According to Heatcraft , a brand new compressor can be ruined because of a faulty contactor or worn contacts. Worn contacts can cause current imbalance or single phasing of the compressor windings, causing irreparable damage to the compressor motor.

Replacing a compressor and not the contactor is like having your car serviced without checking or changing the spark plugs. The perfect time to check and replace the contactor is during compressor replacement.

Your contactor may look fine on the outside but inside it could be a different story. When you remove the outside casing you will probably find burnt out or damaged contacts, meaning the contactor is in desperate need of replacing.

Signs for replacement:

  • Electrical contacts will start to pit and show burn marks
  • The edge will cave in showing that the contact point has been too hot
  • Solidified silver stuck to the contact indicates worn protective coating

Reasons for failure:

  • Contactor is too small for the load
  • Debris between the contactor points
  • Low control voltage at the contactor coil

Danfoss provides a suitable match as it is important that you use the right contactor with the right compressor.