AERCO GF-111-M User Manual

KC series Gas Fired Water Heater
(Massachusetts)
GF-111-M
Operation and Maintenance Manual
AERCO International, Inc. • 159 Paris Ave. • Northvale, New Jersey 07647 • Phone: 201-768-2400 FAX: 201-768-7789
Applicable to Serial Numbers G-02-530 and above
KC Series Gas Fired Water Heating System
Natural Gas or Propane Fired,
Condensing and Forced Draft Hot Water Heater
Patent No. 4,852,524
1,000,000 BTU/HR Input
Printed in U.S.A. REVISED 12/10
KC series Gas Fired Water Heater
(Massachusetts)
GF-111-M
Operation and Maintenance Manual
AERCO International, Inc. • 159 Paris Ave. • Northvale, New Jersey 07647 • Phone: 201-768-2400 FAX: 201-768-7789
Telephone Support
Direct to AERCO Technical Support (8 to 5 pm EST, Monday through Friday)
(800) 526-0288
AERCO International, Inc. 159 Paris Avenue Northvale, NJ 07647-0128
www.aerco.com
© AERCO International, Inc., 2009
The information contained in this operation and maintenance manual is subject to change without notice from AERCO International, Inc.
AERCO makes no warranty of any kind with respect to this material, including but not limited to implied warranties of merchantability and fitness for a particular application. AERCO International is not liable for errors appearing in this manual. Nor for incidental or consequential damages occurring in connection with the furnishing, performance, or use of this material.
Printed in U.S.A. REVISED 12/10
CONTENTS
Para.
Subject
Page
1.1
Warnings & Cautions
1-1
1.2
Emergency Shutdown
1-2
Para.
Subject
Page
1.3
Prolonged Shutdown
1-2
Para.
Subject
Page
2.1
Receiving the Unit
2-1
2.2
Unpacking
2-1
2.3
Installation
2-2
2.4
Gas Supply Piping
2-4
2.5
Electrical Supply
2-5
Para.
Subject
Page
2.6
Field Control W iring
2-6
2.7
Flue Gas Vent Installation
2-9
2.8
Combustion Air
2-9
Para.
Subject
Page
3.1
Introduction
3-1
3.2
Control Panel Description
3-1
3.3
Control Panel Menus
3-3
3.4
Operating Menu
3-4
3.5
Setup Menu
3-4
Para.
Subject
Page
3.6
Configuration Menu
3-6
3.7
Tuning Menu
3-7
3.8
Start Sequence
3-7
3.9
Start/Stop Levels
3-9
Para.
Subject
Page
4-1
Initial Startup Requirements
4-1
4-2
Tools and Instrumentation for Combustion Calibration
4-1
4-3
Combustion Calibration
4-2
Para.
Subject
Page
4-4
Propane Combustion Calibration
4-5
4.5
Unit Reassembly
4-5
4.6
Temperature Control Calibration
4-6
4.7
Over-Temperature Limit Switch Adjustments
4-7
GF-111 THE AERCO KC1000 GAS FIRED DOMESTIC WATER HEATER
Operating & Maintenance Instructions

FOREWARD A

Section 1 – SAFETY PRECAUTIONS 1-1

Section 2 – INSTALLATION PROCEDURES 2-1

Section 3 – CONTROL PANEL OPERATING PROCEDURES 3-1

Section 4 – INITIAL START-UP 4-1

i
CONTENTS
Para.
Subject
Page
5.1
Testing of Safety Devices
5-1
5.2
Low Gas Pressure Fault Test
5-1
5.3
High Gas Pressure Test
5-1
5.4
Low Water Level Fault Test
5-2
5.5
Water Temperature Fault Test
5-2
5.6
Interlock Tests
5-3
5.7
Flame Fault Test
5-3
5.8
Air Flow Fault Test
5-4
Para.
Subject
Page
5.9
SSOV Proof of Closure Switch
5-4
Purge
5.11
Ignition Switch Open During
5-5
5.12
Safety Pressure Relief Valve Test
5-6
Para.
Subject
Page
6.1
Maintenance Schedule
6-1
6.2
Spark Ignitor
6-1
6.3
Flame Detector
6-2
6.4
Combustion Calibration
6-2
6.5
Safety Device Testing
6-2
6.6
BTU Transmitter Pump Lubrication
6-2
Para.
Subject
Page
6.7
BTU Transmitter Assembly
6-3
6.8
Manifold and Exhaust Tubes
6-5
6.9
Heat Exchanger Inspection
6-8
6.10
Condensate Drain Assembly
6-9
Para.
Subject
Page
7.1
Introduction
7-1
Para.
Subject
Page
App
Subject
Page
A
Water Heater Menu Item Descriptions
A-1
B
Startup, Status and Fault Messages
B-1
C
Temperature Sensor Resistance Chart
C-1
D
Water Heater Default Settings
D-1
App
Subject
Page
E
Dimensional and Parts Drawings
E-1
F
Piping Drawings
F-1
G
Wiring Schematics
G-1
H
KC1000 Control Panel Views
H-1

Section 5 – SAFETY DEVICE TESTING PROCEDURES 5-1

5.10 Purge Switch Open During
Ignition
5-5

Section 6 – MAINTENANCE 6-1

Section 7 – TROUBLESHOOTING 7-1

APPENDICES

WARRANTIES W-1

ii
FOREWORD
Foreword
The AERCO KC Water Heating System is a true industry advance that meets the needs of today's energy and environmental concerns. Designed for use in any potable water heating system, it provides constant temperature water, regardless of flow rate. It’s small space requirements and venting capabilities allow maximum installation flexibility. The KC Heater’s load tracking controls modulate over a 20:1 turndown ratio for natural gas units and a 14:1 turndown ratio for propane units to match fluctuating system loads and yield high thermal efficiencies.
With it’s compact design and direct or chimney venting, the KC Water Heating System is adaptable to any installation. Efficiency, reliability and longevity make the KC Water Heating System a true step forward in Water Heating System design.
After prolonged shutdown, it is recommended that the startup procedures in Section 4 and test procedures in Section 5 of this manual be performed to verify system operating parameters. If there is an emergency, turn off the electrical power supply to the KC Heater or close the manual gas valve located before the unit. The installer is to identify the emergency shut-off device. FOR SERVICE OR PARTS, contact your local sales representative or AERCO INTERNATIONAL.
NAME:
ORGANIZATION:
ADDRESS:
TELEPHONE:
INSTALLATION DATE: ____________________________________________________
A
SAFETY PRECAUTIONS
SECTION 1 -- SAFETY PRECAUTIONS

