High Pressure Cutout Switch Operation

The spring is highly compressed now.

High pressure cutout switch operation.

The high pressure cutout switch on the other hand is a safety device only and does not have control of compressor operation under normal conditions. Some pressure switches have a switch or push button for on off control. On some switches it says on off but the words auto off would be more correct. Condenser coils plugged up with dirt and debris.

Operation of a high pressure cut out. It monitors the pressure of the refrigerant on its respective side of the system. What ac pressure switch does. Oil failure switch an oil failure switch is provided with high speed compressors.

When the pressure in discharge line raise above a certain limit of. The pressure switch is set at an high pressure. In refrigeration system the high pressure cut off switch is a control device which is used as safety control. Once the necessary repairs are made to bring the pressure into specification the switch will allow normal clutch.

It has a bellows that is set against a spring. There is a high side pressure switch and low side pressure switch and they both serve to monitor the system for pressure faults that can damage the compressor. When the high pressure gas enters the bellow the bellow expands and presses the spring. The compressor is stopped by cutting the power supply of the motor of the compressor whenever the discharge pressure of the compressor becomes excessive.

Of course an over charge of refrigerant can cause the high pressure switch to open this is especially true with microchannel coils. So really you can look at the ac pressure switch as working in the same way as a fuse in an electrical circuit. If the pressure is too high it could burst the compressor causing a leak of refrigerant fluid. A heavy load in the occupied space adds more super heat to the coil and can cause high pressure readings.

In the auto on position the pressure switch works as expected. The clutch cycling switch measures a c pressure near the evaporator outlet and is often mounted on the accumulator. A simple push of the switch will reset the switch and the operation of the air conditioner should return to normal until the pressure exceeds the rating of the switch. If there is no fluid in the system then it s going to grind to a halt again.

The nut at the end of the spring is used to adjust the cut out pressure. This is necessary to prevent the possible damage of equipment. Things that can cause the high pressure switch to trip include. If the incorrect pressure is sensed the switch will open the a c compressor clutch circuit to prevent operation.

The high pressure cut out as shown in the diagram is of a simple construction. Bad condenser fan motor. Moisture air mixed refrigerants.