The 4-Way Valve redirects the flow of refrigerant in the piping
circuit to allow the system to swap 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 valve flow direction capability is controlled by an
electrical solenoid. When energized by 240 Volts, line voltage,
the solenoid will magnetically move an internal slide within
the 4-Way Valve to change the direction of refrigerant flow.
The 4-Way Valve is electrically connected to the Main Control
Board at PLUG CN-10.
Electronic Expansion Valve
The metering device is an electronic expansion valve type
EEV. 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 its size.
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.
OUTDOOR UNIT CONTROLS & COMPONENTS
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
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 during run
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.