The NATE Industry Competency Exam: Heat Pumps Q&A

The NATE Industry Competency Exam: Heat Pumps Q&A A correct statement regarding the outdoor coil of a heat pump is that damage may result if the: a. Indoor blower fails to operate. b. Defrost water does not drain from the coil. c. Indoor check valve sticks. d. Outdoor metering device sticks open. - CORRECT ANSWER-B If this unit is installed on 208 volts, the transformer primary should be wired: a. To the black and red leads of the transformer. b. To the black and orange leads of the transformer. c. To the red and orange leads of the transformer. d. To the black and brown leads of the transformer. - CORRECT ANSWER-A During the initial startup of a heat pump with a long line set, which of the following is the most accurate method to charge the system? a. Put the unit into the cooling mode and charge it by the superheat method. b. Weight in the exact charge. c. Charge to proper sub-cooling. d. Charge the unit by the superheat method in the heating mode. - CORRECT ANSWER-B A technician has just installed a heat pump. it heats satisfactorily but will not cool. A possible cause of this problem is the: a. Outdoor check valve is not closing. b. Indoor check valve is stuck closed. c. Indoor check valve is stuck open. d. Outdoor metering device is not functioning. - CORRECT ANSWER-C On a heat pump system operating in the heating mode, measurements show a high suction pressure at the compressor. the most likely explanation is a: a. Leaking indoor check valve. b. Loose sensing bulb on the indoor expansion valve. c. Leaking reversing valve. d. Loss of charge in the bulb of the outdoor expansion valve. - CORRECT ANSWER-C A dirty air filter on a heat pump system will result in: