Weil-McLain BMC, BMC-6X User Manual

BMC and BMC-6X Installation and Operation Manual

Part Number 550-100-072/0408

BMC

AND

BMC-6X

HYDRONIC MODULATING BOILER CONTROL AND EXTENSION

• INSTALLATION AND OPERATION INSTRUCTIONS MANUAL

PWR

OUTPUT RATINGS:

120VAC, 6A RESISTIVE 1A PILOT DUTY, 15A TOTAL FOR ALL CIRCUITS

INPUT RATINGS:

115VAC 60Hz , 30VA MAX

USE COPPER WIRE, CLASS 1 WIRE ONLY.

SYSTEM

CUS

ENCLOSED

ENERGY

MANAGEMENT

EQUIPMENT

LISTED

99RA

SYS

678

CAUTION

: RISK OF ELECTRIC SHOCK More than one disconnect switch may be required to de-energize the equipment before servicing.

CUR / VLT

CUR / VLTBCUR / VLTCCUR / VLT

VLT

GND

Full Modulation Sequencing Control

RUNPROGRAM

VLT

GND

DO NOT APPLY ANY VOLTAGE

OUTDOOR

VLT

TO INPUT TERMINALS

SYSTEM

TEMP

PROVE

------

SHUTDOWN

/TSTAT

/SETBACK

EXTENSION

MODULE

RS-485

BMC

WARNING

This Weil McLain control is strictly an operating control; it should never be used as a primary limit or safety control. All equipment must have its own certified limit and safety controls required by local codes. The installer must verify proper operation and correct any safety problems prior to the installation of this Weil McLain control.