1.1 WARNINGS & CAUTIONS

Installers and operating personnel MUST, at all times, observe all safety regulations. The following warnings and cautions are general and must be given the same attention as specific precautions included in these instructions. In addition to all the requirements included in this AERCO Instruction Manual, the installation of units MUST conform with local building codes, or, in the absence of local codes, ANSI Z223.1 (National Fuel Gas Code Publication No. NFPA-
54) for gas-fired heaters and ANSI/NFPASB for LP gas-fired heaters. Where applicable, the equipment shall be installed in accordance with the current Installation Code for Gas Burning Appliances and Equipment, CGA B149, and applicable Provincial regulations for the class; which should be carefully followed in all cases. Authorities having jurisdiction should be consulted before installations are made.
See pages 1-2 and 1-3 for important information regarding installation of units within the Commonwealth of Massachusetts.
IMPORTANT
This Instruction Manual is an integral part of the product and must be maintained in legible condition. It must be given to the user by the installer and kept in a safe place for future reference.
IMPORTANT
Read the following restrictions prior to installing the water heater:
1. The heater can only be used for applications where the chlorine concentrations Do Not Exceed 4 mg/L which is the Environmental Protection Agency limit for chlorine concentrations in drinking water.
2. Do Not use this heater for a pool heating application.
3. If this heater was ordered with the optional copper-lined, carbon steel shell, items 1 and 2 Do Not Apply. (Contact your local AERCO representative to verify heater shell material.
WARNINGS!
MUST BE OBSERVED TO PREVENT SERIOUS INJURY.
WARNING!
BEFORE ATTEMPTING TO PER­FORM ANY MAINTENANCE ON THE UNIT, SHUT OFF ALL GAS AND ELECTRICAL INPUTS TO THE UNIT.
WARNING
DO NOT USE MATCHES, CANDLES, FLAMES, OR OTHER SOURCES OF IGNITION TO CHECK FOR GAS LEAKS.
WARNING!
THE EXHAUST VENT PIPE OF THE UNIT OPERATES UNDER A POSI­TIVE PRESSURE AND THERE­FORE MUST BE COMPLETELY SEALED TO PREVENT LEAKAGE OF COMBUSTION PRODUCTS INTO LIVING SPACES.
WARNING!
FLUIDS UNDER PRESSURE MAY CAUSE INJURY TO PERSONNEL OR DAMAGE TO EQUIPMENT WHEN RELEASED. BE SURE TO SHUT OFF ALL INCOMING AND OUTGOING WATER SHUTOFF VALVES. CAREFULLY DECREASE ALL TRAPPED PRESSURES TO ZERO BEFORE PERFORMING MAINTENANCE.
WARNING!
ELECTRICAL VOLTAGES OF 120 VAC ARE USED IN THIS EQUIP­MENT. THEREFORE THE COVER ON THE UNIT’S POWER BOX (LOCATED ON THE FRONT RIGHT SIDE OF THE UNIT UNDER THE HOOD AND SHEET METAL SIDE PANEL) MUST BE INSTALLED AT ALL TIMES, EXCEPT DURING MAINTENANCE AND SERVICING.
1-1
SAFETY PRECAUTIONS
MANUAL GAS SHUTOFF VALVE
VALVE OPEN
VALVE CLOSED
CAUTIONS!
Must be observed to prevent equipment damage or loss of operating effectiveness.
CAUTION!
Many soaps used for gas pipe leak testing
must
are corrosive to metals. The piping rinsed thoroughly with clean water after leak checks have been completed.
be
CAUTION!
DO NOT use this heater if any part has been under water. Call a qualified service technician to inspect and replace any part that has been under water.

1.2 EMERGENCY SHUTDOWN

If overheating occurs or the gas supply fails to shut off, close the manual gas shutoff valve (Figure 1-1) located external to the unit.
IMPORTANT
The Installer must identify and indicate the location of the emergency shutdown manual gas valve to operating personnel.

1.3 PROLONGED SHUTDOWN

After prolonged shutdown, it is recommended that the startup procedures in Chapter 4 and the safety device test procedures in Chapter 5 of this manual be performed, to verify all system­operating parameters. If there is an emergency, turn off the electrical power supply to the AERCO heater and close the manual gas valve located upstream the unit. The installer must identify the emergency shut-off device.
Water heater Installations within the Commonwealth of Massachusetts must conform to the
Heater must be installed by a plumber or a gas fitter who is licensed within the Commonwealth of
Prior to unit operation, the complete gas train and all connections must be leak tested using a
The vent termination must be located a minimum of 4 feet above grade level.
If side-wall venting is used, the installation must conform to the following requirements extracted
(a) For all side wall horizontally vented gas fueled equipment installed in every dwelling, building or structure used in whole or in part for residential purposes, including those owned or operated by the Commonwealth and where the side wall exhaust vent termination is less than seven (7) feet above finished grade in the area of the venting, including but not limited to decks and porches, the following requirements shall be satisfied:
Figure 1-1
Manual Gas Shutoff Valve
IMPORTANT – FOR MASSACHUSETTS INSTALLATIONS
following requirements:
Massachusetts.
non-corrosive soap.
from 248 CMR 5.08 (2):
1-2
SAFETY PRECAUTIONS
INSTALLATION OF CARBON MONOXIDE DETECTORS
1. horizontal vented gas fueled equipment, the installing plumber or gasfitter shall observe that a hard wired carbon monoxide detector with an alarm and battery back-up is installed on the floor level where the gas equipment is to be installed. In addition, the installing plumber or gasfitter shall observe that a battery operated or hard wired carbon monoxide detector with an alarm is installed on each additional level of the dwelling, building or structure served by the side wall horizontal vented gas fueled equipment. It shall be the responsibility of the property owner to secure the services of qualified licensed professionals for the installation of hard wired carbon monoxide detectors.
a. In the event that the side wall horizontally vented gas fueled equipment is installed in a crawl space or an attic, the hard wired carbon monoxide detector with alarm and battery back-up may be installed on the next adjacent floor level.
b. In the event that the requirements of this subdivision can not be met at the time of completion of installation, the owner shall have a period of thirty (30) days to comply with the above requirements; provided, however, that during said thirty (30) day period, a battery operated carbon monoxide detector with an alarm shall be installed.
. At the time of installation of the side wall
APPROVED CARBON MONOXIDE DETECTORS.
2. accordance with the above provisions shall comply with NFPA 720 and be ANSI/UL 2034 listed and IAS certified.
3.
SIGNAGE building at a minimum height of eight (8) feet above grade directly in line with the exhaust vent terminal for the horizontally vented gas fueled heating appliance or equipment. The sign shall read, in print size no less than one-half (1/2) inch in size, "GAS VENT DIRECTLY BELOW. KEEP CLEAR OF ALL
OBSTRUCTIONS".
4.
INSPECTION equipment shall not approve the installation unless, upon inspection, the inspector observes carbon monoxide detectors and signage installed in accordance with the provisions of 248 CMR 5.08(2)(a)1 through 4.
(b)
EXEMPTIONS
1. The equipment listed in Chapter 10 entitled "Equipment Not Required To Be Vented" in the most current edition of NFPA 54 as adopted by the Board; and
2. Product Approved side wall horizontally vented gas fueled equipment installed in a room or structure separate from the dwelling, building or structure used in whole or in part for residential purposes.
MANUFACTURER REQUIREMENTS - GAS EQUIPMENT VENTING SYSTEM PROVIDED.
(c) the manufacturer of Product Approved side wall horizontally vented gas equipment provides a venting system design or venting system components with the equipment, the instructions provided by the manufacturer for installation of the equipment and the venting system shall include:
1. Detailed instructions for the installation of the venting system design or the venting system components; and
2. A complete parts list for the venting system design or venting system.
. A metal or plastic identification plate shall be permanently mounted to the exterior of the
. The state or local gas inspector of the side wall horizontally vented gas fueled
: The following equipment is exempt from 248 CMR 5.08(2)(a)1 through 4:
Each carbon monoxide detector as required in
When
MANUFACTURER REQUIREMENTS - GAS EQUIPMENT VENTING SYSTEM NOT PROVIDED.
(d) When the manufacturer of a Product Approved side wall horizontally vented gas fueled equipment does not provide the parts for venting the flue gases, but identifies "special venting systems", the following requirements shall be satisfied by the manufacturer:
1. The referenced "special venting system" instructions shall be included with the appliance or equipment installation instructions; and
1-3
SAFETY PRECAUTIONS
2. The "special venting systems" shall be Product Approved by the Board, and the instructions for that system shall include a parts list and detailed installation instructions.
(e) A copy of all installation instructions for all Product Approved side wall horizontally vented gas fueled equipment, all venting instructions, all parts lists for venting instructions, and/or all venting design instructions shall remain with the appliance or equipment at the completion of the installation.
______________________________________ [End of Extracted Information From 248 CMR 5.08 (2)]
1-4
`SECTION 2 - INSTALLATION

