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All installations and services must be performed by qualified service personnel.
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f. Reinstall and secure the junction box cover with the original mounting screws.
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.
IMPORTANT: The room thermostat should be installed 4 to 5 feet above the floor
on an interior wall which is relatively free from direct sources of heat (sunlight or
supply airflow) or exposure to cold (drafts from open windows and doors). The
nominal anticipator setting is 0.8 amperes, for the GMD (refer to the thermostat
literature for additional information).
Five-conductor thermostat wire is recommended for 24 VAC, low-voltage, control
circuit wiring. How ever only 2 wires are required for the furnace (a heating
application only).
Electrical Wire Diameter
Maximum Recommended
Thermostat Wire Length
(AWG)
(Feet)
24 55
22 90
20 140
18 225
Once the furnace is installed, check the thermostat anticipator for proper nominal
setting.
1. Connect a multimeter, capable of reading milliamps (mA), in series
with the low voltage wires to the thermostat.
1. Increase the thermostat setting, or create a “call for heat”.
2. Read the value of the thermostat current, in milliamps.
3. Adjust the heat anticipator of the thermostat to the value read by the
multimeter.
If the heat anticipator is set too high, the furnace may delay activation of a heating
cycle for too long. If the heat anticipator is set too low, the furnace may cycle too
frequently. Either condition may not provide optimal comfort to the homeowner.