Question 172Refrigeration & AC - 1st Asst/Chief

The correct answer is A) the expansion valve strainers were fouled. If the refrigeration compressor is short-cycling on the low pressure cutout switch, the most probable cause is that the expansion valve strainers are fouled. Fouled strainers restrict the flow of refrigerant to the expansion valve, causing the pressure in the evaporator to drop and triggering the low pressure cutout switch. This stops the compressor to prevent damage. The other options are less likely causes. B) Leaking suction valves would not necessarily trigger the low pressure cutout. C) An overcharged system would more likely cause the high pressure cutout to trip. D) An improperly adjusted high pressure switch would not affect the low pressure cutout.