the Ignition Control is active, but the front panel display

is inactive check:

a. Cable and cable polarity from the control board to the

display.

b. J14 on control board. 120vac is routed from here to

the transformer. The transformer returns 24vac to power the control.

c. Check for 120vac on the primary of the transformer

and 24vac on the secondary. If one of the 24vac interlocks has been shorted to ground or the 24vac output is low, the transformer may be damaged or a 24vac circuit may be miss-wired.

The H-Net control is equipped with resettable

fuses on the power input circuit. Wiring power incorrectly to the unit will cause these fuses to open. Once the incorrect wiring is corrected, the fuses should reset themselves in less than 5 minutes.

Situation: The display is displaying random characters or the control keeps resetting.

There may exist a grounding problem with the controller or one of the boilers, pumps, contactors or other devices connected to it. If all grounding is correct, there may be an issue with radiated or induced electrical noise (interference). This may be caused by, arcing across a contactor's contacts when starting a pump motor, or a large electrical load. It may also be caused by, the ignition transformer being improperly grounded, or the spark gap set incorrectly.

1. Attempt to identify the noise source:

2. What is the boiler/controller trying to do at the time of the

failure?

3. Is the boiler on the same circuit as the noise source? (the

boiler should have isolated power.)

4. Are shielded sensor wires used? (Ensure the shields are

grounded only at the boiler control end.)

5. Are any sensors or sensor wires located near a

transmitting antenna? (Move sensor)

Situation: There are no heating boilers on.

1. Check the settings for WWS SETPOINT, WARM

WEATHER SHUTDOWN; if the outdoor air temperature is above the WWS SETPOINT and WARM WEATHER SHUTDOWN is set to YES, the circulator pump relay will be locked out and the heating boilers will not fire.

Figure 10

f the water temperature is within the heating band around the setpoint, boilers will not come on. The water temperature must fall below the lower band limit to begin firing boilers.

Situation: You get the error message for the Combustion Air Damper.

1. The prove switch for the combustion air damper is not

closing. Check to make sure the dampers are being controlled by the output relay. Also check to make sure the prove switch is wired and working properly.

2. If you are not using the combustion air damper then it

needs to be disabled in the AUX FUNCTIONS menu.

Situation: Unable to change the # of Boilers in the BOILERS menu.

1. In H-Net method, the Smith-Series control auto-detects

the boilers in the system and adjusts the # of boilers accordingly.

2. Using H-NET, if the # of Boilers is not being adjusted

properly to the actual amount of boilers in the system, check each boiler. There can only be (1) master boiler, but there can be up to 15 member boilers. Currently, a total of 16 boilers in a system.

Page 61

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TROUBLESHOOTING HeatNet Control REV 1.38-1

Situation: The boilers menu only indicates 1 boiler, but there are member boilers connected and the amber light blinks on all of the boilers communication’s jacks.

1. Ensure that the latest version of firmware is installed on

all boilers. All boilers in a system must have the same firmware revision.

2. Ensure the proper termination is set on the Master and the

last Member boiler.

Situation: You get the error message – WATER FLOW SWITCH or WAITING FOR FLOW.

1. If the control does not sense a closed circuit at input

connection, WTR FLW. Check to make sure the circuit for the circulator pump is correct, that the pump is being energized, and that the flow prove switch is working properly.

2. If there is no flow prove switch, the Local Flow interlock

can be disabled in the CONFIGURE INTERLKs menu.

Situation: Only the MASTER boiler Fires, but the system has many boilers and is using H-Net.

1. In order for the MASTER boiler to act as a MASTER, the

header sensor must be set to TYPEZ, and there must be a header sensor present. At power-up, the header sensor is auto detected. If the temperature of the header sensor at power-up is greater than –25 °F and less than 240 °F it is considered a valid sensor. The boiler will default to the MEMBER mode if the temperature is not in this range and can only be run locally or by external inputs.

a. If the LOAD FACTORY DEFAULTS has been used

to restore all the default settings, the header sensor has been set to NONE. This needs to be set as stated in 1, and the header sensor will need to be replaced or the temperature brought into a valid range. A power cycle of the boiler will detect the sensor if it is in the range as stated in 1.).

b. The H-Net needs a communications cable daisy-

chained between boilers. Ensure that a good connection is made on the communications board and that the lights on the dual RJ45 jack flash (roughly twice a second). The MASTER is the only one that should flash with no communications cables plugged in.

