Question 86Refrigeration & AC - QMED

The correct answer is A) An increase in the suction pressure. In an automatically controlled refrigeration system with a pump down cycle, an increase in the suction pressure will cause the compressor to restart. This is because the pump down cycle is designed to stop the compressor when the suction pressure drops, indicating that the system has been sufficiently cooled. When the suction pressure increases again, it signals that more cooling is needed, triggering the compressor to restart and maintain the desired temperature. The other options are incorrect because decreasing the suction pressure (B) would cause the compressor to stop, closing the solenoid valve (C) would also stop the compressor, and closing the expansion valve (D) would not directly affect the compressor's operation in a pump down cycle.