ESCO Air Conditioning Practice Exam

What is true about a solenoid valve in a pump down system?

1. It is located on the suction line before the evaporator

2. It is located on the discharge line after the compressor

3. It is located before the metering device

4. It controls the oil pressure safety switch

The correct answer is: It is located on the suction line before the evaporator

In a pump down system, a solenoid valve is typically located on the suction line before the evaporator. This placement allows the solenoid valve to effectively stop the flow of refrigerant into the evaporator and isolate the refrigerant in the system for pump down operations. By closing the solenoid valve on the suction line, the compressor is able to pump down the refrigerant into the condenser, resulting in pressure equalization in the system. This prevents the compressor from restarting under high head pressure conditions and helps protect the system components from potential damage.