BMC and BMC-6X Installation and Operation Manual

Contents

BMC LAYOUT . . . . . . . . . . . . . . . . 3

BMC OVERVIEW . . . . . . . . . . . . . . 4

Reset Ratio/Outdoor Reset . . . . . . . . . . 5

Make Sure You Have the Right Control . . 6

INITIAL SETUP . . . . . . . . . . . . . . . 6

Selecting the System Features. . . . . . . 6

INSTALLATION . . . . . . . . . . . . . . . 7

Mounting the Enclosure . . . . . . . . . . 7

Install the Sensors . . . . . . . . . . . . . 8

Heating System Sensor (HSS) Installation. . .8

Outdoor Sensor Installation . . . . . . . . . .8

Wiring. . . . . . . . . . . . . . . . . . . . 9

Wiring the Power (Terminals 1, 2) . . . . . . .9

Wiring the Sensors . . . . . . . . . . . . . . .9

Wiring the Shutdown, Tstat, or Setback (Terminals

31, 32) . . . . . . . . . . . . . . . . . . . . . 9

Wiring the Prove (Terminals 29, 30) . . . . . 10

Wiring the Domestic Hot Water Call DHW

(Terminals 29, 30) . . . . . . . . . . . . . . 10

Wiring the System Output (Terminals 3, 4). . 10

Wiring the Boilers . . . . . . . . . . . . . . 10

Wiring to Modulating Motors . . . . . . . . . 11

Connecting to the BMC-6X Panels. . . . . . 11

MENU SEQUENCE . . . . . . . . . . . . . 12

Startup Settings . . . . . . . . . . . . . . 14

Program Change Settings . . . . . . . . . . 14

Startup Sequence . . . . . . . . . . . . . . 14

Sensor Type . . . . . . . . . . . . . . . . . 14

EMS Input Mode (Available In Set point Only) 14

Selecting the Output Type . . . . . . . . . . 14

Selecting the Modulating Mode . . . . . . . 15

Prove/Domestic Hot Water (DHW) . . . . . . 15

Shutdown/Tstat/Setback Mode . . . . . . . . 15

Boost Mode (Not Available with Setback) . . 15

Sensor Fault . . . . . . . . . . . . . . . . . 16

Setting the Control to Factory Defaults. . . 16

Operating Settings . . . . . . . . . . . . . 17

Program Change Settings . . . . . . . . . . 17

Season . . . . . . . . . . . . . . . . . . . . 17

Set Point (Not Adjustable in EMS Mode). . . 17

Reset Ratio. . . . . . . . . . . . . . . . . . 17

Outdoor Cutoff Temperature . . . . . . . . . 18

Offset . . . . . . . . . . . . . . . . . . . . . 18

Minimum Water Temp . . . . . . . . . . . . 18

Maximum Water Temp . . . . . . . . . . . . 18

System Settings . . . . . . . . . . . . . . 19

Gain . . . . . . . . . . . . . . . . . . . . . 19

Lead Boiler Rotation . . . . . . . . . . . . . 19

Purge Delay . . . . . . . . . . . . . . . . . 19

Lag Delay . . . . . . . . . . . . . . . . . . 20

Standby Delay . . . . . . . . . . . . . . . . 20

System Run-On . . . . . . . . . . . . . . . 20

Setback. . . . . . . . . . . . . . . . . . . . 20

Last Stage Hold . . . . . . . . . . . . . . . 21

Day/Night Schedules . . . . . . . . . . . . . 21

Set Time . . . . . . . . . . . . . . . . . . . 22

History . . . . . . . . . . . . . . . . . . . 22

Maintenance . . . . . . . . . . . . . . . . 23

System & Outdoor Sensor Trim . . . . . . . 23

Soft-Off Delay . . . . . . . . . . . . . . . . 23

Output Trim. . . . . . . . . . . . . . . . . . 23

Conﬁguration . . . . . . . . . . . . . . . . . 24

Display . . . . . . . . . . . . . . . . . . . . 24

TROUBLESHOOTING. . . . . . . . . . . . 27

DIRECT HEATING PIPING DIAGRAM . . . 29

DIRECT HEATING WIRING DIAGRAM . . . 30

EXTERNAL 4-20MA SET POINT . . . . . . 31

USING 4-20MA EMS INTERFACE . . . . . 31

SPECIFICATIONS . . . . . . . . . . . . . . 32

BMC Speciﬁcations. . . . . . . . . . . . . 32

BMC-6X Speciﬁcations . . . . . . . . . . . 32

BMC and BMC-6X Installation and Operation Manual

BMC LAYOUT

Program Switch to restrict access to function changes. This switch is covered with Wiring Enclosure.

LED indicates the associated relay status.

OUTPUT RATINGS:

120VAC, 6A RESISTIVE 1A PILOT DUTY, 15A TOTAL FOR ALL CIRCUITS

INPUT RATINGS:

115VAC 60Hz , 30VA MAX

USE COPPER WIRE, CLASS 1 WIRE ONLY.

CUS

ENCLOSED

ENERGY

MANAGEMENT

PWR

EQUIPMENT

LISTED

99RA

SYS

CAUTION: RISK OF ELECTRIC SHOCK

More than one disconnect switch may be required to de-energize the equipment before servicing.

678

SYSTEM

CUR / VLT

CUR / VLTBCUR / VLTCCUR / VLT

VLT

GND

The digital display shows the system status, set point, lead stage <in brackets>, and status of each stage. To view and adjust settings, press the appropriate buttons.

Buttons function is presented on

Bottom Row of display.

BMC

Full Modulation Sequencing Control

------

RUNPROGRAM

VLT

GND

DO NOT APPLY ANY VOLTAGE

OUTDOOR

TEMP

VLT

TO INPUT TERMINALS

SYSTEM

PROVE

TEMP

SHUTDO /TSTAT /SETBACK

EXTENSION

MODULE

RS-485

120VAC Power

System Output controls pumps, valves, or other system components.

Four N.O. Boiler startup relay outputs. Each is wired in series with each boiler's limit circuit.

Four modulation outputs can be 0-5V,

0-10V, 1-5V, 2-10V, or 4-20ma. Go to

Startup Menu to determine the type of

output for each stage.

