Question 81Refrigeration & AC - 1st Asst/Chief
70% to passIf a refrigeration compressor were short cycling on the low pressure cutout switch, what is the most probable cause?
Athe high pressure switch was improperly adjusted
Bthe system was overcharged with refrigerant
Cthe expansion valve strainers were fouled
Dthe suction valves were leaking slightly
AI Explanation
The correct answer is C) the expansion valve strainers were fouled. If a refrigeration compressor is short cycling on the low pressure cutout switch, the most probable cause is that the expansion valve strainers are fouled. This restricts the flow of refrigerant through the expansion valve, leading to a sudden drop in suction pressure and triggering the low pressure cutout switch. The other options are incorrect because: A) the high pressure switch adjustment would not affect the low pressure side, B) an overcharge would typically lead to high pressure issues, not low pressure, and D) slight suction valve leakage would not cause such dramatic pressure drops.
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