Low Pressure Cut Off In Refrigeration

The cut in value of the low pressure switch is generally set to a saturation pressure equivalent to the minimum expected ambient temperature.

Low pressure cut off in refrigeration.

Kp pressure switches are for use in refrigeration and air conditioning systems to give protection against excessively low suction pressure or excessively high discharge pressure. To protect the compressor against low pressure in the system and to avoid the ingress of air into the system if a vacuum is generated in the lines a low pressure cut out is provided. The low pressure sensor checks that the pressure is not too low in the system which may be caused by a leak in the system which makes the. Since most commercial refrigeration systems work with a coil temperature below 32â f usually between 20â and 25â frost will develop on its coils.

For refrigeration low pressure switch settings a refrigerant pressure temperature chart should be used to determine the cut off for the low pressure side of the system. Referring to the temperature pressure chart the average refrigerant temperature is obtained. The cut in setpoint should be set to a pressure temperature that will allow the evaporator to completely defrost during the off cycle. This should not be confused with the halfway point between the cut on and cut off pressure.

A opposing operational drag b pressure distribution c differential d range. The pressure difference between the system cut in and cut out pressures of a refrigeration unit low pressure cut out device is known as what. Low pressure cut out. The average refrigerant pressure is the pressure of the refrigerant in the evaporator taken halfway through the running cycle as measured on a time basis.

If during the off cycle refrigerant leaks into the low side to raise the pressure to the lpc cut in setting the lpc will start the compressor for a short period until the pressure is lowered to the cut out point and the compressor is once again stopped. When the low side pressure gets to a value that ensures the refrigerant is sufficiently pumped out of the evaporator the low pressure switch will cycle the compressor off. The switches are also used for starting and stopping refrigeration compressors and fans on air cooled condensers kp pressure switches are available in ip 30 and ip 44.