Situation: H-Net boilers are detected but then lost and then detected again etc...

1. The H-Net communications cable may be receiving

interference from the blower, ignition, or other form of radiated electrical noise. Termination of the jumpers may not be correct or there is more than one master.

a. Ensure that the termination jumpers are set on the

MASTER boiler and only the LAST MEMBER boiler. All of the other member boilers should have their termination jumpers in the non-terminated position.

b. There may be (2) or more MASTER boilers. Ensure

that only one header sensor is present and connected to the SYS/DHW input. There should be no wires or sensors connected to the SYS/DHW input if the boiler is operating as a member. This input is auto detected and defines the boiler as a MASTER.

c. Ensure the cable to connect the H-Net is of a shielded

or twisted pair type. Shielding of the cable is required.

Situation: I am in CALIBRATE and I cannot fire the boiler to adjust it.

1. Only one, but any one of the T1-T2 inputs can be

used to start the boiler. All other inputs are disabled. This method prevents an external control or Building Management System from trying to control the boiler while it is offline and being calibrated. If the boiler is being used as a staged boiler controlled by an external control, the staged inputs need to be disconnected before CALIBRATION, since more than one of the T inputs may be closed by the external control.

Situation: You have forgotten the password.

1. As a last resort, you can turn the controller off, then

depress and hold the ESC key while turning it back on. This will load the default password “AAAAAA”.

d. Minimize the electrical interference by routing the

communications cable away from electrical noise sources, such as: Motors, ignition controls, contactors etc…

Page 62

Situation: Firmware update program starts to load, but then stops, or does not load at all.

1. Check that the termination shunts J3 and J6 are not in the

termination setting. If they are, remove them temporarily

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TROUBLESHOOTING HeatNet Control REV 1.38-1

while updating. Restore them for proper communication with a building management system.

2. Ensure that the USB driver for your PC/Laptop computer

is properly installed.

3. Disconnect BMS or Protocessor Module if connected.

Situation: All HeatNet Boilers fire at the same time.

1. This is usually caused by the HeatNet addresses on the

Member boilers not being set. If the address on each boiler is not set, then all boilers will have address = 2 by default. When the Master boiler calls to fire boiler #2, all boilers with address #2 will fire. Set each Member boiler to a unique address from 2-16.

2. Check the ADD Boiler delay time to ensure it is at a

reasonable value. A setting of 0 will start all the boilers at the same time.

Situation: The boiler is showing that it is running at 45% and there is no fire in the sight glass.

Limit/Operating Limit Band should not overlap the heating band. This may occur when a building management system is controlling the setpoint and is setting the setpoint in the operating limit band.

3. Example: Setpoint set to 180F (by Building Management)

and the Operating Limit is set to 200F with a 20F Operating Limit Band. When the boiler is trying to deliver 180F to the load it’s supply temperature would be a minimum of 180F. The beginning of the Operating Limit Band (looks at supply temp) would be 200F-20F = 180F. Now, when the Master is trying to maintain setpoint at 180F, the boiler is trying to reduce input beginning at 180F at its supply sensor and as a result, fighting the setpoint. The Operating Limit band needs to be reduced in this case, while taking into account the Heat Band differential.

Situation: The Master boiler sees all of the Member boilers in the system, but does not fire any of the Members.

1. If the Master modulates to 100% without firing a Member

boiler and the Member boilers are seen by the Master (in menu SETUP:BOILERS), then the Member boilers are sending back offline status to the Master.

1. The Boiler always shows it’s called for firing modulation

%. This is not an indication of what the boiler is actually firing at. If the ignition control fails to receive a call to fire (last interlock closed on terminal 6 of the ignition control) the display will indicate the called for %. Check if the ignition control is in standby, if so then the HeatNet control has closed the Start contact on J5..10 (Limits) and is waiting for the Blower relay to close on the ignition control which is monitored on J5.3 of the HeatNet control.

