In a pump down system, where is the solenoid typically located?

In a pump down system, the solenoid valve is typically located before the metering device. This configuration allows the solenoid to control the flow of refrigerant entering the metering device based on the system's operational needs. When the solenoid is energized, it opens, allowing refrigerant to flow through to the evaporator via the metering device. This position is crucial for ensuring that the refrigerant is properly managed during the pump down process, where refrigerant is returned to the compressor to minimize the charge in the evaporator and lines for maintenance or service.

If the solenoid were located after the metering device, it would hinder the ability to effectively manage the refrigerant flow to the evaporator when the system is operating under different pressures and temperatures. Therefore, positioning the solenoid before the metering device optimally facilitates the control necessary in a pump down cycle.