When connecting Outdoor and System

Sensors, no Polarity is observed.

Prove terminals must be connected

for BMC to operate boilers.

Connect Extension panels to

add additional stages using

a 6 pin phone line only (cable

provided with BMC-6X).

BMC and BMC-6X Installation and Operation Manual

BMC OVERVIEW

SEQUENCES UP TO 4 FULLY MODULATING STAGES.

The BMC is the perfect control whenever multiple fully modulating stages are required for hydronic heating applications. The BMC controls the on/off and the modulation of each stage to maintain precise system set point control.

PID TYPE LOGIC

The BMC’s control algorithms allow it to look at the rate of change in the system. If the system temperature is changing quickly, the BMC will react quickly to adjust the modulating stages’ output. If the system temperature changes slowly, the BMC will make slow and gradual output adjustments. Therefore, the BMC adapts to speciﬁc system requirements and minimizes ﬂuctuations around the set point.

CONTROLS 0-5 V, 0-10 V, 1-5V, 2-10V, OR 4-20 MA MODULATING MOTORS

The BMC is designed to accurately control the output from 0 to 100% of modulation for each of these different types of motors. One BMC can even control a variety of the above different motors.

ONLY ONE SENSOR

When Set Point sensor type is selected, the BMC requires only one sensor located in the common output header of all stages. However, when Reset is selected, an additional Outdoor Sensor is required for Outdoor Reset Ratio input.

DIGITAL DISPLAY OF ALL SYSTEM SETTINGS

The BMC’s alphanumeric digital display names each system parameter in simple English and shows its precise value. The easy to follow menu system allows users to quickly make changes to any system setting without having to learn any specialized codes or keyboard commands.

AUTOMATIC ROTATION AMONG STAGES

Rotating the ﬁrst stage to be activated on a call for output promotes even wear on each stage. The BMC has three modes of rotation: Manual, Last On, or Time. The Time rotates the lead stage every selected time period from every hour to every 60 days.

OUTDOOR RESET

The BMC has a hydronic outdoor temperature reset function. This allows the BMC to change the set point based on outdoor temperature. Furthermore, additional settings have been added to ﬁne tune this operation, like Offset, Minimum, and Maximum Water Temperature and night setback schedule.

STANDBY BOILERS

Each of the BMC stages can be conﬁgured as a Standby boiler with an adjustable Standby delay. A boiler can be used as a backup during extended large demand periods.

SYSTEM OUTPUT

In Set Point mode, this output can be used to activate a system pump, combustion air damper, or perform any other function that is required when any stage is active. In Outdoor Reset mode, the System Output will activate whenever the outdoor temperature is below the Outdoor Cutoff setting. A System Prove input checks the status of components activated by the System output before stages can be activated.

STAGING (NORMAL) OR PARALLEL MODULATION

The BMC can stage boilers as needed. That will allow it to increase the modulation on the lead boiler. When the lead boiler reaches its modulation start point adjustment and does not satisfy the load, the BMC will start the next boiler and so on... Moreover, the BMC allows for a parallel mode that can modulate several boilers together as a one large boiler. This mode is useful for boilers with lower water content, which are usually more efﬁcient at lower ﬁring points.

ADD UP TO 16 BOILER STAGE (OPTIONAL)

As a stand-alone, the BMC is designed to control four modulating boilers. However, it has the capability of expanding its control to two extension panels each with six boiler stages. Thus, the BMC can control a total of up to 16 boiler stages.

BMC and BMC-6X Installation and Operation Manual

UNDERSTANDING OPERATION CONCEPT

1:3 1:2 1:1.5

The BMC has multiple operating modes that satisfy most hydronic systems. It can change the System Set Point based on outdoor temperature (Outdoor Reset) or it can modulate its stages to achieve an adjustable ﬁxed Set Point.

In Outdoor Reset, the BMC controls a hot water heating system to provide a building with comfortable and even heat levels. The BMC varies the temperature of the circulating heating water in response to changes in the outdoor temperature. The heating water temperature is controlled through the modulation of stages.