2.1 RECEIVING THE UNIT

Each KC1000 Heater is shipped as a single crated unit. The shipping weight is approximately 1500 lb. and must be moved with the proper rig­ging equipment for safety and to avoid damage. The unit should be completely inspected at the time of receipt from the carrier before the bill of lading is signed. Each unit has Tip-N-Tell indicator on the outside of the crate. This indicates if the unit has been turned on its side.
If the Tip-N-Tell indicator is tripped, do not sign for the shipment. Note the information on the carrier’s paperwork and request a freight claim and inspection by a claims adjuster before proceeding. Any other visual damage to the packaging materials should also be made clear to the delivering carrier.

2.2 UNPACKING

Carefully unpack the unit. Take care not to damage the unit jacket when cutting away packaging materials. A close inspection of the unit should be made to determine if there has been any damage incurred during shipment that was not indicated by the Tip-N-Tell indicator. The freight carrier should be notified immediately
INSTALLATION
if any damage is detected. The following accessories come standard with each unit and are packed separately within the unit’s packing container
Spare Spark Ignitor
Spare Flame Detector
Manual 1-1/4" Gas Shutoff Valve
Drain Valve Assembly
ASME Pressure/Temperature
Relief Valve
Ignitor Removal Tool (One per Site)
Regulator Adjustment Tool (One per
Site
2 Lifting Lugs
Stainless Steel Condensate Cup
Flue Clamps (2 Pieces)
Shell Cap
Wing Nut for Shell Cap
Optional accessories are also separately packed within the unit’s packing container. Standard and optional accessories shipped with the unit should be identified and put in a safe place until they are installed for use.
Figure 2.1 Heater Clearance
2-1
INSTALLATION

2.3 INSTALLATION

The unit must be installed with the prescribed clearances for service as shown in Fig 2.1 These are the by AERCO. Local building codes may require more clearance and take precedence.
KEEP UNIT AREA CLEAR AND FREE FROM COMBUSTIBLE MATERIALS AND FLAMMABLE VAPORS AND LIQUIDS.
MASSACHUSSETTS INSTALLATIONS
For water heater installations within the Commonwealth of Massachusetts, the heater must be installed by a plumber or a gas fitter who is licensed within the Commonwealth. In addition, the installation must comply with all requirements specified in Section 1 (Safety Precautions), pages 1-2 and 1-3.

2.3.1 SETTING THE UNIT

Locate the lifting lugs, shipped with the unit, and attach them to the 5/8” x 11 studs at the top of the unit. Remove the unit from the wooden skid and place in position using a block and tackle or hoist attached to the lifting lugs. (see Fig. 2.2). USE THE LIFTING LUGS TO MOVE THE UNIT.
The KC-1000 is U/L approved for installation on combustible flooring. A 4” to 6" high house­keeping concrete pad is recommended and allows for sufficient drainage of the condensate.
The unit must be secured using only the holes provided in the frame base. Do not use piping to secure the unit in place. See drawing AP-A-576 in Appendix E for the base frame dimensions.
In multiple unit installations, it is important to plan the position of each unit. Sufficient space for piping connections and maintenance require­ments must be given. All piping must include ample provision for expansion.
minimum clearance dimensions required
WARNING !

Figure 2.2

Lifting Lug Location
2.3.2 WATER INLET AND OUTLET PIPING
The locations of the 2" NPT cold water inlet and hot water outlet piping connections are shown in Figure 2.3. Flow rates through the unit are limited to 30 gpm continuous and 40 gpm intermittent.
The heater is shipped with a 2” NPT x 12” long stainless steel flex connector. It is important that this flex connector be installed at the hot water outlet as mentioned in the installation diagrams to ensure compliance with the AERCO warranty. If it is desired to install the flex connector elbowed towards the rear or top of the unit, two additional parts (not supplied with heater) are required. These parts are a 2”NPT x 6” long 304 or 316 stainless nipple and a 2” NPT 304 or 316 stainless elbow. Both of these parts must be capable of withstanding up to 155 psig @ 210°F. These parts may be added between the heater outlet connection and the flex connector. However, if this heater was ordered with the optional copper-lined carbon steel shell (contact your local AERCO Representative to verify), it is not shipped with, and does not require a flex connector.
2-2
INSTALLATION
Shut-off valves and union conections must be installed in the inlet and outlet lines for main­tenance. The use of dielectric unions is recom­mended. Install the piping and accessories as per the following drawings, located in Appendix F of this manual.
SD-A-424 for single units
SD-A-425 for multiple units
SD-A-432 for single units with a stratified
tank
SD-A-434 for multiple units with a stratified storage tank
NOTE:
All piping must be arranged so that it does not interfere with removal of any cover, inhibit service or maintenance, or prevent access between the unit and walls, or another unit.

