A thermal-electric (solid state) expansion valve is controlled by

A thermal-electric (solid state) expansion valve is controlled by

• A. ambient humidity
• B. motor position
• C. NTC pressure
• D. mechanical linkage

Answer: (C)

Electronic expansion valves regulate flow through a closed control loop that uses a sensing element to determine how much refrigerant is needed. A solid-state valve typically uses an NTC sensor to monitor evaporator conditions (temperature, which ties into pressure via the refrigerant’s saturation relationship). The controller converts that sensor signal into a drive command and moves the valve to the appropriate opening using a small motor. So the valve’s regulation is driven by the signal from the NTC-based pressure/temperature sensing, not by ambient humidity or a purely mechanical linkage. The motor position is simply the actuator response to that control signal.

Electronic expansion valves regulate flow through a closed control loop that uses a sensing element to determine how much refrigerant is needed. A solid-state valve typically uses an NTC sensor to monitor evaporator conditions (temperature, which ties into pressure via the refrigerant’s saturation relationship). The controller converts that sensor signal into a drive command and moves the valve to the appropriate opening using a small motor. So the valve’s regulation is driven by the signal from the NTC-based pressure/temperature sensing, not by ambient humidity or a purely mechanical linkage. The motor position is simply the actuator response to that control signal.