Heating Mode Sequence Of Operation - GE ASH220NCDWA Service Manual

Heating Mode Sequence of Operation

On a call for heating, the indoor unit will send the room temperature and set-point requirement to the outdoor unit PCB via the
data signal wire path. The data travels from the indoor unit to the outdoor unit via the wire located on terminal 3/C. The indoor
unit louvers will open. The fan will not start until the coil has warmed sufficiently to avoid cold drafts.
EEVs serving indoor circuits will step to the standard opening. The outdoor EEV opens to a position based upon the outdoor air
temperature.
The 4-way valve will energize and the outdoor fan will start. The compressor starts at a slow speed and will increase based upon
demand. The indoor fan starts after the indoor coil is warm enough to avoid circulating cool air.
With the compressor operating, refrigerant will begin to flow throughout the refrigeration circuit.
The operating frequency of the compressor will be displayed on the Service Monitor Board.
When the compressor starts, hot gas will flow into the oil separator. Oil will be trapped in the separator and returned to the
suction inlet of the compressor via the capillary tube assembly low pressure path.
4-way valve coil:
Refrigerant flow in cooling
OFF
ON
Refrigerant flow in heating
2
Indoor
heat
exchanger
temp.
sensor
FAN-IN
Indoor
ambient
temperature
sensor
Indoor unit A
Indoor unit B
Indoor unit C
B-8
2
Unit A gas pipe temp. sensor Tc1
Indoor unit A
Unit B gas pipe temp. sensor Tc1
Indoor unit B
Unit C gas pipe temp. sensor Tc1
Indoor unit C
3
Unit A liquid pipe temp. sensor Tc2 Strainer
Unit B liquid pipe temp. sensorTc2 Strainer
Unit C liquid pipe temp. sensor Tc2 Strainer
OUTDOOR TECHNICAL OVERVIEW
Operations
Comp-
ressor
1
Oil
separator
High pressure
switch
Gas service valve
5/8
EEV A
EEV B
Liquid service valve
EEV C
3/8
Receiver
6
Low pressure
Suction temp.
switch
sensor Ts
Discharge temp.
sensor
Accumulator
Capillary tube
Ø2.7*Ø1.0*1400
Pipe sensor
4-way valve
Toci
Outdoor
heat
exchanger
temp.
sensor
EEV O
Strainer
5
FAN-OUT
Outdoor
ambient
temperature
sensor Ta
Defrost
sensor Td Te
4
Distributor