A/C Pressure Switch

A/C Cycling Switch:

The A/C cycling 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 A/C cycling switch, presses in on the Schrader valve stem.
- This allows the suction pressure inside the suction accumulator/drier to control the operation of the A/C cycling switch.
- The electrical switch contacts open when the suction pressure drops to 152-193 kPa (22-28 psi).
- The contacts close when the suction pressure rises to 276-324 kPa (40-47 psi).
- When the A/C cycling switch contacts close, the A/C clutch field coil is energized.
- When the A/C cycling switch contacts open, the A/C clutch field coil is deenergized and compressor operation stops.
- The A/C cycling switch will control the A/C evaporator core pressure at a point where the plate/fin surface temperature will be maintained slightly above freezing.
- This prevents icing of the A/C evaporator core and blockage of airflow.
- It is not necessary to discharge the refrigerant system to remove the A/C cycling switch.