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WARNING
The system must not be in either the passive or ac
tive dehumidification mode when charging a cooling
system.
Single Stage Cooling
A call for cooling from the thermostat closes the R to Y cir
cuit on the integrated ignition/blower control board. The
control waits for a 1-second delay before energizing the cir
culating blower to 82% of the selected cooling CFM (pas
sive dehumidification mode). After 7.5 minutes, the circu
lating blower automatically ramps up to 100% of the
selected cooling airflow. When the call for cooling is satis
fied, the circulating blower ramps back down to 82% of the
selected cooling airflow for 1 minute, then shuts off.
Two-Stage Cooling
A call for 1st stage cooling from the thermostat closes the R
to Y circuit on the control board. The control waits for a 1-
second delay before energizing the circulating blower. The
blower motor runs at 57% of the selected air flow for the first
7.5 minutes of the 1st stage cooling demand (passive de
humidification mode). After 7.5 minutes, the blower motor
runs at 70% of the selected cooling air flow until 1st stage
cooling demand is satisfied.
A call for 2nd stage cooling from the thermostat closes the
R to Y2 circuit on the control board. The blower motor
ramps up to 100% of the selected cooling air flow. When
the demand for cooling is met, the blower ramps down to
Y1 until satisfied, then ramps down to 57% for 1 minute,
then turns off.
Heat Pump
For heat pump operation, clip the jumper wire located bel
low the O terminal on the integrated ignition/blower control
board. In heat pump mode, a call for heat will result in the
circulating air blower operating at the selected cooling air
flow after a brief ramp-up period.
Emergency Replacement Motor Operation
If the variable speed motor needs to be replaced in an em
ergency situation (such as “no heat”) and an exact replace
ment motor is not immediately available, a standard PSC
motor of equivalent frame size, voltage, rotation, and
horsepower can be temporarily installed until the correct
replacement motor can be obtained.
Connect the desired speed tap to the “EAC” terminal and
the neutral tap to the neutral terminal on the ignition control
(refer to the furnace wiring diagram). The ignition control
will control the motor’s operation, including a nominal 20
second “on” delay with a call for heat and a nominal 180
second “off” delay when the thermostat is satisfied. It will
also operate the motor on a call for cooling, with no “on” or
“off” delays.
Verify that the unit is operating at the desired speed and
within the rise range as shown on the unit rating plate.
The correct replacement motor must be installed as
soon as possible to ensure continued satisfactory op
eration of the furnace.
Service
WARNING
ELECTRICAL SHOCK, FIRE,
OR EXPLOSION HAZARD.
Failure to follow safety warnings exactly could result
in dangerous operation, serious injury, death or
property damage.
Improper servicing could result in dangerous opera
tion, serious injury, death, or property damage.
Before servicing, disconnect all electrical power to
furnace.
When servicing controls, label all wires prior to dis
connecting. Take care to reconnect wires correctly.
Verify proper operation after servicing.
At the beginning of each heating season, system should be
checked as follows by a qualified service technician:
Blower
Check the blower wheel for debris and clean if necessary.
The blower motors are prelubricated for extended bearing
life. No further lubrication is needed.
WARNING
The blower access panel must be securely in place
when the blower and burners are operating. Gas
fumes, which could contain carbon monoxide, can
be drawn into living space resulting in personal inju
ry or death.
Filters
All air filters are installed external to the unit. Filters should
be inspected monthly. Clean or replace the filters when
necessary to ensure proper furnace operation. Table 3 lists
recommended filter sizes.
Exhaust and air intake pipes
Check the exhaust and air intake pipes and all connections
for tightness and to make sure there is no blockage.
NOTE
- After any heavy snow, ice or frozen fog event the
furnace vent pipes may become restricted. Always check
the vent system and remove any snow or ice that may be
obstructing the plastic intake or exhaust pipes.
Electrical
1 - Check all wiring for loose connections.
2 - Check for the correct voltage at the furnace (furnace
operating).
3 - Check amp-draw on the blower motor.
Motor Nameplate__________Actual__________
