Low Pressure Sensor / Switch: Description and Operation

LOW-CHARGE PROTECTION SWITCH

The low-charge protection switch is used to prevent A/C compressor damage in the event of a low refrigerant charge.
- The electrical switch contacts open when the suction pressure drops below normal levels. The contacts close when the suction pressure rises. For specifications regarding operating pressure(s), refer to Specifications.
- When the low-charge protection switch contacts open, the A/C clutch field coil is de-energized and compressor operation stops.
- The low-charge protection switch is mounted on a Schrader valve-type fitting on the top of the suction accumulator/drier.
- A valve depressor, located inside the threaded end of the low-charge protection switch, presses in on the Schrader valve stem, allowing the suction pressure inside the suction accumulator/drier to control the operation of the low-charge protection switch.
- It is not necessary to discharge the refrigerant system to remove the low-charge protection switch.