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.

Immersion Heating System Sensor

Immersion Well

 

Common Supply Pipe

3/8" ID 1/2" NPT

 

 

 

 

 

 

 

 

Shield

Heating System

• 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

Sensor

Sensor Probe

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.

Strap-On Heating System Sensor

Common Supply Pipe

Pipe Insulation

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.

Shield

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

Outdoor 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.

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.

Seal around sensor and wall

Mounting

screws location

Outdoor drip-hole

Outdoor

Sensor snap-in location

Shield

not connected

Outdoor Label on back of Sensor

Conduit

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).

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Weil-McLain BMC-6X Install the Sensors, Heating System Sensor HSS Installation, Outdoor Sensor Installation