The BMC also controls the system circulating pump with an adjustable Outdoor Cutoff. When the outdoor temperature is above Outdoor Cutoff, the pump is off and no heating water is circulated through the system. When the outdoor temperature drops below the Outdoor Cutoff, the system pump relay is activated and the heating water circulates through the system. The temperature of the heating water is controlled by the Reset Ratio, Water Offset, and changes with Outdoor temperature.

RESET RATIO/OUTDOOR RESET

When a building is being heated, heat escapes through the walls, doors, and windows to the colder outside air. The colder the outside temperature, the more heat escapes. If you can input heat into the building at the same rate that it is lost out of the building, then the building temperatures will remain constant. The Reset Ratio is an adjustment that lets you achieve this equilibrium between heat input and heat loss.

The starting point for most systems is the 1.00 (OD):1.00 (SYS) (Outdoor Temperature : Heating Water Temperature) ratio. This means that for every degree the outdoor temperature drops, the temperature of the heating water will increase one degree. The starting point of the curves is adjustable, but comes factory selected at 70

°F Outdoor

Temp. and 100°F Water Temp. For example with a 1.00 (OD):1.00 (SYS) ratio, if the outdoor temperature is 50°F, this means the temperature has fallen 20° from the starting point of 70°F. Therefore, the heating water temperature will increase 20° to 120°F.

Each building has different heat loss characteristics. A very well insulated building will not lose much heat to the outside air, and may need a Reset Ratio of 2.00 (OD):1.00 (SYS) (Outdoor:Water). This means the outdoor temperature would have to drop 2 degrees to increase the water temperature 1 degree. On the other hand, a poorly insulated building with insufﬁcient radiation may need a Reset Ratio of 1.00 (OD):2.00 (SYS). This means that for each degree the outdoor temperature dropped the water temperature will increase 2 degrees. The BMC has a full range of Reset Ratios to match any buildings heat loss characteristics.

A heating curve that relies not only on Outdoor temperature but also on type of radiation will improve heat comfort. The following are suggested initial settings for different types of radiation based on average building insulation and heat loss. The contractor can ﬁne tune these adjustments based on the speciﬁc building need.

With a 0° Offset, the ratio curves begin at 100° Water Temperature.

With a -20° Offset, the ratio curves begin at 80° Water Temperature.

With a +20° Offset, the ratio curves begin at 120° Water Temperature.

220

210

200

190

180

170

160

150

140

130

Water Temperature (in °F)

120

110

100

70 605040 20

Reset Ratio Curves

1:4

30 0 -10

Outdoor Temperature (in °F)

Reset Ratio is Presented as

Outdoor Temp. : Water Temp. R atio

130

120

110

Water Temperature

100

70 405060

Outdoor Temperature

110

100

Water Temperature

70 405060

Outdoor Temperature

150

140

130

Water Temperature

120

100

70 405060

Outdoor Temperature

1:1.25

1:1

1.25:1

1.5:1

2:1

3:1 4:1

10 -20

1:4 1:1

4:1

1:4

-20 Offset

1:4

1:1

4:1

1:1

+20 Offset

4:1

Type of Radiation in Building Reset Ratio Offset

Radiators (Steel & Cast Iron) 1.00 (OD) : 1.00 (SYS) 0˚F

Baseboard (Finned copper tube& Cast Iron) 1.00 (OD) : 1.00 (SYS) 0˚F

Radiant (High Mass/Concrete) 4.00 (OD) : 1.00 (SYS) -10˚F

Radiant (Low Mass/Joists) 2.00 (OD) : 1.00 (SYS) -10˚F

Fan Coils & Air Handlers 1.00 (OD) : 1.00 (SYS) 20˚F

WARNING

When controlling a non condensing boiler directly without the use of a mixing valve, minimum boiler water temperature must be set to boiler manufacturer speciﬁcations. In that case, system temperature must not go below such temperature.