Figure 2.3

Inlet and Outlet Location
2.3.3 TEST HOSE BIB
A Test Hose Bib connection, upstream of the shut off valve on the hot water outlet, is required for startup and testing. It should be a minimum of 3/4". It cannot be omitted (See Fig. 2.4a)
Figure 2.4a
Hose Bib Location
2.3.4 PRESSURE/TEMPERATURE RELIEF AND DRAIN
VALVE
INSTALLATION
An ASME rated Pressure/Temperature Relief Valve is supplied with each unit. The valve setpoint is 150 psig/210 as shown in Fig. 2.4b. A suitable pipe compound should be used on the threaded connections. Any excess should be wiped off to avoid getting any into the valve body. The relief valve should be piped to within 12 inches of the floor to prevent injury in the event of a discharge. The relief piping must be full size, 1-1/2”, without reduction. No valves, restrictions, or other blockages are allowed in the discharge line. In multiple unit installations the discharge lines
be manifolded together. Each must be
not
must individually run to a suitable discharge location.
A 1” drain valve assembly is furnished with each unit. The assembly should be installed as shown in Figure 2.4b. The drain should be hard piped to a suitable drain.
°
F. Install the relief valve
2.3.5 SYSTEM RECIRCULATION
The system recirculating line ties into the unit at the recirculating tee fitting provided in the drain valve assembly (see Fig. 2.4b). Shut off valves and union connections are recommended for maintenance. Recirculation flow rates must be kept to 8 gpm or less. In a multiple unit installation, each unit must be tied into the system recirculation system.
2-3
INSTALLATION
TEMPERATURE SENSOR
EXHAUST
MANIFOLD
CONDENSATE
DRAIN
BURNER
HOSE CLAMP
1-3/4" O.D. x 8-1 /2 “ LG.
SILICONE HOSE
5/8" O.D. TUBE CONN.
CONDENSATE CUP PLACED ON FLOOR

Figure 2.4b

Pressure/Temperature Relief and Drain
Valve Installation Location
2.3.6 CONDENSATE PIPING
The KC Heater is designed to condense. Therefore, the installation site must include suitable provisions for condensate drainage or collection. A stainless steel condensate cup is separately packed within unit’s shipping container. To install the condensate cup, proceed as follows:
1. Remove the left side panel and only the left
half of the rear cover to provide access to the exhaust manifold and burner (Figure 2.5).
2. Insert the 1-3/4 inch manifold drain hose into
the condensate cup. Allow the cup to rest on the floor directly beneath the manifold drain hole (Figure 2.5).
3. Attach a length of 3/4 inch I.D.polypropylene
tubing to the condensate cup drain tube and route it to a floor drain. . If a floor drain is not available, a condensate pump can be used to remove the condensate to drain. The condensate drain line must be removable for routine maintenance. Therefore, DO NOT hard-pipe.
4. Replace the rear cover and side panel on the
unit.

Figure 2.5

Condensate Drain Assembly Location

2.4 GAS SUPPLY PIPING

AERCO Gas Fired Equipment Gas Components and Supply Design Guide (GF-1030) should be consulted before any gas piping is designed or started.
WARNING !
DO NOT USE MATCHES, CANDLES, FLAMES OR OTHER SOURCES OF IGNITION TO CHECK FOR GAS LEAKS
.
CAUTION !
Many soaps used for gas pipe leak testing are corrosive to metals. The piping must be rinsed thoroughly with clean water after leak checks have been completed
.
NOTE:
All gas piping must be arranged so that it does not interfere with removal of any cover, inhibit service or maintenance, or prevent access between the unit and walls, or another unit
The location of the 1-1/4" inlet gas connection on the right side of the unit is shown in Figure
2.6.
.
2-4
INSTALLATION
W.C. for FM gas train and 8.9” W.C. for IRI gas trains at 1,000,000 BTU/H for natural gas and propane units.
The maximum static inlet pressure to the unit must be no more than 14” W.C.. Minimum gas pressure is 8.5” W.C. for FM gas trains and 8.9” W.C. IRI gas trains when the unit is firing at maximum input. Gas pressure should not exceed 10.5” W.C. at any time when the unit is firing. Proper sizing of the gas supply regulator in delivering the correct gas flow and outlet pressure is mandatory. The gas supply pressure regulator must maintain the gas pressure at a minimum of 8.5” W.C. (FM) or 8.9” W.C. (IRI) when the unit is at maximum BTU input (1,000,000 BTU/HR). The supply gas regulator

Figure 2.6

Gas Supply Regulator and Manual Shut -
Off Valve Location
All pipe should be de-burred and internally cleared of any scale or iron chips prior to installation. No flexible connectors or non­approved gas fittings should be installed. Piping should be supported from floor or walls only and must not be secured to the unit.
A suitable piping compound approved for use with gas should be used sparingly. Any excess must be wiped off to prevent clogging of components.
To avoid damage to the unit when pressure testing gas piping, isolate the unit from the gas supply piping. At no time should there be more than 1 psig maximum to the unit. Bubble test all external piping thoroughly for leaks using a soap and water solution or suitable equivalent. The gas piping must meet all applicable codes.
2.4.1 GAS SUPPLY PRESSURE REGULATOR
A mandatory external, in line, supply gas regulator (supplied by others) should be positioned as shown in Figure 2.6. Union connections should be placed in the proper locations to allow maintenance of the regulator if required.
NOTE:
An individual gas pressure regulator must be installed upstream of each unit. The regulator must regulate gas pressure to 8.5”
must be able to supply sufficient capacity volume, (1000 cfh), to the unit and should have no more than 1" droop from minimum to full fire. The supply gas regulator must also be rated to handle the maximum incoming gas pressure.
When the gas supply pressure will not exceed 14” W.C. a non-lock up, or flow through style regulator, may be used. When supply gas pressure will exceed 14” W.C., a lock up style regulator must be used. The gas supply regulator must be propery vented to outdoors. Consult the local gas utility for exact requirements concerning venting of supply gas regulators.
CAUTION!
A lockup style regulator must be used when gas supply pressure exceeds 14” W.C.
2.4.2 MANUAL GAS SHUTOFF VALVE
A 1-1/4” manual gas shutoff valve is furnished with each unit and should be positioned as shown in Figure 2.6. The valve must be installed upstream of the gas supply regulator in a readily accessible location.
2.4.3 IRI GAS TRAIN KIT
The IRI gas train is an optional gas train required in some areas by code or for insurance pur­poses. The IRI gas train comes pre-assembled and wired from the factory. See Appendix E, Drawing SD-A-606.
The IRI gas train may be ordered pre-assembled or as separate components. If either IRI gas train option is ordered, a complete instructional package, detailing field installation will be included. To obtain a copy of an IRI instructional package prior to the equipment shipping contact your local representative or AERCO.
2-5
INSTALLATION
POWER BOX
BLOWER
SSOV ACTUATOR
FRAME
USE COPPER CONDUCTORS ONLY FOR FIELD WIRING
60 HZ
DISCONNECT POWER BEFORE SERVICING
DANGER: HIGH VOLTAGE
20 AMP
120 VAC,
NEUTRAL
GROUND
LINE
POWER BOX
AERCO INTERNATIONAL INC.
INPUT POWER

2.5 ELECTRICAL SUPPLY

The AERCO Gas Fired Equipment Electrical Power Wiring Guide, (GF-1060), must be consulted in addition to the following material before wiring to the unit is started. AC power connection to the unit are made at the Power Box.This box is located on the front right side of the unit as shown in Figure 2.7.
A means for disconnecting AC power from the unit (such as a service switch) must be installed near the unit for normal operation and maintenance. All electrical connections should be made in accordance with the National Electrical Code and/or with any applicable local codes.
The electrical wiring diagram is shown in Figure
2.8. Conduit should be run from the knockouts in the side of the box in such a manner that it does not interfere with the removal of any sheet metal covers. A flexible electrical connection may be utilized to allow the covers to be easily removed.