Situation: I can hear the blower ramping up and down and the firing rate is changing, but the display indicates it is running at the same modulation rate.

1. The Boiler always shows it’s called for firing modulation

%. This is not an indication of what the boiler is actually firing at. In this case, the boiler is trying to meet the called for modulation % which is displayed, but is unable to do so. The boiler protects itself by looking at it’s supply water temperature and the temperature is probably in the Operating Limit Band. While in the operating limit band, the HeatNet control limits the input of the boiler. The boiler tries to deliver the most input it can in an attempt to meet the called for modulation % without tripping the operating limit.

2. If the boiler is constantly varying in blower speed and in

the operating limit band there may be not enough flow through the boiler or the Operating Limit/Operating Limit Band may be improperly set. The Operating

a. The Member boilers may have an alarm or error

condition which would be indicated by a blinking boiler # in the Boilers Firing screen.

b. Ensure the HeatNet is set up properly: Amber lights

blink on HeatNet Jacks. Only one Master boiler.

c. If the Member boiler is in Local Mode then it also

would not be called and report unavailable to the Master.

d. If the Local flow switch for the Local pump is wired

to the System flow switch input this would also create an offline condition. The Member needs to detect system flow or have a jumper across that sensor input in order for the Member boiler to report available status. The Local flow prove switch must be wired to the Water Flow interlock sensor input.

Situation: We are trying to use a 0-10VDC control signal, but when we send it 10 VDC only 7 VDC is measured at terminal J10B 6 & 7.

1. The HeatNet control was designed to use a 4-20mA

control input. If a 0-10 VDC control signal is to be used, it must supply at least 20mA. 0-10 VDC control signals are not recommended due to line loss and the ability of the control signal to reject noise. So, if

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TROUBLESHOOTING HeatNet Control REV 1.38-1

using a 0-10 VDC control signal it must be able to supply the 20mA.

Situation: We are using a Building Management System (BMS) to control the boilers. We can write the setpoints,

Situation: We are using a BACnet or LonWorks bridge. We can

but they keep changing back to their “default” values after approximately 60 seconds.

talk to the bridge, but all of the data is zero (0) or invalid.

1. When using a BMS, the setpoint values work in

conjunction with the SETPOINT TIMER. The

This condition usually indicates that the bridge is not communicating with the HeatNet control. When operating properly, the bridge continuously reads data from the boiler on the Modbus port into an internal buffer. When a BACnet or LonWorks read request is received, the buffered values are placed in a BACnet or LonWorks packet and sent. If the bridge has never been able to successfully read data from the control, all data points will have their default value which is typically zero. In this situation, the control will also not respond to write commands; for instance changing the setpoint.

SETPOINT TIMER is a failsafe feature used to help detect that a BMS is no longer working or communicating with the control. The time must be regularly loaded with a predetermined number of seconds (1 – 65535). Every second this value will decremented. If it reaches zero, the local (permanently saved) values for the setpoints will be loaded. The concept is that periodically (or every time a setpoint is written), the BMS must write this value. If the value reaches zero (0), the HeatNet control assumes that the BMS in no longer functional and “safe” operational values for the setpoints will be restored. As an example, if it is decided that the BMS will write the control every 5

1. The control’s MODBUS ADDRESS must be set to one

(1). This is set in the ADVANCED SETUP- >DISTRIBUTED CONTROL menu.

minutes, you may decide to write 600 seconds (10 minutes) to the setpoint timer. If after 10 minutes (5 minutes longer than the normal write interval) the BMS has not written the timer, the saved setpoint values will be

2. The control’s BAUD (rate) must be set to 19200 and the

restored.

DATA FORMAT must be set to 8E1 (8 data bits, even parity, 1 stop bit). On older (legacy) versions of firmware, the DATA FORMAT was called PARITY which must be set to EVEN. These settings are set in the ADVANCED SETUP->COMMUNICATIONS menu.

2. As a convenience, the SETPOINT TIMER is

automatically loaded with 60 seconds (if it has fallen below 60) each time the setpoint is written. If you decide to take advantage of this convenience, you would need to write the setpoint periodically at less than 1 minute

3. Check the termination on the BMS/Modbus port. If the

intervals. control is the first or last device on the Modbus RTU network, it should be terminated. For the short cable runs (for instance when using a BACnet or LonWorks bridge on a Revision 1.x board), the termination should be in, but usually doesn’t matter.

