Why does the rapid cycling of a compressor on and off cause it to fail? Rapid cycling can cause a compressor to fail in several different ways. Perhaps one lesser known cause is worn bearings due to lack of lubrication. Each time a compressor starts there is a quick reduction in pressure of the refrigerant/oil mixture within its crankcase. This results in the oil-refrigerant mixture flashing into foam and vapor with the frequent result being that a relatively large percentage of crankcase oil is being pumped out of the compressor.
In order for this oil to return to the compressor, it must travel through the system with the refrigerant and return back through the compressor’s suction port. This oil movement requires the compressor to be in operation. If the compressor is cycled off too quickly, an imbalance is created. Each time the compressor starts, oil is pumped out, but without sufficient run time the oil stays out in the system and does not return to the compressor. This imbalance will lead to a shortage of oil inside the compressor and bearing failure.