Page 10 of 14 506271-01Issue 0921
7. After reassembly of all parts is complete and all wires
are reconnected, open the main manual gas shutoff valve;
check for and correct any gas leaks. Turn electrical power
on, initiate a call for heat, and check for proper burner
operation.
8. Install burner access panel.
Heat Anticipator
The heat anticipator setting is 0.75 amp. It is important
that the anticipator setpoint be correct. Too high of a setting
will result in longer heat cycles and a greater temperature
swing in the conditioned space. Reducing the value below
the correct setpoint will give shorter “ON” cycles and may
result in the lowering of the temperature within the
conditioned space.
OPERATION
Cooling System
The cooling system is a complete factory package utilizing an
air-cooled condenser and is factory-charged with HFC-R-410A.
The compressor is hermetically sealed and base mounted
with rubber-insulated hold-down bolts.
Unit compressors have internal protection. In the event there
is an abnormal rise in the temperature of the compressor, the
protector will open and cause the compressor to stop.
Preliminary Operation Cooling
After the initial installation, the compressor should be given
three false starts (energized just long enough to make a few
revolutions), with 5 – 7 minutes between each start, before
being put into full-time service.
Cooling Sequence of Operation
When the thermostat calls for cooling, R is closed to G and
Y (see the wiring diagram found on page 13). This action
completes the low voltage control circuit, energizing the
compressor, condenser fan motor, and blower motor.
Blower Delay – Cooling
The circulating air blower is controlled by a timing circuit in
the integrated blower/ignition control. Timings are not
adjustable. Blower “ON” delay is 5 seconds after the
compressor starts and blower “OFF” timing is 90 seconds
after the cooling system shuts down.
System Performance
For maximum performance of the cooling system, operating
temperatures and pressure should be checked. Superheat
should be determined at Standard ARI test conditions of 82°F
outdoor and 80°F indoor dry bulb/67°F wet bulb. If superheat
measured deviates from values found in Table 3, refrigerant
charge should be adjusted accordingly for maximum
performance.
does not sense that a flame has been established in the
Heating System
With the proper thermostat and sub-base, continuous blower
operation is possible by closing the R to G circuit. Cooling
blower delay is also functional in this mode.
Heating Sequence of Operation
The following sequence describes the operation of the gas
heat section.
1. When the thermostat calls for heat, the draft motor is
energized by the 24-volt relay in the blower ignition control
which closes the 240V contact to the draft motor.
2. When the speed of the draft motor reaches proper RPM,
the pressure switch closes to power the ignition control.
3. When PSW on ignition control is energized, a pre-purge
time is initiated (30 seconds nominal).
4. When pre-purge has expired, the gas valve is energized
for direct ignition. The ignition control energizes the main
gas valve and spark electrode for a period of 10 seconds.
5. Thirty seconds nominal after the initial trial for ignition,
the circulation air blower will start. If the flame sensor
Suction Superheat
Table 3
* This letter will vary according to furnace series.