11 Multiple Choice 2 points What is indicated by a reading of 120 volts across the terminals on a line voltage thermostat on a commercial refrigerator that is connected to a 120-volt power source? O The thermostat is closed The thermostat is open The compressor is faulty 120 volts is being supplied to the compressor 12 "Multiple Choice 1 point What function will the controls of an air source heat pump need to periodically perform during heating operation? All of the choices are correct Defrosting of the indoor coil Defrosting of the outdoor coil Defrosting of the compressor 13 Multiple Choice 1 point When troubleshooting a switch to determine if it is malfunctioning, the technician must know the of the switch in the system O Layout Function Off position resistance Location 14 Multiple Choice 2 points Which of the following functions is performed by the defrost control during a defrost cycle on a heat pump? Energize the supplementary heating Switch the heat pump into the cooling mode of operation by controlling the reversing valve All of the choices are correct De-energize the outdoor fan motor 15 Multiple Choice 2 points What is the likely cause of a PSC condenser fan motor that will not start in a residential condensing unit if the compressor operates, and the fan motor is warm to the touch? Shorted compressor winding Faulty capacitor O Open contactor coil O Open transformer winding