Figure 2.7

AC Power Box Location
NOTE:
All electrical conduit and hardware should be installed so that it does not interfere with the removal of any cover, inhibit service or maintenance, or prevent access between the unit and walls or another unit.
2.5.1 ELECTRICAL REQUIREMENTS
Electrical requirements for each unit are 120 VAC, 1 Phase, 60 Hz, 20 Amps from a dedicated electrical circuit. No other devices should be on the same electrical circuit as a KC1000 unit.

Figure 2.8

AC Power Wiring Diagram

2.6 FIELD CONTROL WIRING

Each unit is fully wired from the factory with an internal operating control system. No field control wiring is required for normal operation. However, the KC1000 control system does allow for some control and monitoring features. W iring for these features can be accomplished in the I/O Box behind the left side panel (Figures 2.9 and 2.10). The I/O Box is common to both KC1000 water heaters and boilers. While some of the inputs and outputs are common to both water heaters and boilers, some are not applicable to both. These are noted in the following paragraphs.
CAUTION!
DO NOT make any connections to the I/O Box terminals labeled “NOT USED”. Attempting to do so may cause equipment damage.
2-6
GAS SHUT-OFF VALVE
I/O BOX
BLOWER

Figure 2.9

Input/Output (I/O) Box Location
2.6.1 OUTDOOR AIR SENSOR IN
Not applicable to Water Heaters.
2.6.2 AUX SENSOR IN
The AUX SENSOR IN terminals can be used to add an additional temperature sensor for monitoring purposes. This input is always enabled and is a view only input that can be seen in the operating menu. The sensor must be wired to the AUX SENSOR IN and SENSOR COMMON and must be similar to AERCO BALCO wire sensor P/N 12449. A resistance chart for this sensor can be found in Appendix C.
2.6.3 ANALOG IN
The ANALOG IN + and – terminals are used when an external signal is used to change the setpoint of the water heater when operating in the Remote Setpoint Mode.
Either a 4 to 20 mA / 1 to 5 VDC or a 0 to 20 mA/ 0 to 5 VDC signal may be used to vary the setpoint or valve position. The factory default setting is for 4 to 20 mA / 1 to 5 VDC, however this may be changed to 0 to 20 mA / 0 to 5 VDC using the Configuration Menu described in Section 3. If voltage rather than current is selected as the drive signal, a DIP switch must be set on the CPU Board located inside the Control Box. Contact the AERCO factory for information on setting DIP switches.
All supplied signals must be floating (ungrounded) signals. Connections between the source and the Heater’s I/O Box must be made using twisted shielded pair wire of 18 –22
INSTALLATION
AWG,,such as Belden 9841(see Fig. 2.10). Polarity must be maintained and the shield must be connected only at the source end. It must be left floating (not connected) at the Heater’s I/O Box.
Whether using voltage or current for the drive signal, they are linearly mapped to a 40°F to 240°F setpoint or a 0% to 100% valve position. No scaling for these signals is provided
2.6.4 B.M.S. (PWM) IN
Not applicable to Water Heaters.
2.6.5 SHIELD
The SHIELD terminals are used to terminate any shields used on sensor wires connected to the unit. Shields must only be connected to these terminals.
2.6.6 mA OUT
These terminals provide a 4 to 20 mA output that can be used to monitor setpoint ( to 220°F), outlet temperature ( to 245°F), or valve position (0% to 100%). This function is enabled in the Configuration Menu (Section 3, Table 3.4).

2.6.7 0 – 10V OUT

These terminals provide a 0 to 10 volt output to control the rotational speed of the blower. This function is enabled in the Configuration Menu (Chapter 3, Table 3-4).
2.6.8 RS-485 COMM
These terminals are used for RS-485 MODBUS serial communication between the unit and an external “Master”, such as an Energy Manage­ment System.
2.6.9 EXHAUST SWITCH IN
These terminals permit an external exhaust switch to be connected to the exhaust manifold of the boiler. The exhaust sensor should be a normally open type switch (such as AERCO P/N
123463) that closes (trips) at 500°F.
2.6.10 INTERLOCKS
The unit offers two interlock circuits for interfacing with Energy Management Systems and auxiliary equipment such as pumps or louvers or other accessories. These interlocks are called the Remote Interlock and Delayed Interlock (Fig. 2.10). The wiring terminals for these interlocks are located inside the I/O Box on the left side of the unit. The I/O Box cover contains a wiring diagram which shows the terminal strip locations for these interlocks labeled REMOTE INTL’K IN and DELAYED
2-7
INSTALLATION
mA OUT
RS-485 COMM.
+
-
+
-
ANALOG IN
SENSOR COMMON
OUTDOOR SENSOR IN
REMOTE INTL'K IN
B.M.S. (PWM) IN
SHIELD
+
-
+
-
AUX SENSOR IN
NOT USED
EXHAUST SWITCH IN
DELAYED INTL'K IN
FAULT RELAY 120 VAC, 5A, RES
AUX RELAY 120 VAC, 5A, RES
G
RELAY CONTACTS: 120 VAC, 30 VDC 5 AMPS RESISTIVE
DANGER
120 VAC USED
IN THIS BOX
NOT USED
NOT USED
NC COM NO
NC COM NO
NOT USED
INTL’K IN. Both interlocks, described below, are factory wired in the closed position.
NOTE:
Both the Delayed Interlock and Remote Interlock must be in the closed position to allow the unit to fire.
2.6.10.1 REMOTE INTERLOCK IN
The remote interlock circuit (REMOTE INTL’K IN) is provided to remotely start (enable) and stop (disable) the unit if desired. The circuit is 24 VAC and comes factory pre-wired closed (jumped).
2.6.10.2 DELAYED INTERLOCK
The delayed interlock circuit (DELAYED INTL’K IN) is typically used in conjunction with the auxiliary relay described in paragraph 2.6.11. This interlock circuit is located in the purge section of the start string. It can be connected to the proving device (end switch, flow switch etc.) of an auxiliary piece of equipment started by the unit’s auxiliary relay. The delayed interlock must be closed for the heater to fire. If the delayed interlock is connected to a proving device that requires time to close (make), a time delay (Aux Start On Dly) that holds the start sequence of the unit long enough for a proving switch to make (close) can be programmed. Should the proving
switch not prove within the programmed time frame, the unit will shut down. The Aux Start On Dly can be programmed from 0 to 120 seconds. This option is locate in the Configuration Menu (Section 3).
2.6.11 FAULT RELAY
The fault relay is a single pole double throw (SPDT) relay having a normally open and normally closed set of relay contacts that are rated for 5 amps at 120 VAC and 5 amps at 30 VDC. The relay energizes when any fault condition occurs and remains energized until the fault is cleared and the CLEAR button is depressed. The fault relay connections are shown in Figure 2.10.
2.6.12 AUXILIARY RELAY CONTACTS
Each unit is equipped with a single pole double throw (SPDT) relay that is energized when there is a demand for heat and de-energized after the demand for heat is satisfied. The relay is provided for the control of auxiliary equipment, such as pumps and louvers, or can be used as a unit status indictor (firing or not firing). Its contacts are rated for 120 VAC @ 5 amps. Refer to Figure 2.10 to locate the AUX RELAY terminals for wiring connections.
2-8
Figure 2.10 I/O Box Wiring
INSTALLATION

