OUTDOOR UNIT CONTROLS & COMPONENTS
PAGE 12
ENGLISH
4-Way Valve
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 orice. 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 orice 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 orice size to maintain a 
superheat level of around 10°F. 
The 4-Way Valve redirects the ow 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 ow 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 ow. 
The 4-Way Valve is electrically connected to the Main Control 
Board at PLUG CN-10. 
Accumulator
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 
operation. 
Refrigerant Filters
Electrical Base Pan Heater
The system has debris catching lters that protect internal 
system components from contaminants in the refrigerant. 
The lter is a permanent part that is not typically replaced. 
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 system has an electrical base pan heater for defrosting.