The SETPOINT TIMER failsafe feature can be disabled by writing a zero (0) to the timer. The feature will automatically revert back to the enabled state whenever the control is reset or power cycled. The SETPOINT TIMER failsafe feature can permanently disabled in the ADVANCED SETUP-

4. Check the wiring. The Modbus RTU (RS485)

>COMMUNICATIONS menu.

connections on the HeatNet control are A(+), B(-), and G (ground). Some systems use opposite polarity; A(-), B(+). Always use the polarity to determine the proper connections. A ground wire must always be used and a shielded twisted wire is STRONGLY suggested.

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OPERATION HeatNet Control REV 1.38-1

Smith Series Run Screen

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OPERATION HeatNet Control REV 1.38-1

* Status Information

Whenever an * is displayed on the RUN screen it indicates that there is more information available about the current running conditions. This information can be viewed by going to the *STATUS screen as shown on the previous page. For more information on the parameters discussed here please see the Default Settings & Menu Item Descriptions — SETUP, starting on page 46.

Status information screens

This screen indicates that the boiler’s SUPPLY Temperature has gone above the OPERATOR

LIMIT. This will mainly be seen on member

boilers to show why they are not available to

fire.

This screen indicates that the boiler’s SUPPLY

temperature has risen inside the OPERATOR

LIMIT BAND.

This screen indicates the boiler’s input is being

limited by the MOD-MAX value to optimize

system efficiency. This will only be seen on a

MASTER boiler.

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OPERATION HeatNet Control REV 1.38-1

Status information screens

This screen indicates the control is attempting

to re-initiate the ignition control because the

ignition control did not begin PRE-PURGE. For

more information see CALL SERVICE LOG

entry.

This screen indicates that the boiler’s has

received a heat demand, but it’s MINIMUM

OFF time has not expired.

This Screen indicates that the boiler’s input is

temporarily being limited to optimize the boiler’s

efficiency.

This screen indicates that the boiler is running

in LOCAL MODE because it has lost H-NET

communications with the MASTER, and the

failsafe mode has been activated.

This screen indicates that the boiler is running

In LOCAL MODE because the LOW

TEMPERATURE failsafe mode has been

activated. This particular screen shows that the

SUPPLY sensor was used, HEADER, or

RETURN sensors can also be used for this

failsafe mode.

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OPERATION HeatNet Control REV 1.38-1

Smith Series Menu Tree Version 1.38

Page 68

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OPERATION HeatNet Control REV 1.38-1

Smith Series Advanced Menu Tree Version 1.38

DISTRIBUTED

CTRL

MODULAR BOILER SET

ADAPTIVE MOD FIRING

FIRING MODE BASE LOADING

SENSORS

4-20mA INPUT

MODE

CONTROL H- NET

MASTER

H-NET ADDRESS

H- NET

YES

255

MODBUS ADDRESS

ADD BOILER

DELAY

DELAYSHED BOILER

MODULATE

MAXMOD

DELAY TIME

LAST

FIRE

MOD MODE: ADAPTIVE DROP DOWN: ON PILOT DELAY RELEASE :

MODE MIN RUNTIME: MIN OFFTIME PREDICT START:

BASE LOAD BOILERS: 0 START > MOD STOP FIRST DELAY TIME

BRA

CAL I

TE? NO

TRUE

10 HRs

YES

10mins

ADD DELAY TIME

4 MINUTES

0 SECONDS

SHED DELAY TIME

2 MINUTES 0 SECONDS

MODULATE DELAY TIME

0 MINUTES

10 SECONDS

STOP MOD MAX

% 70

START PRIORITY 1 SET: FIRST STOP PRIORITY 1 SET: LAST

PASSWORD

COMMUNICATIONS

DEFAULTSLOAD

SYSTEM

4mA SETPOINT

20mA SETPOINT

BOILER START

68°F

200°F

4.11mA

PRIORITY NORMAL

CLG

COMMUN I CAT I ONS

BAUD 19200 DATA FORMAT 8E1

SETPOINT TIMER ON

P SSW R

- - - -

- - -

FACT ORY

OADA

- --

CAL?

