When the condenser gets linted or when the condenser fan becomes sluggish or totally inoperative, the head pressure (high-side pressure) goes up because the condenser is no longer able to dissipate heat from the refrigerant into the surrounding air. The unit loses its cooling capacity and runs continuously as the temperature control never becomes satisfied. The compressor overheats to the point where the overload protector, sensing the abnormal heat, shuts it down until it cools enough to allow a restart. A dirty condenser is a common cause of compressor short-cycling (cycling on overload).
