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
65
4.5 As the temperature indoors increase, it will reach a
point where the “W2/W3” demand is satised. When
this happens, the room thermostat will remove the 24Vac
from “E/W1” of the MBE/AEPF. The contacts on HR1 will
open between 30 to 70 seconds and turn o the 1st and
2nd heater elements. If the “Y2” demand is present and
becomes satised the room thermostat will remove the
24Vac from “Y/Y2” of the MBE and the blower motor will
change to 60% of the programmed cfm. The VSTB will
remove the 24Vac from “Y/Y2” at the heat pump and the
outdoor fan will change to low speed operation. The heat
pump remains on along with the blower motor because the
“Y1” demand for rst stage heat will still be present.
4.6 When the rst stage heat demand “Y1” is satised, the
room thermostat will remove the 24Vac from “G” and “Ylo/
Y1” of the MBE/AEPF. The VSTB removes the 24Vac from
“Ylo/Y1” at the heat pump and the compressor and outdoor
fan are turned o. The blower motor will ramp down to a
complete stop based on the time and rate programmed in
the motor control.
5.0 Defrost Operation
On heat pump units, when the room thermostat is set to
the heating mode, the reversing valve is not energized.
As long as the thermostat is set for heating, the reversing
valve will be in the de-energized position for heating except
during a defrost cycle.
5.1 The heat pump will be on and operating in the heating
mode as described the Heating Operation in section 4.
5.2 The defrost control in the heat pump unit checks to see
if a defrost is needed every 30, 60 or 90 minutes of heat
pump operation depending on the selectable setting by
monitoring the state of the defrost thermostat attached to
the outdoor coil.
5.3 If the temperature of the outdoor coil is low enough to
cause the defrost thermostat to be closed when the defrost
board checks it, the board will initiate a defrost cycle.
5.4 When a defrost cycle is initiated, the contacts of
theHVDR relay on the defrost board open and turns o the
outdoor fan. The contacts of the LVDR relay on the defrost
board closes and supplies 24Vac to “O” and “W2”. The
reversing valve is energized and the contacts on HR1 close
and turns on the electric heater(s). The unit will continue to
run in this mode until the defrost cycle is completed.
5.4a For models with defrost control PCBDM133 or
PCBDM160, a 30 second compressor delay at defrost
initiation/termination is optional. As shipped from the
factory, the control is set for the delay (“DLY”), which will
turn the compressor o for 30 seconds while the reversing
valve shifts to/from the cooling mode position. To bypass
the delay, which typically reduces sound levels during
defrost mode, change the pin settings from “DLY” to
“NORM”.
5.5 When the temperature of the outdoor coil rises
high enough to causes the defrost thermostat to
open, the defrost cycle will be terminated. If at the
end of the programmed 10 minute override time the
defrost thermostat is still closed, the defrost board will
automatically terminate the defrost cycle.