# How we recharge oil in compressor of a refrigerator



## sindbaad

Hello friends,

Changing oil of crankcase is a pretty simple task. But how to change the oil that is present in the compressor of referigeration system.


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## surfaceblow

The first step is to find out if the system uses a sealed unit or a standard compressor with a separate motor and proper valves? 

A sealed unit you have to reclaim and purge the system, check for leaks then pull a vacuum before putting the oil and refrigerant back into the system. The oil and refrigerant charge would be on the nameplate of the unit. The charge should be done on the discharge side of the unit.

You also have to do the paperwork on the amount of gas reclaimed and amount gas put back into the system.

Joe


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## sindbaad

Thanks surfaceblow for this piece of information.


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## bones140

Surfaceblow is correct with regard to the reclaim and subsequent recharge if the system has a large hermetic compressor. For fractional horsepower compressors it is almost impossible to get all the oil out without cutting the compressor open. Large hermetic compressors normally have an oil level sightglass which makes it a little easier. Semi hermetic or open drive compressors have a drain plug to enable oil change. With a small hermetic the complete refrigerant charge will have to be recovered. On larger hermetic and semi or open drives there will be suction and discharge valves which will allow the compressor to be pumped down or isolated. The oil should be introduced into the crankcase prior to the system or compressor being evacuated. Refrigerant charging is dependant on the type. Some blends can only be charged in the liquid state and as such care should be taken to prevent compressor damage. This is a very brief description and does not go into dryers etc. The question is why do you need to change the oil? If the system has not been opened then the oil will be okay.


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## engineer64

In the RN oil for fridge compressers came in sealed cans, any oil remaining in the can after use had to be discarded to prevent any contamination by moisture.


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