Refrigerant Pressure Sensor / Switch: Description and Operation
LOW CHARGE PROTECTION SWITCHCAUTION: It is necessary to recover the refrigerant from the A/C system before removing the 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, by interrupting the ground signal circuit between the refrigerant containment switch and ground, when the low side refrigerant pressure drops below acceptable levels. The electrical switch contacts open when the suction pressure drops below normal levels. The Contacts close when the suction pressure rises.
The low charge protection switch is mounted on the TXV.