RESET?

BOILER TYPE

CONFIGURE INTERLKS

LOAD F I RMWARE

OPTION: NO OPTION

APPL I CAT I ON HEAT

BOILER TYPE

NO NOFACTORY

PLACE A

1K OR

CHANNEL

TRIM OHMS

TRIM

FIRING PRIORITY : 2 BTU IN 2000,000 CONDENSING YES

OIL DIRECT FIRE NO

PRECI

1OK RES

VALUE

___

SET!

SI ON

I STOR

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WORKSHEET HeatNet Control REV 1.38-1

2 3 4

° ° °

Worksheet

SETUP MENU BOILERS

# of BOILERS LEAD STAGE HEAT BAND °

SETPOINTS

LOCAL SETPOINT ° OPERATE LIMIT °

OP LIM BAND °

SETPOINT SOURCE

OUTDOOR AIR RESET °

OA RESET WARM WEATHER SD WWS SETPOINT ° SET OA SETPOINTS

WATER TEMP °

HIGH OA TEMP ° WATER TEMP °

LOW OA TEMP °

PUMP OPTIONS

SYSTEM PUMP

POST PURGE TIME ALWAYS ENABLED SUMMER PUMP JOG

LOCAL PUMP

DELTA TEMP ENAB DELTA TEMP ° POST PRGE TIME s ALWAYS ENABLED

PUMP/VALVE OPTION

REMAINS ON: LOCAL PUMP VFD

FLOW PROVE

NIGHT SETBACK

SETBACK ENTRY 1 ENTRY IS SETBACK ° SETBACK TIME

START DAY

TIME

END DAY TIME OPTIONS

TEMP SCALE ° KEY CLICK SKIP PASSWORD BRIGHTNESS %

LOG/ RUNTIME

RUN HOURS DATA LOG ENTRY

SIZE

BOILER CYCLES

AUX FUNCTIONS

COMBUST AIR DAMPER

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WORKSHEET HeatNet Control REV 1.38-1

TYPE:

IN USE?

INPUT:

PROOF TIME

ALARM SILENCE SWITCH

IN USE

INPUT:

FAILSAFE MODES

H-NET COMM LOST

LOW TEMP:

TEMP <

HEAT EXCHANGER

EXCHGR DELTA T 40F

LIM-> HALF RATE

DHW SETPOINT DHW DIFF USE SENSOR? DHW PRIORITY? POST PURGE DHW MASTER?

SYSTEM CLOCK

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WORKSHEET HeatNet Control REV 1.38-1

ADVANCED SETUP DISTRIBUTED CTRL

CONTROL H-Net MASTER H-NET ADDRESS MODBUS ADDRESS

MODULAR BOILER SET

ADD BOILER DELAY SHED BOILER DELAY MODULATE DELAY TIME MOD MAX – LAST FIRE

ADAPTIVE MOD

MOD MODE: DROP DOWN DELAY RELEASE

FIRING MODE

MODE

MIXED

START PRIORITY 1 SET:

STOP PRIORITY 1 SET:

MIN RUNTIME

MIN OFF TIME

PREDICT START BASE LOADING

BASE LOAD BOILERS: START > MOD STOP DELAY TIME

SENSORS

SENSOR # TYPE 4-20mA INPUT 4mA SETPOINT 20mA SETPOINT BOILER START

PRIORITY PASSWORD COMMUNICATIONS

BAUD

DATA FORMAT SETPOINT TIMER SYSTEM

BOILER TYPE

LOAD FIRMWARE

OPTION:

OUTDSIDE SUPPLY R E T U R N H E A D E R DHW 6 7 8

Version:

CALIBRATION SETTINGS

MIN VFD

IGN VFD

MAX VFD

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TEMPERATURE REFERENCE HeatNet Control REV 1.38-1