BMC and BMC-6X Installation and Operation Manual

MAKE SURE YOU HAVE THE RIGHT CONTROL

If you need the BCP-8W to do additional tasks that either are not listed or do not know how to set them, contact Weil McLain.

INITIAL SETUP

Setting an Initial Program will ease the conﬁguration of the BMC and will give the opportunity to utilize many of the energy saving features and give more comfortable heat when needed.

The program should consist of the following:

• Selecting the features that your system can utilize,

• Installation: Install the Control, switches and sensors,

• Setting the System Startup,

• Setting the System Settings,

• Setting the Stages

• Adjusting Reset Ratio and Water Offset (In Reset Mode Only)

SELECTING THE SYSTEM FEATURES

The BMC has been designed with Hydronic building heating as the primary purpose. With this in mind, many of the BMC features can be utilized to ease, enhance and improve your system performance. Some of these features are listed in this section.

OUTDOOR RESET OR SET POINT

• The BMC can control the System Temperature either by adjusting the calculated temperature according to the Outdoor Temperature (Outdoor Reset) or by maintaining an adjustable Set Point. The earlier relies on an Outdoor Sensor (supplied with the control) and achieves better fuel savings in addition to better comfort.

NUMBER OF STAGES

• The BMC can be conﬁgured to control up to 4 modulating boilers. It can control up to 16 boiler stages using a maximum of two BMC-6X Panels

MODULATION MODE

• The BMC can stage boilers using one of two methods. Normal Modulation Mode, allows it to increase the modulation of the lead boiler. When the lead boiler reaches its modulation start point adjustment and does not satisfy the load, the BMC will start the next boiler and so on. This mode targets boilers that can run more efﬁcient at higher modulation rates.

• The Parallel Modulation Mode can modulate several boilers together as a one large boiler. This mode is useful for boilers that are more efﬁcient at lower ﬁring points.

MODULATING SIGNAL

• The BMC is designed to accurately control the output from 0 to 100% of modulation for each of these different types of motors. One BMC can even control a variety of the above different modulation motors.

AUTOMATIC ROTATION AMONG BOILERS

• Rotating the ﬁrst burner to be activated on a call for output promotes even wear on all burners. The BMC has three modes of rotation: Manual, Last-ON, or Time automatically rotating every selected time period from every hour to every 60 days.

STANDBY BOILER

• Any boiler can be conﬁgured as a Standby boiler. It withholds a speciﬁc boiler from being included in the Lead Rotation. However, the Standby boiler will be ﬁred only as a backup when all other stages combined cannot satisfy the demand and after an adjustable delay period.

SETBACK OR DAY/NIGHT SCHEDULING

Two Setback modes are available for the BMC:

• The Day/Night Scheduling provides an adjustable time-based schedule for the Setback.

• The Setback mode uses an external signal to switch the operation of the BMC in and out of setback mode.

BMC and BMC-6X Installation and Operation Manual

System Run-On

• This feature lets the BMC run the SYS relay for a longer period after the boilers have been turned off. When this relay is used to control a pump, it helps in dissipating the excess heat from the boilers combustion chamber.

INSTALLATION

Each of the BMC or BMC-6X consists of three primary enclosure components.

• The Enclosure Display Module: contains the display, buttons, LEDs and electric wiring terminals. It has two screws to hold it to the base. A program conﬁguration switch, used to adjust BMC settings, is placed above the terminals. This switch is enclosed with the enclosure wiring cover for security. Wiring terminals are of the plug-in type to ease installation and removal.

• The Enclosure Base: contains the holes to mount and hold the control against the wall or any ﬂat surface. All other enclosure components mount on the base. The bottom section of the Enclosure Base contains the wiring chamber with knockouts on the bottom to easy installation.

• The Enclosure Wiring Cover: seals the wires from the external environment. It has two screws to hold it the base and a hole to secure a lock on the wiring enclosure. A plastic web that separates the wiring chamber into high and low volt sections has been provided.

