NYC RMO EXAM, CHAPTER 20 (Controls)
questions with verified answers
20.01.) Which of the following voltages is often used in control systems? Ans✓✓-
24 v
20.02.) Solenoid valves are actuated by which of the following power sources?
Ans✓✓-Electromagnetic
20.03.) In the "pump-down control system" the thermostat should be wired in
series with which device? Ans✓✓-Solenoid valve
20.04.) A mechanism for automatically stopping the operation of the "pressure
imposing element" is a? Ans✓✓-Pressure limiting device
20.05.) In reference to the solenoid valve used in basic control systems, when
current flows through the valve what position will it be in? Ans✓✓-Open
20.06.) If there is a sudden cold front, a space thermostat will cause the solenoid
valve to? Ans✓✓-Close, pumping the evaporator down, shutting the system off
on low pressure
20.07.) Which of the following devices is not used to regulate the flow of
refrigerant to the evaporator? Ans✓✓-Solenoid valve
20.08.) Which of the following conditions will cause a system's compressor to
pump down? Ans✓✓-A decrease in space temperature
questions with verified answers
20.01.) Which of the following voltages is often used in control systems? Ans✓✓-
24 v
20.02.) Solenoid valves are actuated by which of the following power sources?
Ans✓✓-Electromagnetic
20.03.) In the "pump-down control system" the thermostat should be wired in
series with which device? Ans✓✓-Solenoid valve
20.04.) A mechanism for automatically stopping the operation of the "pressure
imposing element" is a? Ans✓✓-Pressure limiting device
20.05.) In reference to the solenoid valve used in basic control systems, when
current flows through the valve what position will it be in? Ans✓✓-Open
20.06.) If there is a sudden cold front, a space thermostat will cause the solenoid
valve to? Ans✓✓-Close, pumping the evaporator down, shutting the system off
on low pressure
20.07.) Which of the following devices is not used to regulate the flow of
refrigerant to the evaporator? Ans✓✓-Solenoid valve
20.08.) Which of the following conditions will cause a system's compressor to
pump down? Ans✓✓-A decrease in space temperature
