Compressor Cut-Off/Cycling Switch

PRESSURE CYCLING SWITCH

The refrigeration cycle (on and off operation of the compressor) is controlled by a switch which senses

the low-side pressure as an indicator of evaporator temperature. The pressure cycling switch is the freeze protection device in the system and senses refrigerant pressure on the suction side of the system. This switch is mounted on a standard Schrader-type valve low-side fitting. This switch also provides compressor cut-off during cold weather.

Additional compressor protection results from the operating characteristics of the low-side pressure cycling system. If a massive discharge occurs or the orifice tube becomes plugged, low-side pressures could be insufficient to close the contacts of the pressure switch. In the event of a low charge, insufficient cooling accompanied by rapid compressor clutch cycling will be noticed at high outside (ambient) air temperatures.

NOTE: If replacement of the pressure cycling switch is necessary, this may be done without removing the refrigerant charge. A Schrader-type valve is located in the pressure switch fitting. During replacement of the pressure switch, a new O-ring seal must be installed and the switch assembled to the specified torque of 6.5 Nm (58 lbs. in.).