GSX14 Service Manual

SERVICING
139
2.5 Upon receiving a demand for auxiliary heat, the control
determines the appropriate airflow demand for heat
pump + auxiliary heat operation and operates the ECM
blower motor at that airflow demand. The control
determines which airflow demand is greatest and ap-
plies that demand when operating the ECM blower
motor.
2.6 The system operates at single stage heat pump heating
plus auxiliary heat.
2.5 Upon satisfying the thermostat, the "G" and "Y" thermo-
stat contacts (or "G", "Y" and "W1/W2" contacts) open,
removing 24VAC from the integrated air handler control.
The integrated AH control continues to operate the ECM
blower motor for an OFF delay period, then applies the
off portion of the heat pump heating ramping profile. The
ECM blower motor is then de-energized.
3.0 Continuous Fan Operation
3.1 On a demand for continuous fan operation, the thermo-
stat closes the "G" contacts providing 24VAC to the "G"
terminal at the integrated air handler control. The control
energizes the variavble speed ECM motor at 30% of the
air handler's maximum airflow capability.
3.2 Removing the thermostat demand for continuous fan
opens the "G" contacts, removing 24VAC from the
integrated air handler control. The integrated AH control
immediately de-energizes the ECM blower motor.
4.0 Defrost Operation
4.1 The control in the outdoor unit determines when a defrost
cycle is needed. Upon determing that a defrost cycle is
needed, the outdoor control de-energizes the condensor
fan motor and energizes the reversing valve. A "W1"
signal is sent from the outdoor unit control to the
integrated air handler control.
4.2 The air handler control energizes the eletric heat
sequencer output to turn on the electric heaters. The
appropriate airflow demand is provided to the motor
(greater of heat pump or auxiliary heat).
4.3 At the conclusion of the defrost cycle, the outdoor unit
control removes the "W1" output to the integrated air
handler control, de-energizes the reversing valve and
re-energizes the condensor fan motor.
5.0 Emergency Heat Operation
5.1 On a demand for emergency heat operation, the
thermostat closes the "W1/W2" contacts providing
24VAC to the "W1" terminal at the integrated air handler
control. The integrated AH control initiates the heating
ramping profile after any blower ON delays have ex-
pired. After completing any blower ON delays and
ramping profile, the control operates the variavble speed
ECM motor at the demanded airflow.
5.2 The system operates at emergency heat.
5.3 Upon satisfying the thermostat emergnecy heat de-
mand, the "W1" thermostat contacts open, removing
24VAC from the integrated air handler control. The
integrated AH control continues to operate the ECM
blower motor for an OFF delay period, then applies the off
portion of the heating ramping profile. The ECM blower
motor is then de-energized.
AVPTC/MBVC with 2-Stage Condensers (24VAC Legacy
Wired Systems)
1.0 Cooling Operation
1.1 On a demand for low stage cooling operation, the
thermostat closes the "G" and "Y1" contacts providing
24VAC to the "G" and "Y1" terminals at the integrated air
handler control. The integrated AH control initiates the
selected cooling ramping profile after any blower ON
delays have expired. After completing any blower ON
delays and ramping profile, the control operates the
variavble speed ECM motor at the demanded airflow.
1.2 The compressor and condensor fan motor are energized
by the closing of the thermostat "Y1" contacts.
1.3 The system operates at low stage cooling.
1.4 If the thermostat demand cannot be met with low stage
cooling, the thermostat closes the "Y2" contacts, provid-
ing 24VAC to the "Y2" terminal at the AH control. The
integrated AH control operates the ECM blower motor at
the high stage cooling airflow demand. Thermostat "G"
and Y1" contacts remain closed.
1.5 The compressor and condensor fan motor high stage
speeds are energized by the closing of the thermostat
"Y2" contacts.
1.6 The system operates at high stage cooling.
1.7 Upon satisfying the thermostat, the "G", "Y1" and "Y2"
thermostat contacts open, removing 24VAC from the
both the outdoor condensor and integrated air handler
control. The compressor and condensor fan motor are
both de-energized immediately. The integrated AH
control continues to operate the ECM blower motor for an
OFF delay period, then applies the off portion of the
selected ramping profile. The ECM blower motor is then
de-energized.
2.0 Heating Operation
2.1 On a demand for auxiliary heat operation, the thermostat
closes the "W1" contacts providing 24VAC to the "W1"
terminal at the integrated air handler control. The
integrated AH control initiates the heating ramping profile
after any blower ON delays have expired. After complet-
ing any blower ON delays and ramping profile, the control
operates the variavble speed ECM motor at the de-
manded airflow.
2.2 The system operates at low stage auxiliary heat.
2.3 If the thermostat demand cannot be met on low stage
auxiliary heat, the thermostat will close the "W2" con-
tacts, providing 24VAC to the "W2" terminal at theintegrated
AH control. Thermostat "W1" contacts remain closed.
2.4 The system operates on high stage auxiliary heat.