A/C Pressure Cutoff Switch

An A/C pressure cut-off switch is used to interrupt the A/C compressor operation in the event of high system discharge pressures.

DUAL
The A/C pressure cut-off switch has two sets of contacts.
1. One electrical contact is normally closed.
^ When the compressor head pressure rises to approximately 2896 kPa (420 psi), the contacts open and the compressor operation is shut off.
^ When the head pressure drops to approximately 1724 kPa (250 psi), the contacts again close and allow operation of the A/C compressor.

NOTE: Shutting down the compressor operation prior to the pressure relief valve set point 3103 kPa (450 psi) ensures containment of the refrigerant in the A/C system.

2. A second set of electrical contacts for the fan motor which are normally open.
^ When the discharge line pressure reaches approximately 2241 kPa (325 psi), these contacts close and engage the fan motor.
^ When the pressure drops to approximately 1896 kPa (275 psi), the contacts again open and the fan motor is disengaged.