2.7 FLUE GAS VENT INSTALLATION

AERCO Gas Fired Venting and Combustion Air Guide, GF-1050, must be consulted before any flue or combustion air venting is designed or installed. Suitable, U/L approved, positive pressure, watertight vent materials MUST be used for safety and UL certification. Because the unit is capable of discharging low temperature exhaust gases, the flue must be pitched back towards the unit a minimum of 1/4" per foot to avoid any condensate pooling and to allow for proper drainage.
While there is a positive flue pressure during operation, the combined pressure drop of vent and combustion air systems must not exceed 140 equivalent feet of 0.81” W.C. Fittings as well as pipe lengths must be calculated as part of the equivalent length. For a natural draft installation the draft must not exceed - 0.25” W.C. These factors must be planned into the vent installation. If the maximum allowable equivalent lengths of piping are exceeded, the unit will not operate properly or reliably.

2.8 COMBUSTION AIR

The AERCO Gas-Fired Heater Venting and Combustion Air Guide, GF-1050 MUST be consulted before any flue or inlet air venting is designed or installed. Air supply is a direct requirement of ANSI 223.1, NFPA-54, and local codes. These codes should be consulted before a permanent design is determined.
The combustion air must be free of chlorine, halogenated hydrocarbons or other chemicals that can become hazardous when used in gas­fired equipment. Common sources of these compounds are swimming pools, degreasing compounds, plastic processing, and refrigerants. Whenever the environment contains these types of chemicals, combustion air MUST be supplied from a clean area outdoors for the protection and longevity of the equipment and warranty validation.
The more common methods of combustion air supply are outlined below. For combustion air supply from ducting, consult AERCO GF-1050, Gas Fired Venting and Combustion Air Guide.

2.8.1 COMBUSTION AIR FROM OUTSIDE THE BUILDING

Air supplied from outside the building must be provided through two permanent openings. For each unit these two openings must have a free area of not less than one square inch for each 4000 BTUs input of the equipment or 250 square inches of free area. The free area must take into account restrictions such as louvers and bird screens.

2.8.2 COMBUSTION AIR FROM INSIDE THE BUILDING

When combustion air is provided from within the building, it must be supplied through two perma­nent openings in an interior wall. Each opening must have a free area of not less than one square inch per 1000 BTUH of total input or 1000 square inches of free area. The free area must take into account any restrictions such as louvers.

2.8.3 SEALED COMBUSTION

The unit is UL approved for a 100% sealed combustion application when installed properly. When a sealed combustion air application is installed, the sealed combustion air piping must be deducted from the maximum allowable discharge piping amounts. Each unit must have a minimum 6" diameter connection made to the optional Inlet Air Adapter # GM-18917 available from AERCO. This Adapter bolts directly on to the air inlet of the unit blower. See installation instructions with Adapter. All inlet air ducts must be sealed air tight.
2-9
CONTROL PANEL OPERATING PROCEDURES
3
1
2
7
4
6
10
8
9
5
11
12

SECTION 3 - CONTROL PANEL OPERATING PROCEDURES

3.1. INTRODUCTION

The information in this Section provides a guide to the operation of the KC1000 Water Heater using the Control Panel mounted on the front of the unit. It is imperative that the initial startup of this unit be performed by factory trained personnel. Operation prior to initial startup by factory trained personnel will void the equipment warranty. In addition, the following WARNINGS and CAUTIONS must be observed at all times.
CAUTION:
All initial installation procedures must be satisfied before attempting to start the unit.
WARNING:
ELECTRICAL VOLTAGES IN THIS SYSTEM INCLUDE 120 AND 24 VOLTS AC. IT MUST NOT BE SERVICED OR ACCESSED BY OTHER THAN FACTORY CERTIFIED SERVICE TECHNICIANS.
WARNING:
DO NOT ATTEMPT TO DRY FIRE THE HEATER. STARTING THE UNIT WITHOUT A FULL WATER LEVEL CAN SERIOUSLY DAMAGE THE UNIT AND MAY RESULT IN PERSONNEL INJURY OR PROPERTY DAMAGE. THIS SITUATION WILL VOID ANY WARRANTY.

