Compressor Discharge Temperature Sensor

A refrigerant injection system uses the compressor discharge temperature to protect the compressor from excessively high operating temperatures.

If the vapor injection valve is off and the compressor discharge gas temperature increases to 138 C (280 F), the valve will be turned on.

When the discharge gas temperature decreases to 132 C (270 F), the vapor injection will be turned off unless it is required to be on for other reasons.

The controller immediately stops unit operation if the discharge gas temperature increases to 148 C (298 F). The controller activates the Alarm indicator and records Alarm Code 56 (Compressor Temperature Too High). The controller will restart the unit when sensor temperature is below 90 C (194 F).

      
  1 Compressor Discharge Temperature Sensor
     
     
     
     
     
     
Parent topic: Electrical Maintenance

Replacement

The compressor discharge temperature sensor is mounted externally on the compressor head. To remove:

  1. Shut off power to system.

  2. Disconnect the compressor discharge sensor wires from J4A pin 11 and GRD on the controller.

  3. Cut silicone seal under rim of sensor using razor blade.

  4. Remove old sensor and sensor wires.

  5. Clean sensor seat using wire brush.

  6. Blow out all debris using compressed air.

  7. Apply 0.25 to 0.5 cc thermal grease to mounting position of new sensor.

  8. Add a bead of RTV silicone approximately 5 mm in diameter around area.

  9. Press new sensor into position.

  10. Route the new sensor wires into the control box. Connect wires to J4A pin 11 and GRD on the controller.