Air Conditioning Three State Pressure Switch
This is an air conditioner three-state pressure switch, which includes a high and low pressure switch and a medium voltage switch. The three-state pressure switch is installed on the high-pressure pipeline of the air-conditioning system.
Low-pressure switch: When the air-conditioning system leaks or the refrigerant is low, in order to protect the compressor from damage, the control circuit of the compressor is forcibly cut off to stop the compressor.
Mid-state switch: When the condensing pressure is high, force the condensing fan to rotate at a high speed to reduce the high pressure pressure and increase the cooling effect.
High pressure switch: In order to prevent the system pressure from being too high, causing the system to explode, the compressor is forced to stop working. When the high-pressure pressure of the air conditioner is abnormally high, the high-pressure switch is opened to cut off the control circuit of the compressor, and the air-conditioning system stops working.
The air conditioner three-state pressure switch has four lines: two are medium voltage switches, used to control the fan heating fan. The other two are low pressure and high pressure together to control the compression operation.
As shown in the circuit diagram: after the A/C switch inputs the signal to the air conditioner panel, the air conditioner panel will output the signal to the ternary pressure switch (usually a negative signal),The ternary pressure switch detects the pressure inside the pipeline and whether the high and low pressure are normal. If it is normal, the internal switch will be turned on and send the signal to the engine computer board. The computer board controls the compressor relay to pull in and the compressor works.There is also a wire that is normally grounded. When the internal medium voltage of the three-state switch is normal, the switch is closed, and the signal is sent to the engine computer board to control the cooling fan relay to pull in.
