NATE ICE Heat Pump questions and answers 2023

A correct statement regarding the outdoor coil of a heat pump is that damage may result if the: defrost water does not drain from the coil. A dirty air filter in a heat pump operating in the heating mode could result in: excessive head pressure. A dirty air filter on a heat pump system will result in: high head pressure in the heat mode and low suction pressure in the cool mode. A fan delay can add cooling efficiency by: operating the indoor blower after compressor shut-down A heat pump that uses a piston-type metering device on the indoor coil has a piston with a larger-than-recommended orifice. This will result in: low head pressure and high suction pressure in the cooling cycle. A new 3-ton heat pump installation has an undersized return air duct. In the heating mode, the unit will most likely: go off on high pressure safety. A technician has just installed a heat pump. It heats satisfactorily, but will not cool. A possible cause of this problem is the: indoor check valve is stuck open An electric furnace has four 5-kW elements that are rated at 240V. The available voltage to operate the furnace is 208V. Which of the following indicates the effect that this will have on the BTUH output of the furnace? it will reduce the BTUH output of the furnace. An electric furnace is controlled by a single-stage thermostat. On a call for heat, all connected circuits function properly; however, the heat rise across the furnace is much lower than design requirement. Which one of the following actions should the technician take to correct this problem? reduce the air volume through the furnace Coefficient of Performance (COP) is used primarily in the heating/cooling field to compare heat-pump efficiencies to those of: electric heating units. 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? put the unit into the cooling mode and charge it by the superheat method If the reversing valve were to stick in the halfway position, which one of the following would service gauges indicate? low discharge pressure and high suction pressure In an air-to-air heat pump in the cooling mode, the compressor runs, but the outdoor fan does not operate. There is nothing wrong with the fan motor or capacitor. Which of the following is most likely faulty? defrost relay 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: leaking reversing valve. On a heat-pump system, the accumulator is installed: in the suction line just before the compressor. On an all-electric heat pump system with a single-stage compressor, the thermostat second-stage heating contacts serve to: energize the auxiliary heaters along with the compressor. Temperature checks at the connections of the reversing valve will indicate: reversing valve leakage. Using the diagram above, if a heat pump compressor fails and requires clean-up, a suction line filter-drier should be temporarily installed: between 14 and 15. Using the diagram above, if this unit is installed on 208 volts, the transformer primary should be wired: to the black and red leads of the transformer What happens to the outdoor fan when the heat pump goes into a defrost cycle? it is de-energized When a heat pump is in the cooling mode of operation, the check valve at the indoor coil is: closed Which of the following components is unique to heat pumps? reversing valve Which of the following shuts off when the heat pump is in defrost mode? outdoor fan With the system operating in the heating mode, only high pressure superheated vapor will be present between which of the following points? 13 and 8