Expansion valve controllers
What is the expansion valve controller?
The electronic expansion valve controller or expansion valve driver is actually a microprocessor controller to control the on/off position or setting accurate steps of electronic stepper motors in electronic expansion valves. The expansion valve controller usually be used in three applications; Superheat control, Temperature control and Pressure or Mass flow control.
Superheat controller
in this application, expansion valve controller duty is measuring the pressure and temperature of the suction line, calculates the superheat and after comparing it with the set point, opens or closes the command to reach the exact superheat amount. Superheat controllers need a pressure transduce with voltage or current output (0-5V or 4-20mA is most common) and a NTC, PTC or Pt1000 temperature sensor that are placed on suction line.
Temperature controller
An expansion valve controller can be used as temperature controller in some applications. Actually, it is an ON/OFF thermostat that opens/closes the stepper valve or modulating thermostat that regulates temperature according to a reference point.
Pressure or Mass flow controller
The electronic expansion valve driver can be designed for pressure control applications such as evaporator pressure regulation, condenser pressure regulation, hot gas bypass line and another one. The driver needs an analog input signal usually 0-10V or 4-20mA to regulate pressure or mass flow in accordance with the analog input.
Among the popular expansion valve driver and superheat controller we can mention Dixell IEV22D & IEV24D, Danfoss EKE 1A,EKE 1B & EKE 1C and Carel EVD twin controllers.
Aljebal, supplier of all Danfoss, Dixell and Carel Superheat controller and electronic expansion valve Driver in Dubai, UAE.
