Refrigerant Pressure Sensor / Switch: Description and Operation

PRESSURE SWITCH




The pressure switch is a high-pressure side component of the refrigeration cycle (cooling cycle). It consists of a diaphragm that receives refrigerant gas pressure, a snap plate, a rod, and contacts that open both when the gas pressure is too low and when it is too high.

The pressure switch plays the following roles:
- Preventing "no-gas" operation due to leakage (when gas pressure is too low)
- Protecting the cooling system against abnormally high refrigerant pressure (when gas pressure is too high)
- Detection of compressor load (mid pressure contact: electric cooling fan output control)




ON-OFF PRESSURES