In cycling clutch systems with a fixed orifice tube, a low-pressure or cycling clutch switch is placed in series with the compressor clutch circuit so it can turn the clutch on or off.
Air conditioning system protection devices.
The AC cycling switch de-energizes the clutch and stops the compressor if the pressure gets below a certain level (usually about 20-25 psi) .It closes and turns on the compressor at about 40-47 psi.