pressure switch hvac

The air conditioning pressure switch belongs to an important component in the air conditioning product，It could protect the product from overload due to excessive pressure , and can be automatically reset.But ordinary air conditioners are often not equipped with air conditioning pressure switches in order to save costs,Only some special air conditioner equiped.For example, large computer room air-conditioning  need to be equipped with pressure switch to protec refrigeration system.Today will introduce and the related principle as well as the concrete location information.

1: Principle of air conditioning pressure switch
 When the pressure in the system is higher or lower than the rated safe pressure, the disc in the sensor moves instantaneously, and the switch joint is connected or disconnected by connecting the guide Rod,When the pressure drops to or  rise to rated recovery value, the disc is instantly reset, the switch is automatically reset.
Or simply, when the measured pressure exceeds the rated value, the free end of the elastic element displacement, directly or after comparison to push the switch element, change the on-off state of the switch element, to control the measured pressure.The elastic element could be the single coil spring tube, the diaphragm, the bellows and so on.

2:Function of hvac pressure switch

The pressure switch of the air conditioner plays a protective role. When the pressure in the air-conditioner pipeline is too high or too low, the switch action will change the on-off state of the control element and protect the air-conditioner from damage.

3: position of  air conditioning pressure switch
Generally unit less than 5 units will not  add pressure switch,Pressure switches are generally used in 5 or more Frequency conversion unit or frequency air conditioning units.The pressure switch is installed in the pipeline near the exhaust port and the return port of the compressor,The one installed at the exhaust port is called a high pressure switch.For R410A refrigerating unit, the set value  is always 4.15 MPA on and 3.15 MPA off.The pressure switch installed at the return port of the compressor is called the low pressure switch. The protection setting value is about 0.1 MPA.

In addition to the pressure switch, the compressor itself also has a heat protector, the heat protector will disconnect and the compressor stops working If the compressor overheats,There's also a temperature sensor, which senses the temperature, and when reach the setted temperature, the compressor loses power.All of these are designed to protect the compressor and refrigeration system