3.2. CONTROL PANEL DESCRIPTION

The KC1000 Control Panel shown in Figure 3-1 contains all of the controls, indicators and displays necessary to operate, adjust and troubleshoot the KC1000 Water Heater. These operating controls, indicators and displays are listed and described in Table 3-1. Additional information on these items are provided in the individual operating procedures provided in this Section.
Figure 3-1. Control Panel Front View
3-1
CONTROL PANEL OPERATING PROCEDURES
FUNCTION
follows:
COMM
Lights when RS-232 communication is occurring
keypad.
from an Energy Management System
DEMAND
Lights when there is a demand for heat.
Menu Selection
in degrees Fahrenheit or degrees Celsius.
connected to the water heater Control Panel.
5
READY Indicator
Lights when all Pre-Purge conditions have been satisified.
6
ON/OFF Switch
Enables and disables heater operation.
Pressing CLEAR resets the display.
condition occurs. An alarm message will appear in the VFD.
alarms
the Control Panel Menus:
The Menu categories wrap around in the order shown.
category.
Table 3-1. Operating Controls, Indicators and Displays
ITEM
NO.
CONTROL, INDICATOR
OR DISPLAY
1 Four Status LEDs indicate the current operating status as
LED Status Indicators
MANUAL
REMOTE
2 VFD Display Vacuum Fluorescent Display (VFD) consists of 2 lines, each
Lights when the unit is being controlled using the front panel
Lights when the unit is being controlled by an external signal
capable of displaying up to 16 alphanumeric characters. The information displayed includes:
Startup Messages Alarm Messages Operating Status Messages
OUTLET
3
TEMPERATURE
Display
RS-232 Port
4
LOW WATER LEVEL
7
TEST/RESET Switches
FAULT Indicator
8
CLEAR Key
9
10 Consists of 6 keys which provide the following functions for
MENU Keypad
3–Digit, 7–Segment LED display continuously displays the outlet water temperature. The °F or °C LED next to the display lights to indicate whether the displayed temperature is
Port permits a Laptop Computer or External Modem to be
Allow the operator to test the operation of the water level monitor.
Pressing TEST opens the water level probe circuit and simulates a Low Water Level alarm.
Pressing RESET resets the water level monitor circuit.
Red FAULT LED indicator lights when a heater alarm
Turns off the FAULT indicator and clears trhe alarm message if the alarm is no longer valid. Lockout type alarms will be latched and cannot be cleared by simply pressing this key. Troubleshooting may be required to clear these types of
MENU
BACK
Steps through the main menu categories shown in Figure 3-2.
Allows you to go back to the previous menu level without changing any information. Continuously pressing this key will bring you back to the default status display in the VFD. Also, this key allows you to go back to the top of a main menu
3-2
CONTROL PANEL OPERATING PROCEDURES
FUNCTION
pressing the arrow key will increment the selected setting.
setting.
flashing will increment or decrement the displayed setting.
display will stop flashing.
Bargraph
Position in 5% increments from 0 to 100%
Table 3-1. Operating Controls, Indicators and Displays - Continued
ITEM
NO.
CONTROL, INDICATOR
OR DISPLAY
10
(Cont.)
11
12
▲ (Up) Arrow When in one of the main menu categories (Figure 3-2),
pressing this key will select the displayed menu category. If the CHANGE key was pressed and the menu item is flashing,
▼ (Down) Arrow
CHANGE
ENTER
AUTO/MAN Switch
VALVE POSITION
When in one of the main menu categories (Figure 3-2), pressing this key will select the displayed menu category. If the CHANGE key was pressed and the menu item is flashing, pressing the ▼ (Down) arrow key will increment the selected
Permits a setting to be changed (edited). When the CHANGE key is pressed, the displayed menu item will begin to flash. Pressing the or ▼ arrow key when the item is
Saves the modified menu information in memory. The
This switch toggles the water heater between the Automatic and Manual modes of operation. When in the Manual (MAN) mode, the front panel controls are enabled and the MANUAL status LED lights.
When in the Automatic (AUTO) mode, the MANUAL status LED will be off and the front panel controls disabled.
20 segment red LED bargraph continuously shows the Valve

3.3. CONTROL PANEL MENUS

The Control Panel incorporates an extensive menu structure which permits the operator to set up, and configure the unit. The menu structure consists of four major menu categories as shown in Figure 3-2. Each of the menus shown, contain options which permit operating parameters to be viewed or changed. The menus are protected by a password to prevent unauthorized use.
Prior to entering the correct password, the options contained in the Operating, Setup, Configuration and Tuning Menu categories can be viewed. However, with the exception of Internal Setpoint Temperature (Configuration Menu), none of the viewable menu options can be changed.
Once the valid password (159) is entered, the options listed in the Setup, Configuration and Tuning menus can be viewed and changed, if desired.
3.3.1. Menu Processing Procedure
Accessing each menu and option is accom­plished using the Menu Keys shown in Figure 3-
1. Therefore, it is imperative that you be thor­oughly familiar with the following basic steps before attempting to perform specific menu procedures.
1. The Control Panel will normally be in the Operating Menu and the VFD will display the current unit status. Pressing the or arrow key will display the other available data items in the Operating Menu.
2. Press the MENU key. The display will show the Setup Menu which is the next menu category shown in Figure 3-2. This menu contains the Password option which must be entered if other menu options will be changed.
3. Continue pressing the MENU key until the desired menu is displayed.
3-3
CONTROL PANEL OPERATING PROCEDURES
OPERATION
SETUP
CONFIGURATION
TUNING
PASSWORD
4. With the desired menu displayed, press the
or arrow key. The first option in the selected menu will be displayed.
5. Continue to press the or arrow key until
the desired menu option is displayed. Pressing the arrow key will display the available menu options in the Top-Down sequence. Pressing the ▼ arrow key will display the options in the Bottom-Up sequence. The menu options will wrap­around after the first or last available option is reached.
6. To change the value or setting of a displayed menu option, press the CHANGE key. The displayed option will begin to flash. Continue to press the or arrow key for the option to be changed. The available menu option choices will be displayed. The menu option choices do not wrap around.
7. To select and store a changed menu option, press the ENTER key.
NOTE:
The following paragraphs provide brief descriptions of the options contained in each menu. Refer to Appendix A for detailed descriptions of each menu option. Refer to Appendix B for listings and descriptions of displayed startup, status and error messages.

3.4. OPERATING MENU

The Operating Menu displays a number of key operating parameters for the unit as listed in Table 3-2. This menu is “Read-Only” and does not allow personnel to change or adjust any of the displayed items. Since this menu is “Read­Only”, it can be viewed at any time without entering a password. Press the arrow key to display the menu items in the order listed (Top­Down). Pressing the ▼ arrow key will display the menu items in reverse order (Bottom-Up).

3.5. SETUP MENU

The Setup Menu (Table 3-3) permits the operator to set the unit password which is re­quired to change any of the menu options. To prevent unauthorized use, a previously entered password entry will time-out after 1 hour. There­fore, the password must be reentered when required. In addition to permitting password entries, the Setup Menu is also used to enter date and time, language to be used for display messages, units of temperature measurements and entries required for external communication and control of the unit via the RS-232 port. A view-only software version display is also pro­vided to indicate the current Control Box software version.
3-4
Figure 3-2. Menu Structure
CONTROL PANEL OPERATING PROCEDURES
Available Choices or Limits
Menu Item Display
Minimum
Maximum
Default
Status Message
Active Setpoint
40°F
240°F
Aux Temp
30°F
245°F
Outdoor Temp*
-70°F
130°F
Valve Position In
0%
Max Valve
Position
Flame Strength
0%
100%
Run Cycles
0
999,999
Run Hours
0
999,999
Fault Log 0 9
0
Available Choices or Limits
Menu Item Display
Minimum
Maximum
Default
Passsword
0
9999
0
Language
English
English
Time
12:00 am
11:59 pm
Date
01/01/00
12/31/99
Unit of Temp
Fahrenheit
Celsius
Fahrenheit
Comm Address
0
127
0
Software
Ver 0.00
Ver 9.99
NOTE
The Outdoor Temp display item shown with an asterisk in Table 3-2 will not be displayed unless the Outdoor Sensor function has been enabled in the Configuration Menu (Table 3-4).
Table 3-2. Operating Menu
Table 3-3. Setup Menu
Baud Rate 2400

