Electrical Wiring - Carrier BW4 Installation, Start-Up, And Operating Instructions Manual

Oil-fired cast iron hot water boilers sizes 74,000 through 239,000 series a

Table of Contents

See Fig. 13-15 for wiring diagrams for the various models.

PROCEDURE 1—INSTALLING THERMOSTAT (NOT PROVIDED)

The 24-v thermostat location has an important effect on operation of boiler system. BE SURE TO FOLLOW INSTRUCTIONS INCLUDED

WITH THERMOSTAT.

PROCEDURE 2—GROUNDING

Permanently ground boiler according to local codes and the National Electrical Code. Run a 14 gage or heavier copper wire from boiler to a

grounded connection in service panel or a properly driven and electrically grounded ground rod.

PROCEDURE 3—ELECTRIC POWER SUPPLY

WARNING: Turn off electric power at fuse box before making any line voltage connections. Follow local electric

codes. Failure to follow this warning could result in electrical shock, personal injury, or death.

All electrical work must conform to local codes as well as the National Electrical Code. If not familiar with wiring and codes in general, have a

competent electrician do this job.

Boiler controls are all wired at the factory. All that is required is to connect a 115-v electric supply and thermostat wires to aquastat relay.

Run a separate circuit from a separate overcurrent protective device in electrical service entrance panel. This should be a 15-amp circuit. Locate

a shutoff switch at boiler. It must be turned OFF during any maintenance. Solder and tape or securely fasten these connections with wire nuts.

PROCEDURE 4—CONNECTING 115-V ELECTRIC WIRING TO BOILER

Connect 115-v electric supply wires to terminals L1 and L2 on aquastat relay. (See Fig. 12.)

PROCEDURE 5—THERMOSTAT CONNECTIONS

A. Boilers Without Tankless Coil

The 2 wires from thermostat connect to terminals T and T on L8148A aquastat relay.

B. Boilers With Tankless Coil

The 2 wires from thermostat connect to terminals T and T on L8124C aquastat relay.

PROCEDURE 6—THERMOSTAT HEAT ANTICIPATOR ADJUSTMENT

Set heat anticipator at 0.2 amps.