Function and principle of pressure switch sensor in automobile air conditioning

The electromagnetic clutch of Automobile air-conditioning compressor controls the three-stage pressure switch, the external temperature switch and the water temperature switch through the controller. the air-conditioning compressor relay will cut off electromagnetic clutch If the refrigeration system failure and can not meet conditions defined by the above switches,. the refrigeration system will not continue to work until meet all the conditions

The function of pressure switch of Automobile Air Conditioner:The mechanical pressure switch is installed in the refrigerant circulation pipeline of the automobile air conditioner to detect the pressure of the refrigeration circulation system.it  will start the corresponding protection circuit to prevent damage to the system when the pressure is abnormal.

Pressure switch is  to prevent excessive pressure from damaging the machine. Temperature control switch is the role of keeping constant temperature and automatically stop refrigeration when reaching the set temperature .

The pressure switch of Automobile air-conditioning is installed in the refrigerant circulation pipeline . The common pressure switch are high-pressure switch, low-pressure switch, double pressure switch and triple pressure switch.

1：Low pressure switch sensor

Location of low-pressure switch is on high-pressure line of refrigeration system.The leakage of the refrigeration system will cause the lack of refrigerants , will increase the compressor vacuum degree ,and  finally causes the compressor to burn down because does not have the refrigerator.so when the pressure of high-pressure pipeline is below 0.2 MPA, the low-pressure switch cuts off the electromagnetic clutch to protect the compressor.

2：High pressure switch sensor

The high-voltage switch is installed on the condenser inlet line,High-voltage switch is used to adjust the speed of the fan motor, so that the condenser pressure is limited in a certain range.If the condensing pressure is below 1.51 MPA, the fan will rotate at a low speed; if the condensing pressure is above 1.5 MPA, the fan will rotate at a high speed.

3：Double temperature switch sensor

The double temperature switch is located next to the condenser.Condensing Fan Motor is controlled by high voltage switch and engine coolant dual temperature switch.When the coolant temperature is below 93 °C and the air-conditioning compressor is not started, the cooling fan does not turn., the cooling fan rotates at low speed when the coolant temperature is between 95 °C and 102 °C.When the coolant temperature is higher than 102 °C, the cooling fan rotates at high speed.

4：triple pressure switch sensor

The triple pressure switch in the  refrigeration system is installed on the pipeline connected the compressor and the condenser.The triple pressure switch has three pressure values. the electromagnetic clutch of the compressor disconnects when the pressure is lower than 0.22 MPA or higher than 3.2 MPA,When the pressure is less than 3.2 MPA and more than 0.22 MPA, the compressor electromagnetic clutch Suction closure.When the pressure is higher than 1.6 MPA, the cooling fan turns at high speed.

5：External temperature switch sensor

The External temperature switch is installed near the wiper motor.When the external temperature is below 5 °c, the external temperature switch disconnects the compressor electromagnetic clutch, and the air-conditioning compressor does not work at that time.