Service manual

SERVICING
140
2.5 Upon receiving the high stage auxiliary heat demand, the
control operates the ECM blower motor at the high stage
auxiliary heat airflow.
2.6 Upon satisfying the thermostat, the "W1" thermostat
contacts (or "W1" and "W2" contacts) open, removing
24VAC from the integrated air handler control and
outdoor unit. The compressor and condensor fan motor
are immediately de-enerized. 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.
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.
AVPTC/MBVC with 2-Stage Heat Pumps (24VAC Legacy
Wired Systems)
1.0 Cooling Operation
1.1 On a demand for low stage cooling operation, the
thermostat closes the "G", "O", and "Y1" contacts
providing 24VAC to the "G", "O", 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 complet-
ing any blower ON delays and ramping profile, the
control operates the variavble speed ECM motor at the
low stage cooling airflow.
1.2 The low stage compressor and condensor fan motor
speeds are energized by the closing of the thermostat
"Y1" contacts. The reversing valve is energized with the
closing of the thermostat "O" 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",
"O", 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", "O", and "Y1"
(or "Y1" and "Y2") thermostat contacts open, removing
24VAC from the both the outdoor condensor and
integrated air handler control. The compressor,
condensor fan motor, and reverving valve are all 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 low stage heat pump heating, the room
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
heat pump heating 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 low stage heat pump
airflow.
2.2 The low stage compressor and condensor fan motor
speeds are energized by the closing of the thermostat
"Y1" contacts.
2.3 The system operates at low stage heat pump heating.
2.4 If the thermostat demand cannot be met with low stage
heat pump heating, the thermostat will close the "Y2"
contacts, providing 24VAC to the "Y2" terminals at the
integrated AH control and heat pump. Thermostat "G"
and "Y1" contacts remain closed. The air handler control
operates the ECM blower motor at the high stage heat
pump heating airflow.
2.5 The system operates at high stage heat pump heating.
2.6 If the thermostat demand cannot be met with high stage
heat pump heating, the thermostat will close the "W1/W2"
contacts, providing 24VAC to the "W1" or "W1" and "W2"
terminals at the integrated AH control. Thermostat "G",
"Y1", and "Y2" contacts remain closed.
2.7 Upon receiving a demand for auxiliary heat, the control
determines the appropriate airflow demand for high
stage heat pump + auxiliary heat operation and operates
the ECM blower motor at that airflow demand. The control
determines which airflow demand is greatest and applies
that demand when operating the ECM blower motor.
2.8 The system operates at high stage heat pump heating
plus auxiliary heat.
2.9 Upon satisfying the thermostat, the "G" and "Y1" thermo-
stat contacts (or "G", "Y1", "Y2" and "W1/W2" contacts)
open, removing 24VAC from the integrated air handler
control. The compressor and condensor fan motor are
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 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.