Pressure Cycling Switch
NOTE:
Pressure cycling switch may also be referred as low pressure cut-off switch.
Switch is mounted on a Schrader valve type fitting and controls compressor operation. If low-side pressure decreases to approximately 23 psi (1.6 kg/cm2 ), switch opens, interrupting power to A/C compressor clutch. When pressure increases to about 46 psi (3.2 kg/cm2 ), switch closes, providing power to clutch. Switch maintains evaporator surface at a temperature slightly warmer than freezing, to prevent evaporator icing and airflow blockage during normal system operation.