507769-05G / 31-5000656
Page 37 of 55
Issue 2223
Figure 51. Typical Field Wiring Diagram
NOTE-
IF ANY WIRE IN THIS APPLIANCE IS REPLACED,
IT MUST BE REPLACED WITH WIRE OF LIKE
SIZE, RATING, INSULATION THICKNESS AND
TERMINATION.
WARNING-
ELECTRIC SHOCK HAZARD. CAN CAUSE
INJURY OR DEATH. UNIT MUST BE GROUNDED
IN ACCORDANCE WITH NATIONAL AND LOCAL
CODES.
‘R’ IS REQUIRED ON SOME OUTDOOR UNITS
L13 POWER CHOKE USED ON 3/4 AND 1 HP
ONLY
S145 IS USED WITH GAS VALVE WHEN APPLIED
IN LP GAS UNTIS
in the heating mode when the combustion air inducer is
operating and the pressure switch is closed. Any humidifier
rated up to 0.5 amp can be connected to this terminal with
the ground leg of the circuit connected to ground or the “C”
terminal.
Figure 50. Furnace & Condensing Unit Thermostat
Designations
Thermostat
Furnace
Condensing
Unit
(Refer to specific thermostat and outdoor unit.)
COMMON
POWER
HEAT
INDOOR BLOWER
Y
C
R
G
W1
Y
C
R
G
W
COOLING
CONDENSING
CONDENSING
*CONDENSING
Install the room thermostat according to the instructions
provided with the thermostat. See Figure 50 for thermostat
designations. If the furnace is being matched with a
heat pump, refer to the FM21 installation instruction or
appropriate dual fuel thermostat instructions.
Indoor Blower Speeds
1. When the thermostat is set to “FAN ON”, the indoor
blower will run continuously on the fan speed when
there is no cooling or heating demand. See Table 22
for allowable continuous circulation speeds.
2. When the furnace is running in the heating mode, the
indoor blower will run on the heating speed.
3. When there is a cooling demand, the indoor blower will
run on the cooling speed.
Generator Use - Voltage Requirements
The following requirements must be kept in mind when
specifying a generator for use with this equipment:
• The furnace requires 120 volts ± 10% (Range: 108
volts to 132 volts).
• The furnace operates at 60 Hz ± 5% (Range: 57 Hz
to 63 Hz).
• The furnace integrated control requires both polarity
and proper ground. Both polarity and proper grounding
should be checked before attempting to operate the
furnace on either permanent or temporary power.
• Generator should have a wave form distortion of less
than 5% THD (Total Harmonic Distortion).