Electrical Wiring - Thermo Pride CMA3-50D36N Installation And Service Manual

All installations and services must be performed by qualified service personnel.
L. ELECTRICAL WIRING
All wiring shall be performed by a qualified electrician or service person. The
wiring must comply with local codes, the instructions in this manual, and in the
absence of codes with the National Electrical Code ANSI/NFPA-70 (LATEST
EDITION).
1. Electrical Branch Supply Circuit
Route all electrical wiring to the left side of the furnace. The power supply
circuit to the furnace must be installed and grounded in accordance with the
provisions of the National Electrical Code, ANSI/NFPA-70-1999, or latest
edition, and all local codes having jurisdiction.
2. Connection Of Power Supply Wires
a. Remove the cover from junction box.
b. Insert 115 VAC wires through the strain relief bushing (or conduit
connection as applicable) on the left side of the furnace junction box.
c. Connect the "hot" wire to the black wire
d. Connect the "neutral" wire to the white wire.
e. Connect the "ground" wire to the green wire.
f. Reinstall and secure the junction box cover with the original mounting
screws.
NOTICE: The hot surface igniter and operation of this furnace depends on
correct polarity. The hot leg of the supply circuit must be connected to the
black line lead (L1) and the common leg (L2) to the white line lead in the field
mounted junction box. The hot leg must pass through the disconnect switch in
all cases to prevent the hazard of electrical shock when servicing.
IMPORTANT: The furnace must be grounded in accordance with local codes
and with the National Electrical Code, ANSI/NFPA NO. 70 (Latest Edition)
when an external electrical source is utilized.
3. Connection Of Room Thermostat Wires
NOTE: Class 1 thermostat wire must be used inside the furnace burner
compartment.
a. Insert 24 VAC wires through the plastic grommet on the left side of the
furnace casing.
b. Connect the thermostat wires to the W/R 50A65-143 control (refer to the
wiring diagram).
c. Connect the thermostat wires to the room thermostat.
.
31