In this month’s troubleshooting situation, the equipment that needs servicing is a split system and the refrigerant flow control is handled via an EEV (Electronic Expansion Valve, shown in Figure One, top).
In addition to the valve itself, an EVC (Electronic Valve Control board) and two sensors are employed to control refrigerant flow. One sensor is known as an ET, which is designed to monitor evaporator temperature, and the other is a GT, which is designed to monitor refrigerant vapor temperature, and it is positioned on the suction line side of the evaporator coil. Figure Two shows you the design of the system sensors.