Haier AW09TE1VHA, Service Manual

Page: 12 / 79

OUTDOOR UNIT CONTROL S and COMPONENTS PAGE 12
ENGLISH
4-Way Valve
Electronic Expansion Valve
Accumulator
Refrigerant Filters
The 4-Way Valve redirects the flow of refrigerant in the piping
circuit to allow the system to reverse the functions of the indoor
and outdoor coils. When de-energized in COOL MODE, the
valve will direct the refrigerant hot gas to the outdoor coil.
When energized in HEAT MODE, the valve will direct the hot
gas to the indoor coil.
The direction of flow is changed by an electrical solenoid that
moves an internal slide mechanism when energized.
The 4-Way Valve is electrically connected to the Main Control
Board at PLUG CN-10.
The metering device is an electronic expansion valve .
The valve consists of an electrical operator and a valve
body with internal variable size orifice. When operating,
the Main Control Board will send pulses of voltage to the
electrical operator. The operator will then magnetically move
the position of the metering orifice pin to vary the flow of
refrigerant through the valve.
The metering device position is determined by input from
a Suction Line Temperature Sensor located in the outdoor
unit. The EEV will change the internal orifice size to maintain a
superheat level of around 10°F.
During COOL MODE operation, the valve meters low
pressure refrigerant to the indoor coil. During HEAT MODE
operation, the valve meters low pressure refrigerant to the
outdoor coil.
The Accumulator is located in the suction line circuit at the
entrance to the compressor. The accumulator helps prevent
liquid refrigerant from entering the compressor .
The system has debris-catching filters that protect internal
system components from contaminants in the refrigerant.
The filter is a permanent part that is not typically replaced.