Thermistor Resistance/Temperature Table

Temp °C Temp °F

-40 -40 336,450 60 140 2,488

-35 -31 242,660 65 149 2,083

-30 -22 176,960 70 158 1,752

-25 -13 130,410 75 167 1,479

-20 -4 97,072 80 176 1,255

-15 5 72,951 85 185 1,070

-10 14 55,326 90 194 915.4

-5 23 43,326 95 203 786.6

0 32 32,650 100 212 678.6

5 41 25,391 105 221 587.6

10 50 19,899 110 230 510.6

15 59 15,711 115 239 445.2

20 68 12,492 120 248 389.6

Resistance

Temp °C Temp °F

Resistance

25 77 10,000 125 257 341.9

30 86 8,057 130 266 301.0

35 95 6,531 135 275 265.8

40 104 5,326 140 284 235.4

45 113 4,368 145 293 209.0

50 122 3,602 150 302 186.1

55 131 2,986

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TEMPERATURE REFERENCE HeatNet Control REV 1.38-1

RTD Stack Sensor Resistance/Temperature Table

Temp °C Temp °F Resistance Temp °C Temp °F Resistance Temp °C Temp °F Resistance

0 32 1,000 182 360 1,693 366 690 2,352

4 40 1,017 188 370 1,714 371 700 2,371

10 50 1,039 193 380 1,734 377 710 2,390

16 60 1,061 199 390 1,754 382 720 2,409

21 70 1,082 204 400 1,775 388 730 2,429

27 80 1,104 210 410 1,795 393 740 2,448

32 90 1,125 216 420 1,816 399 750 2,467

38 100 1,147 221 430 1,836 404 760 2,486

43 110 1,168 227 440 1,856 410 770 2,505

49 120 1,190 232 450 1,876 416 780 2,524

54 130 1,211 238 460 1,897 421 790 2,543

60 140 1,232 243 470 1,917 427 800 2,562

66 150 1,254 249 480 1,937 432 810 2,581

71 160 1,275 254 490 1,957 438 820 2,600

77 170 1,296 260 500 1,977 443 830 2,619

82 180 1,317 266 510 1,997 449 840 2,638

88 190 1,339 271 520 2,017 454 850 2,657

93 200 1,360 277 530 2,037 460 860 2,676

99 210 1,381 282 540 2,057 466 870 2,694

104 220 1,402 288 550 2,077 471 880 2,713

110 230 1,423 293 560 2,097 477 890 2,732

116 240 1,444 299 570 2,117 482 900 2,750

121 250 1,465 304 580 2,136 488 910 2,769

127 260 1,486 310 590 2,156 493 920 2,788

132 270 1,507 316 600 2,176 499 930 2,806

138 280 1,528 321 610 2,195 504 940 2,825

143 290 1,548 327 620 2,215 510 950 2,843

149 300 1,569 332 630 2,235 516 960 2,861

154 310 1,590 338 640 2,254 521 970 2,880

160 320 1,611 343 650 2,274 527 980 2,898

166 330 1,631 349 660 2,293 532 990 2,917

171 340 1,652 354 670 2,313 538 1,000 2,935

177 350 1,672 360 680 2,332

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APPENDIX A HeatNet Control REV 1.38-1

*Status Screen Fault Display

There are numerous interlock switches and software limits that are detected. Each of these, when tripped will produce a display message, an audible beeping, and an alarm relay closure. The fault is displayed first, then after a second, the time the fault occurred is displayed. This cycle will keep occurring until the fault is cleared.

These faults and interlocks are:

HIGH LIMIT:

When the high limit aquastat trips the following message is displayed:

LOW WATER CUTOFF:

If there is a low water condition reported by the low water cutoff switch this fault is displayed. Check that there is water flow and water in the boiler. There is a reset switch located on the LWCO box. The interlock connection is located on J5B, LWCO.

GAS PRESSURE:

The gas pressure switches (high pressure and low pressure) are connected in series, so if either trip, a fault will be reported here. A reset switch is located on the gas pressure switches. The interlock is located on J15B, GAS PR.

The high limit interlock breaks power to the ignition control (shutting it off) and effectively removes any chance of the gas valve receiving power. The HeatNet series control will remain powered to display the fault, latch the alarm relay/audible beeper, and to access the log. The interlock is located on J5, HIGH LIMIT. Ensure power is present on the input to the High Limit Control.

SPARE 4:

This is a reserved interlock input that is user defined. The interlock is located on J5B, SPARE 4.

