ASPT Service Manual
Table Of Contents
- IMPORTANT INFORMATION
- PRODUCT IDENTIFICATION
- Checking Voltage
- Checking Wiring
- Checking Thermostat And Wiring
- Thermostat Wiring
- Checking Transformer And Control Circuit
- Checking Contactor And/Or Relays
- Checking Contactor Contacts
- Checking Fan Relay Contacts
- Checking Loss Of Charge Protector (Heat Pump Models)
- Checking High Pressure Control
- Checking Low Pressure Control
- Copeland Comfort Alert™ Diagnostics - 3-Wire module
- Copeland Coresense™ Diagnostics - 3-Wire module
- Checking Capacitor
- Resistance Check Using A Digital Multi-Meter
- Capacitance Check Using A Digital Multi-Meter (In Capacitance Mode)
- Testing a Run Capacitor Under Load
- Checking Outdoor Fan and Blower Motors (PSC Motors)
- Checking Fan and Blower Motor (ECM Motors)
- Checking ECM Motor Windings
- ECM CFM Adjustments MBE/AEPF
- Blower Performance Data
- Checking High Efficiency Motors
- EEM Blower Replacement
- MBR/AR*F Electronic Blower Time Delay Relay
- Checking Compressor
- Resistance Test
- Ground Test
- Unloader Test Procedure
- Operation Test
- Checking 3-Phase Scroll Compressor Rotation
- Testing Crankcase Heater (Optional Item)
- Checking Reversing Valve and Solenoid
- Testing Defrost Control
- Testing Defrost Thermostat
- Checking Heater Limit Control(s)
- Checking Heater Elements
- Electric Heater (Optional Item)
- Checking Heater Limit Control(s)
- Checking Heater Elements
- Refrigeration Repair Practice
- Leak Testing (Nitrogen or Nitrogen-Traced)
- Evacuation
- Charging
- Checking Compressor Efficiency
- Overfeeding
- Underfeeding
- Checking Superheat
- Subcooling on Expansion Valve System
- Checking Expansion Valve Operation
- Checking Restricted Liquid Line
- Overcharge Of Refrigerant
- Non-Condensables
- Compressor Burnout
- Refrigerant Piping
- Duct Static Pressures
- Single Piece Air Handler External Static
- Two Piece Air Handler External Static Pressure
- Furnace External Static Pressure
- Periodic Maintenance
SYSTEM OPERATION
57
Heating Cycle
The reversing valve on the GSZ, SSZ, ANZ, ASZ and DSZ
models is energized in the cooling cycle through the “O”
terminal on the room thermostat.
These models have a 24 volt reversing valve coil. When
the thermostat selector switch is set in the cooling position,
the “O” terminal on the thermostat is energized all the time.
Care must be taken when selecting a room thermostat.
Refer to the installation instructions shipped with the
product for approved thermostats.
When the room thermostat calls for heat, the contacts of
the room thermostat close making terminals R to Y & G,
the low voltage circuit of the transformer is completed.
Current now ows through the magnetic holding coils of the
compressor contactor (CC) and fan relay (RFC).
This draws in the normally open contact CC, starting the
compressor condenser fan motors. At the same time,
contacts RFC close, starting the indoor fan motor.
When the thermostat is satised, it opens its contacts,
breaking the low voltage circuit, causing the compressor
contactor and indoor fan relay to open, shutting down the
system.
If the room thermostat fan selector switch should be set
to the “on” position, then the indoor blower would run
continuously rather than cycling with the compressor.
When the thermostat is satised, appropriate commands
are sent to the UC control. The compressor relay and
outdoor fan relay is de-energized. The compressor high
stage solenoid is de-energized if it was energized. The UC
control sends an appropriate command to the indoor unit to
de-energize the indoor blower motor.
Indoor
Coil
Accumulator
Bi-Flow
Filter Dryer
Outdoor
Coil
Thermostatic
Expansion
Valve
Check Valve
Reversing Valve
(De-Energized)
Indoor
Coil
Accumulator
Bi-Flow
Filter Dryer
Outdoor
Coil
Thermostatic
Expansion
Valve
Check Valve
Reversing Valve
(Energized)
Heating Cycle