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
63
1.1 On a demand for cooling, the room thermostat
energizes “G” and “Y1” and 24Vac is supplied to “G” and
“Ylow/Y1” of the MBE/AEPF unit. The VSTB inside the
MBE/AEPF will turn on the blower motor and the motor
will ramp up to 60% of the speed programmed in the
motor based on the settings for dip switch 5 and 6. The
VSTB will supply 24Vac to “Ylow/Y1” at the condenser and
the compressor and condenser fan starts in low speed
operation.
1.2 If rst stage cooling cannot satisfy the demand, the
room thermostat will energize “Y2” and supply 24Vac to
the MBE/AEPF unit. The blower motor will change to the
cfm for high speed operation and the VSTB will supply
24Vac to “Y/Y2” at the condenser and the compressor and
condenser fan will change to high speed operation. When
the “Y2” demand is satised, the thermostat will remove the
“Y2” demand and the VSTB will remove the 24Vac from “Y/
Y2” at the condenser.
The blower will drop to 60% of the programmed cfm and
the compressor and condenser fan will change to low
speed.
1.3 When the rst stage cooling demand, “Y1”, is satised,
the room thermostat removes the 24Vac from “G” and “Y1”.
The MBE/AEPF removes the 24Vac from “Ylow/Y1’ at the
condenser and the compressor and condenser fan are
turned o. The blower motor will ramp down to a complete
stop based on the time and rate programmed in the motor.
2.0 Heating Operation
2.1 On a demand for heat, the room thermostat energizes
“W1” and 24Vac is supplied to terminal “E/W1” of the
VSTB inside the MBE/AEPF unit. The VSTB will turn
on the blower motor and the motor will ramp up to the
speed programmed in the motor based on the settings for
dip switch 1 and 2. The VSTB will supply 24Vac to heat
sequencer HR1 on the electric heater assembly.
2.2 HR1 contacts M1 and M2 will close within 10 to 20
seconds and turn on heater element #1. At the same time,
if the heater assembly contains a second heater element,
HR1 will contain a second set of contacts, M3 and M4,
which will close and turn on heater element #2.
If more than two heater elements are on
sequencer, HR2, which will control the 3rd and 4th
heater elements to operate on a second stage heat
demand, the PJ4 jumper on the VSTB inside the MBE/
indoors will continue to drop. The room thermostat
2.3 When the “W1” heat demand is satised, the room
thermostat will remove the 24Vac from “E/W1” and the
VSTB removes the 24Vac from HR1. The contacts on
HR1 will open between 30 to 70 seconds and turn o the
heater element(s) and the blower motor ramps down to a
complete stop.
MBE/AEPF With Two Stage ASZ & DSZ Heat Pump
Units
3.0 Cooling Operation
When used with the ASZ & DSZ two stage heat pumps,
the VSTB inside the MBE/AEPF. The “Y1” output from
the indoor thermostat must be connected to the purple
wire labeled “Ylow/Y1” inside the wire bundle marked
“Thermostat” and the purple wire labeled “Ylow/Y1” inside
the wire bundle marked “Outdoor Unit” must be connected
to “Y” at the heat pump. The “Y2” output from the indoor
thermostat must be connected to the yellow wire labeled
“Y/Y2” inside the wire bundle marked “Thermostat” and the
yellow wire labeled “Y/Y2” inside the wire bundle marked
“Outdoor Unit” must be connected to “Y/Y2” at the heat
pump.
On heat pump units, when the room thermostat is set to
the cooling mode, 24Vac is supplied to terminal “O” of the
VSTB inside the MBE unit. The VSTB will supply 24Vac to
“O” at the heat pump to energize the reversing valve. As
long as the thermostat is set for cooling, the reversing valve
will be in the energized position for cooling.