SYSTEM WATER FLOW:

Once the HeatNet series boiler receives a call for heat, it closes the system circulator pump relay. It then waits 10 seconds or more (adjustable) to prove flow. If there is no flow, the flow switch alarm will be set. Every 10 seconds the circulator pump relay will cycle ON for 10 seconds and then OFF for 10 seconds to try and establish flow. The interlock connection is located on J5B, SYSTEM WTR FLOW.

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APPENDIX A HeatNet Control REV 1.38-1

WTR FLW LOCAL:

Once the HeatNet series boiler receives a call for heat, it closes the LOCAL PUMP/VALVE relay. It then waits 10 seconds or more (adjustable) to prove flow. If there is no flow, the flow switch alarm will be set. Every 10 seconds the circulator pump relay will cycle ON for 10 seconds and then OFF for 10 seconds to try and establish flow. The interlock connection is located on J5B, WTR FLW.

IGNITION CTRL ALARM:

The ignition control alarm is displayed if the ignition control detects a fault. This could be a flame failure, air proving switch, or other fault associated with the ignition control. When this fault occurs, you will need to refer to the ignition control for the reason.

OPEN ******* SENSOR :

If the open sensor fault is displayed, the sensor in the position reported was originally detected, but has since opened. The boiler will shut down on any OPEN sensor except the OUSTSIDE AIR sensor.

SHORTED ******* SENSOR:

If the shorted sensor fault is displayed, the sensor in the position reported was originally detected, but has since shorted. The boiler will shut down on any SHORTED sensor except the OUSTSIDE AIR sensor.

DELTA TEMPERATURE WARNING:

COMBUST AIR DAMPER:

If the combustion air damper has been selected for use (AUX FUNCTIONS), and the proof switch does not make, this fault will be displayed.

When the master boiler receives a call for heat and needs to start a boiler, the DAMPER relay closes on J13. If the combustion air damper does not prove within the proof time specified in the combustion air damper menu, the boiler will not start and then display the fault. A combustion damper fault on a boiler can only be cleared by power cycling.

If the temperature difference across the boiler measured from RETURN water to SUPPLY water exceeds 40F this message will be displayed. This can be set to an alarm condition in the AUX FUNCTIONS menu. High delta temperatures can result in damage to the boiler.

RETURN TEMPERATURE WARNING:

If the RETURN water temperature is less than 130F (condensing) this message will be displayed. Return temperatures less than 130F with the boiler running can cause condensation of the flue gases. Condensation of flue gases will damage the heat exchanger. Low return temperatures for an extended period of time can result in damage to the boiler.

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APPENDIX A HeatNet Control REV 1.38-1

AIR SWITCH:

If the IGNITION control closes its blower relay, the control does not see the PILOT relay close within (2) minutes, and the AIR PRESSURE switch is made, this message will be displayed. This alarm protects the boiler from freeze ups being caused by a blower bringing in cold outside air with no fire.

STACK TEMPERATURE:

If the boiler’s stack temperature exceeds 550°F this message will be displayed. If the stack temperature continues to rise above 700 °F the boiler will be held in low fire.

CALL SERVICE:

If the H-Net control closes the last interlock string entering the ignition control and the ignition control never closes its Blower Relay, the H-Net control will wait 2 minutes. The H-Net control will then retry for the duration of the local pump post purge time and then retry the ignition sequence. During this time “retry strt” will be displayed in the status screen. After (5) attempts the H-Net control will lock out and display call service.

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APPENDIX B HeatNet Control REV 1.38-1

Line # 4 Message

Description

Line 4 Log Entries:

The following table lists the messages on line # 4 of the log’s display.

SETBACK IS ACTIVE

SETBACK EXPIRED

NO LOCAL FLOW NO SYSTEM FLOW

COMBUSTION AIR FAIL

SYSTEM RESET -- ----

O: stack overflow, U: Stack Underflow ( both are software faults)

R: Reset Instruction ( Firmware or Default load),

W: Watchdog ( Firmware code ran erroneous code and rebooted), P: Power-ON (Power switch toggled),

B: Brown-out ( Microcontroller saw a voltage less than

4.5 VDC)

OUTDOOR RESET

HIGH DELTA TEMP

If any of the (4) temperature setbacks are active these log entries will be displayed in the log.

