Question 193Refrigeration & AC - Assistant Engineer

The correct answer is D) discharge relief valve leaking back to the suction side. In a properly functioning refrigeration system, the discharge pressure should be higher than the suction pressure. If the discharge relief valve is leaking back to the suction side, it would allow high-pressure refrigerant from the discharge side to flow back to the suction side, resulting in both low discharge pressure and high suction pressure simultaneously. The other options are incorrect because: A) improper superheat adjustment would not cause both low discharge and high suction pressures; B) a fouled condenser would result in high discharge pressure and low suction pressure; and C) an overcharge of refrigerant would typically result in high discharge and suction pressures.