Refrigerant Pressure Sensor / Switch: Description and Operation

OPERATION

The triple pressure switch is a combination of the low pressure switch (for checking the quantity of refrigerant) and the high pressure switch (for prevention of air conditioning line burst) and medium pressure switch (for cooling fan operation). It is installed in the receiver drier and when the pressure becomes approximately 200 kPa (29 psi) or lower, the compressor stops, thus preventing the compressor from being damaged by sticking. When the pressure reaches 1,800 kPa (281 psi) or higher, the cooling fans run high speed from low speed, thus preventing the power consumption of cooling fans from being discharged. When the pressure reaches 3,241 kPa (470 psi) or higher, the compressor stops, thus preventing air conditioning line burst. There is generally no necessity for inspection; if, however, an unusual condition, such as nonoperation of the compressor is encountered, check by following the procedures.