Refrigerant Pressure Sensor / Switch: Description and Operation

A/C Pressure Switch





When the system pressure is 12 bar, medium A/C demand, the operation of this switch (2) causes a 6 volt series feed to both engine cooling fans, thus providing half fan speed.



Trinary Switch





This three function pressure switch (1), cuts electrical power to the compressor clutch if the system pressure is not in a range of 2 bar (1st function) to 27 bar (2nd function). The switch also provides a 12 volt supply to both engine cooling fans when maximum A/C cooling is required and operates at 20 bar input (3rd function).