3.6. CONFIGURATION MENU

The Configuration Menu shown in Table 3-4 permits adjustment of the Internal Setpoint (Setpt) temperature regardless of whether the valid password has been entered. Setpt is required for operation in the Constant Setpoint mode. The remaining options in this menu require the valid password to be entered, prior to changing existing entries. This menu contains a number of other configuration settings which
9600 4800 9600
19.2K
may or may not be displayed, depending on the current operating mode setting.
NOTE:
The Configuration Menu settings shown in Table 3-4 are Factory-Set in accordance with the requirements specified for each individual order. Therefore, under normal operating conditions, no changes will be required.
3-5
CONTROL PANEL OPERATING PROCEDURES
Available Choices or Limits
Menu Item Display
Minimum
Maximum
Default
Internal Setpt
Lo Temp Limit
Hi Temp Limit
130°F
Unit Type
Boiler
Water Heater
Boiler
Unit Size
0.5 MBTU, 1.0 MBTU
6.0 MBTU
1.0 MBTU
Water Heater Mode
Constant Setpoint
Remote Setpoint
Constant Setpoint
Remote Signal
4 – 20 mA/1 – 5V
Network
4 – 20 mA,
Outdoor Sensor
Enabled or Disabled
Disabled
System Start Tmp
Enabled)
30°F
100°F
60°F
Setpt Lo Limit
40°F
Setpt Hi Limit
60°F
Setpt Hi Limit
Setpt Lo Limit
240°F
200°F
Temp Hi Limit
40°F
240°F
215°F
Max Valve Position
40%
100%
100%
Pump Delay Timer
0 min
30 min
0 min
Aux Start On Dly
0 sec
120 sec
0 sec
Failsafe Mode
Shutdown or Constant Setpt
Shutdown
mA Output
Setpoint, Outlet Temp, Valve Position Out, Off
Off
Lo Fire Timer
2 sec
120 sec
2 sec
Setpt Limiting
Enabled or Disabled
Disabled
Setpt Limit Band
0°F
10°F
5°F
Table 3-4. Configuration Menu
1.5 MBTU, 2.0 MBTU
3.0 MBTU, 3.5 MBTU
4.0 MBTU, 5.0 MBTU
(If Mode = Remote Setpoint)
(If Outdoor Sensor =
0 -20 mA/0 – 5V
PWM Input (BMS)
1-5V
3-6
CONTROL PANEL OPERATING PROCEDURES
Available Choices or Limits
Menu Item Display
Minimum
Maximum
Default
Min Load Adj
-50°F
50°F
0°F
Max Load Adj
-50°F
50°F
0°F
FFWD Temp
30°F
245°F
Outlet Feedback
On Off
On
Reset Defaults?
Yes
Are You Sure?
No

3.7. TUNING MENU

The Tuning Menu items in Table 3-5 are Factory set for each individual unit.
Table 3-5. Tuning Menu

3.8. START SEQUENCE

When the Control Box ON/OFF switch is set to the ON position, it checks all pre-purge safety switches to ensure they are closed. These switches include:
Safety Shut-Off Valve Proof of Closure (POC) switch
Low Water Level switch
High Water Temperature switch
High Gas Pressure switch
Low Gas Pressure switch
If all of the above switches are closed, the READY light above the ON/OFF switch will light and the unit will be in the Standby mode.
When there is a demand for heat, the following events will occur:
NOTE:
Do not change these menu entries unless specifically requested to do so by Factory­Trained personnel.
No
If any of the Pre-Purge safety device switches are open, the appropriate fault message will be displayed. Also, the appropriate fault messages will be displayed throughout the start sequence, if the required conditions are not observed.
1. The DEMAND LED status indicator will light.
2. The unit checks to ensure that the proof of closure switch in the Safety Shut-Off Valve (SSOV) is closed (Figure 3-3).
Figure 3-3.
Safety Shut-Off Valve
3. With all required safety switches closed, a purge cycle will be initiated and the following events will occur:
3-7
CONTROL PANEL OPERATING PROCEDURES
154
155
AIR/FUEL VALVE
BLOWER PROOF
SWITCH
TO FRAME
HARNESS
(a) Blower relay energizes and turns on
blower.
(b) Air/Fuel Valve rotates to the full-open
purge position and closes purge position switch. The dial on the Air/Fuel Valve (Figure 3-4) will read 100 to indicate that the valve is full-open (100%).
(c) The VALVE POSITION bargraph will
show 100%.
STEPPER
MOTOR
BLOWER
DIAL (DETAIL “A”)
BURNER
Figure 3-5.
Blower Proof Switch
5. Upon completion of the purge cycle, the Control Box initiates an ignition cycle and the following events occur:
100
DETAIL "A"
Figure 3-4.
Air/Fuel Valve In Purge Position
4. Next, the blower proof switch (Figure 3-5) closes and the display will show Purging and indicate the elapsed time of the purge cycle in seconds. The normal (default) time for the purge cycle is 7 seconds.
(a) The Air/Fuel Valve rotates to the low-fire
ignition position and closes the ignition switch. The dial on the Air/Fuel Valve (Figure 3-6) will read between 25 and 35 to indicate that the valve is in the low­fire position.
(b) The igniter relay is activated and pro-
vides ignition spark.
(c) The gas Safety Shut Off Valve (SSOV)
is energized (opened) allowing gas to flow into the Air/Fuel Valve.
6. Up to 7 seconds will be allowed for ignition to be detected. The igniter relay will be turned off one second after flame is detected.
7. After 2 seconds of continuous flame, Flame Proven will be displayed and the flame strength will be indicated. After 5 seconds, the current date and time will be displayed in place of the flame strength.
3-8
CONTROL PANEL OPERATING PROCEDURES
STEPPER
MOTOR
BLOWER
25
DETAIL "A"
DIAL (DETAIL “A”)
Figure 3-6.
Air/Fuel Valve In Ignition Position
8. With the unit firing properly, it will be controlled by the temperature controller cir­cuitry. The VALVE POSITION will be continuously displayed on the front panel bargraph.
9. Once the demand for heat has been
BURNER
satisfied, the Control Box will turn off the gas valve. The blower relay will be deactivated and the Air/Fuel Valve will be closed. Standby will be displayed.

3.9. START/STOP LEVELS

The start and stop levels are the valve position percentages that start and stop the unit, based on load. These levels are Factory preset as follows for natural gas and propane units:
Start Level: 20% (All units)
Stop Level: 13% (Natural Gas)
Stop Level: 16% (Propane)
Normally, these settings should not require adjustment.
Note that the energy input of the boiler is not linearly related to the valve position percentage (Air/Fuel Valve position). Refer to Table 3-6 for the relationship between the energy input and valve position percentage of a unit running on natural gas.
Table 3-6.
Relationship Between Air/Fuel Valve Position and Energy Input of a Unit Running on Natural Gas
Valve Position,
Air/Fuel Valve
Position
(% Open)
Energy Input
(BTU/Hr)
Boiler Energy Input (% of Full Capacity)
0 0 0
10 0 0
13
50,000 5 %
(Stop Level)
20 89,000 9%
30 191,000 19%
40 311.000 31%
50 460,000 46%
60 600,000 60%
70 699,000 70%
80 836,000 84%
90 955,000 96%
100 1,000,000 100%
3-9
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