Enclosure Display Module

MOUNTING THE ENCLOSURE

• Select a location near the equipment to be controlled.

• The surface should be ﬂat and sufﬁciently wide and strong to hold the BMC or BMC-6X.

• Keep the control away from extreme heat, cold, or humidity. Ambient operating temperature is from 20 to 120°F.

• Remove the Enclosure Wiring Cover from the control enclosure by removing the two bottom screws.

• Remove the Enclosure Display Module by removing the middle screws.

• Screw the Enclosure Base to the surface through the upper and lower mounting holes on the back of the enclosure.

• Replace the Enclosure Display Module and replace the middle screws.

• Do not replace the enclosure wiring cover until all wiring is done.

• When purchasing a padlock for the enclosure, the maximum shank diameter should not exceed ¼"

Enclosure Wiring Cover Enclosure Base

Hole for optional lock

Mounting Base

Display Mounting Screws Wiring Cover Mounting Screws

BMC and BMC-6X Installation and Operation Manual

INSTALL THE SENSORS

HEATING SYSTEM SENSOR (HSS) INSTALLATION

LOCATING HSS

• Put the Heating System sensor approximately 10' feet past the last boiler on the common supply header but before any major takeoffs.

• The sensor must be located where it sees the output of all the boiler stages. If a boiler is piped so that the sensor does not see its output, the BMC will not sequence the boilers correctly.

• Only use a Standard Brass Tube sensor (389-900-230).

• The sensor wires can be extended up to 500' using a shielded 2-conductor cable (Belden #8760 or equivalent). Do not ground the shield at the sensor but at the panel using one of the terminals marked with an “O”.

• Do not run sensor wires in conduit with line voltage wiring.

IMMERSION HEATING SYSTEM SENSOR (HSS) INSTALLATION

• Install a 3/8"ID 1/2"NPT immersion well (592-300-023 or equivalent).

• Insert the sensor probe of the supplied sensor into the well.

STRAP-ON HEATING SYSTEM SENSOR (HSS) INSTALLATION

• Strap the sensor to the pipe using metal clamps. Do not over tighten the clamp.

• Strap pipe insulation around the sensor and pipe.

Immersion Heating System Sensor

Immersion Well

3/8" ID 1/2" NPT

Shield

Heating System

Sensor

Strap-On Heating System Sensor

Common Supply Pipe

Pipe Insulation

Shield

Common Supply Pipe

Sensor Probe

ALERT

If the HSS can not sense the correct heating system water temperature being supplied to the building, the BMC will not provide comfortable heat levels. Be sure the HSS is located on a main supply pipe which can not easily be isolated from the system.

OUTDOOR SENSOR INSTALLATION

• Only use the Weil McLain sensor included with the unit (389-900-229).

• Locate the sensor in the shade on the north side of the building. The sensor should never be in direct sunlight.

• Be sure the location is away from doors, windows, exhaust fans, vents, or other possible heat sources.

• The sensor should be mounted approximately 10' feet above ground level.

• Adhere the Outdoor Label provided to the back of the sensor base.

• Use the Enclosure Base bottom knockout for the conduit. Use the locknut to

hold the conduit and enclosure base together. Screw the cover to the base.

• If screws are used to afﬁx the enclosure to the wall, make sure to seal around

the sensor and wall except from the bottom.

• The sensor wires can be extended up to 500' using shielded 2-conductor cable (#18/2). Do not ground the shield at the sensor but at the control using the terminal marked with an “O”.

• Do not run sensor wires in conduit with line voltage wiring.

Seal around

sensor and wall

Mounting

Outdoor Sensor

screws

location

Outdoor

drip-hole

Outdoor

Sensor snap-in

location

Shield

not connected

Outdoor Label

on back of Sensor

Conduit

WARNING

The BMC is an operating control only. All boilers must have all safety and limit controls required by code. It is the responsibility of the installer to verify that all the safety and limits are working properly before the BMC is installed.

