Why won't the compressor or condenser fan on my test chamber start?

There could be a number of causes including a blown fuse in the mainline or in the compressor circuit, a defective refrigeration switch, a defective power relay in the refrigeration circuit, and more.

Check out these possible causes and solutions when your unit is connected to a suitable electrical system, the compressor and condenser fan are not connecting:

  • A blown fuse in the mainline or in the compressor circuit.
  • SOLUTION: Locate the source of the overload and replace the fuse.
  • A defective refrigeration switch.
  • SOLUTION: Replace the defective switch.
  • The refrigeration circuit has a defective power relay.
  • SOLUTION: Replace the defective part with an equivalent relay.
  • The off/on, high/low or pressure switches (if equipped) have cutout. 
  • SOLUTION: Push the button on the individual controls to reset. Also, check the cause of the pressure cutout.

 

Check out these possible causes and solutions when your unit is connected to a suitable electrical system, the condenser fan is operating but the compressor is not:

  • Low line voltage or your system is attempting to operate on inadequate wiring.
      SOLUTION: If your voltage is low, install a booster transformer. If low voltage occurs only when other loads draw excessively, try connecting the unit to another line which is not overloaded.
  • The compressor is off due to an internal overload.
      SOLUTION: Examine the compressor to verify proper voltage supply.
  • There is an open circuit in wiring to the compressor.
      SOLUTION: Locate the open circuit and repair.
  • The compressor(s) current relay is defective or there is an internal thermal overload.
      SOLUTION: Replace the defective part.
  • The compressor is defective.
      SOLUTION: Replace the compressor.