Which of the listed operations will cause an automatically controlled refrigeration compressor to restart if the system features a pump down cycle?

Correct Answer: Option C — An increase in the suction pressure

During a pump-down cycle, the compressor evacuates the low side until suction pressure drops enough to trip the low-pressure switch. An increase in suction pressure, caused by a temperature rise or liquid feed, overcomes the cut-in setting and restarts the compressor.