ALERT

Determining the proper location for the Outdoor Sensor is very important. The BMC will base the heat on the outdoor temperature information it receives from this location. If the sensor is in the sun, or covered with ice, its reading will be different from the actual Outdoor temperature (OD).

BMC and BMC-6X Installation and Operation Manual

WIRING

WIRING THE POWER (TERMINALS 1, 2)

• Bring the 120VAC 60Hz power wires through the bottom Knockout of the enclosure.

• Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring.

• Connect the hot line to terminal marked L.

• Connect the neutral line to the terminal marked N.

• Weil McLain recommends installing a surge suppressor on the power source to the BMC.

WARNING

Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring. Weil McLain recommends installing a surge suppressor on the power source to the BMC.

WARNING

Connect the shield at the control terminal end and cut the shield wire at the sensor end.

WIRING THE SENSORS

SYSTEM SENSOR WIRING (TERMINALS 27, 28)

• A BMC must be connected to a temperature sensor located in the common header.

• The BMC is designed to be connected to a 389-900-230 temperature sensor for immersion in a 3/8ID well (592-300-023 or equivalent). Contact the factory for additional temperature sensor options.

• Temperature sensor wires can be extended up to 500’ by splicing shielded 2-conductor cable (Belden #8760 or equivalent (#18/2)).

• Temperature sensors have no polarity. Connect the two wires from the sensor to the BMC terminals marked SYSTEM TEMP 27, 28.

• Connect the sensor shield to the circled terminal 28 with one of the sensor wires.

OUTDOOR SENSOR WIRING (TERMINALS 25, 26)

• When Outdoor Reset is selected, the BMC will vary the system Set Point based on outdoor temperature.

• Whether in Set Point or Outdoor Reset modes, the outdoor sensor can be used as an Outdoor Cutoff. The BMC will disable all boilers when the outdoor temperature is above the adjustable Outdoor Cutoff temperature. This feature will automatically be activated when an outdoor sensor is connected.

• For an outdoor sensor use a Weil McLain outdoor sensor (389-900-229).

• The sensor wires can be extended up to 500’ using shielded 2-conductor cable (Belden #8760 or equivalent (#18/2)).

• Temperature sensors have no polarity. Connect the wires from the outdoor sensor to the BMC terminals marked

OUTDOOR TEMP - 25, 26.

• Connect the shield to the circled terminal 26 with one of the sensor wires.

PWR

120VAC

Power Sourc

SYSTEM

OUTDOOR

TEMP

OUTDOOR

TEMP

Outdoor Sensor

Line

Neutral

PR /DH

Sensor Shiled

System Sensor

SYSTEM

TEMP

Sensor Shiled

SHUTDOWN

WIRING THE SHUTDOWN, TSTAT, OR SETBACK (TERMINALS 31, 32)

• The Shutdown will be available when selected as the Shutdown/Tstat/Setback mode from the Startup menu. See page 15. This will provide the user with a customizable Day/Night Schedule. See page 21.

PROVE

/SETBACK

/DHW

• The Shutdown feature can be used whenever it is desirable to turn off the BMC stage outputs from a remote location or another controller (i.e. EMS input).

• The Tstat option, when selected from the Shutdown/Tstat/Setback startup menu, provide the capability of controlling the operation of the BMC based on a thermostat input.

• The thermostat will provide the BMC with a call for heat by shorting terminals 31 and 32.

• When the Shutdown input is enabled by closing the dry contact, or when the Tstat input is disabled by opening the dry-contact, all active boilers will immediately modulate down to low for the Soft-Off period, then turn off.

Shutdown,

T-Stat, or

Setback Signal

• The System Output relay will remain active until the System Delay is over and then it will turn off.

• When Setback is selected in the Startup, a BMS/EMS or external clock can provide a Setback signal using these input terminals.

