Crankase Heater In screw Compressor

[MayankBhatia]

HI everyone..Im a newbie in A/c i have heard many a times that while the compressor is off the crank case heater should be ON.Mainly in Cold day.Can somebody explain the pros and cons of it..?

[The Viking]

First of all we need to understand that whilst it is fairly easy to compress gas it is impossible to compress liquid.

Now, in a system with no circulation (for example when the compressor is switched off), unless otherwise prevented the liquid refrigerant will migrate to the coldest part of the system. At certain circumstances refrigerant in it's gas phase will also change in to liquid/gas mixture.

As the compressor not are able to compress liquid it will break if too much liquid enters it, it is therefore important to ensure that the compressor never is the coldest part of the system whilst there is no refrigerant flow as it otherwise can try to start with a crankcase full of liquid.

This is the job of the crankcase heater - to ensure there isn't liquid migrating to or forming in the crankcase.

Hence, Compressor OFF = Crankcase Heater ON and vice versa (As it isn't needed when the compressor is running and it will break down after X hours usage).




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[Gary S]

First of all we need to understand that whilst it is fairly easy to compress gas it is impossible to compress liquid.

Now, in a system with no circulation (for example when the compressor is switched off), unless otherwise prevented the liquid refrigerant will migrate to the coldest part of the system. At certain circumstances refrigerant in it's gas phase will also change in to liquid/gas mixture.

As the compressor not are able to compress liquid it will break if too much liquid enters it, it is therefore important to ensure that the compressor never is the coldest part of the system whilst there is no refrigerant flow as it otherwise can try to start with a crankcase full of liquid.

This is the job of the crankcase heater - to ensure there isn't liquid migrating to or forming in the crankcase.

Hence, Compressor OFF = Crankcase Heater ON and vice versa (As it isn't needed when the compressor is running and it will break down after X hours usage).




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well put viking