If the test for flow fails these log entries will be displayed. The flow proving switches are wired to J11A and J11B.

If the combustion air damper is used and does not prove across J12B DAMPER, this message is displayed.

When the control is reset, this log entry captures the reason the reset occurred.

This log entry indicates that Warm Weather Shutdown is in effect.

This log entry occurs when the temperature across the heat exchanger has been greater than 40 degrees °F.

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APPENDIX B HeatNet Control REV 1.38-1

Line # 4 Message

Description

LOW RETURN TEMP

SHUTDOWN UV TEST

STACK HIGH TEMP

HIGH LIMIT EXCEEDED

IGNITION CTRL ALARM

IRI Alarm

DOMESTIC HOT WATER

LOW WATER CUTOFF VAR FREQ DRIVE GAS PRESSURE SPARE 4 OP LIMIT MECH

START FAILED, RETRY

OP LIMIT REMOTE

OPEN OUTSIDE SENSOR, SUPPLY SENSOR, RETURN SENSOR, HEADER SENSOR, DHW SENSOR

SHORTED OUTSIDE SENSOR, SUPPLY SENSOR, RETURN SENSOR, HEADER SENSOR, DHW SENSOR

If the return temperature is less than 130 degrees °F condensing may be occurring.

After 24 hours of continuous runtime the ignition control module needs to check it’s UV detection circuit. An orderly shutdown and then a restart will occur. This log entry indicates that this has taken place. This is not a fault.

This log entry occurs when the boiler’s stack temperature is greater than 550 °degrees °F.

If the mechanical aguastat trips due to it’s high temperature setting having been exceeded, this log entry will occur.

The ignition control module has faulted while performing an ignition sequence, or while monitoring flame during normal operation.

If the gas valve proving circuit ( if equipped) detects a gas pressure problem.

Indicates a call for DHW heating by either the DHW sensor or an external thermostat.

These log entry faults are result of the interlocks connected to the 24VAC interlock inputs: J11A and J11B. Low Water Cutoff = Low water condition in boiler Var Freq Drive = The Variable Frequency Drive Interlock has tripped Spare 4 = User installed interlock, Op Lim Mech = An external operator (aquastat).

If the H-Net control closes the last interlock string entering the ignition control and the ignition control never closes its Blower Relay, the HNet control will wait 2 minutes. The H-Net control will then retry for the duration of the local pump post purge time and then retry the ignition sequence. During this time “retry strt” will be displayed in the status screen. After (5) attempts the H-Net control will lock out and display call service. The Log will report the retries.

The is the firmware Operating Limit as defined in SETUP:SETPOINTS:OPERATE LIM. When the Supply temperature exceeds this value, this event is logged.

If one of the 10k thermistor sensors was detected to be open or not connected, this fault will be logged.

If one of the 10k thermistor sensors was detected to be shorted this fault will be logged.

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APPENDIX B HeatNet Control REV 1.38-1

Line # 4 Message

Description

AIR SWITCH(BLOWER)

LOST BOILER # FOUND BOILER #

FAIL SAFE H-NET LOST FAIL SAFE LOW TEMP

BASE LOAD BOILER

CALL SERVICE

If a call is made to the ignition control to start and the HeatNet control detects a blower start, but no Pilot within two minutes, the boiler locks out. This log entry indicates that the blower was ON with no flame in the boiler. Freeze up protection.

These log entries indicate that HeatNet has either discovered a boiler or lost a boiler using it’s auto detection algorithm.

If the Fail Safe modes are active, these log entries indicate that they became active for some reason and the boiler had entered Fail Safe mode.

The Base load Boiler Relay K8 is Active if ON Inactive if OFF

If the H-Net control closes the last interlock string connected to the ignition control and the ignition control never closes its Blower Relay, the H-Net control will wait 2 minutes. The H-Net control will then retry for the duration of the local pump post purge time and then retry the ignition sequence. During this time “retry strt” will be displayed in the status screen. After (5) attempts the H-Net control will lock out and display call service.

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Page 82

Smith

260 North Elm Street

Westfield MA 01085