A/C Pressure Cutoff Switch

A/C PRESSURE CUT-OFF SWITCH
An A/C pressure cut-off switch is used to interrupt the operation of the A/C compressor 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 2860-3068 kPa (415-445 psi), the contacts open and interrupt the operation of the A/C compressor.
^ When the head pressure drops to 1517-1930 kPa (220-280 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 of 3103 kPa (450 psi) ensures containment of the refrigerant in the A/C system.

2. The switch contains a second set of electrical contacts for the high speed fan control which are normally open.
^ When the discharge line pressure reaches 1965-2172 kPa (285-315 psi), these contacts close and engage the high speed fan control.
^ When pressure drops to 1724 kPa (250 psi), the contacts again open and the high speed fan control is disengaged.