• The signal must be a dry contact only. No voltage can be placed across the SHUTDOWN/TSTAT/SETBACK terminals.

• Bring the two wires from the dry contact to the terminals marked SHUTDOWN/TSTAT/SETBACK- 31,32.

BMC and BMC-6X Installation and Operation Manual

WIRING THE PROVE (TERMINALS 29, 30)

• The Prove feature is provided to check system component operation and must be selected in the Startup Menu.

See page 15.

• A typical use of this feature is to check for pump ﬂow before ﬁring any boiler.

• If the PROVE input is open on a call, the BMC will enable only the System Output. All boiler outputs will be

off when the PROVE input is open.

• A factory-installed jumper provides the System Prove signal. Do not remove the jumper unless it will be

replaced by a System Prove signal or use the terminals for DHW call.

• Bring the two wires from the dry contact to the terminals marked PROVE - 29, 30. No voltage can be placed

across the PROVE terminals

WARNING

The PROVE input cannot be used as a safety limit. All equipment must have its own certiﬁed limit and safety controls as required by local codes. If Prove is selected in the startup menu, no boiler stage will start unless Prove terminals are shorted. DO NOT remove the PROVE jumper supplied unless replacing it with a Prove signal.

WIRING THE DOMESTIC HOT WATER CALL DHW (TERMINALS 29, 30)

• DHW can be used to raise system Set Point to 200°F or Maximum Water temperature, whichever is lower.

DHW with or without Priority must be selected in the Startup Menu. See page 15.

• DHW Call terminals are dry contact N.O. terminals.

• Wire an aquastat or other controls to provide closure on the DHW Call terminals.

• Remove the jumper on the DHW terminals for proper operation.

OOR

DOOR

SYSTEM

TEMP

SYSTEM

TEMP

PROVE /DHW

Prove Signal

PROVE /DHW

DHW Signal

SHUTDO

/SETBAC

SHUTDO

/SETBAC

3230

WIRING THE SYSTEM OUTPUT (TERMINALS 3, 4)

System Output Operation in Set Point Mode

• The SYS output relay will energize when the outdoor temperature drops below the Outdoor Cutoff or whenever

a boiler output is active. If no outdoor sensor is connected and the last boiler relay has de-energized, the SYS relay will remain energized for a period set by the System Run-On. See page 20.

• No boilers will be activated until the prove input is shorted. If a Prove is not required, the factory-installed

jumper should remain connected.

• A typical use of the SYS output is to activate a system pump starter. The pump can run whenever there is a call

for heat. When heat is no longer required, the pump will stay active for an adjustable Pump Run-On delay.

System Output Operation in Reset Mode

• The SYS output relay will energize whenever the outdoor temperature is below the Outdoor Cutoff.

• The SYS will remain constantly energized while the outdoor temperature is below the Outdoor Cutoff.

• When the outdoor temperature rises 2°F above the Outdoor Cutoff, the SYS output will remain energized for

the period set by the System Run-On. See page 20.

• The SYS output has one Normally Open (N.O.) relay contact rated for (1/8HP).

• The N.O. contacts are dry contacts only. They do not source any voltage.

• Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring.

• Each N.O. contact is capable of switching 6A resistive at 120VAC.

WIRING THE BOILERS

WIRING THE BOILER OUTPUTS (A TERMINALS 5, 6), (B TERMINALS 7, 8), ...

• Each boiler output (A through D) has one Normally Open (N.O.) relay contact.

• The N.O. contacts are dry contacts only. They do not source any voltage.

• Each N.O. contact is capable of switching 1Amp inductive (1/8HP), or 6A resistive at 120VAC.

• Total output of all boilers, including the SYS, must not exceed 15A.

• Wire the N.O. relay contacts in series with the unit’s limit circuit.

• Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring.

• Note that some boilers may not require the use of these outputs.

SYS

System Pump

or Pump Starter

678

Boiler

Boiler Enable

Output

+ 22 hidden pages