Monday, March 20, 2017

Refrigerator Overload Protector Testing Using Multimeter

Today I am writing about the refrigerator overload protector testing using a multimeter. In this post, I will complete guide you about how to test a refrigerator thermal overload protector using a multimeter. As you know that "thermal overload protector" is designed to protect the refrigerator compressor during over current flow. I also published a post about working principles of refrigerator compressor thermal overload protector. The overload protector is connected near the starting relay of the compressor and connects to the compressor common terminal. When the thermal overload protector heats up or makes an open connection internally the compressor stops running. The working of the thermal protector is that to stop the electric supply during the overcurrent flow to the compressor or when the compressor becomes heat up. Sometimes when the ref compressor becomes heat up the thermal overload protector stop the electric supply to the compressor to protect the compressor winding from burning. To learn more about the working of refrigerator thermal overload protector click here.


Also, Read
How a overload protector works
How a ptc realy works 
How to test and wire refrigeator thermal thermostat switch

How To Test Refrigerator Overload Protector Using Multimeter


  • The refrigerator overload protector testing is very easy using a multi meter, to test your refrigerator thermal overload protector follows the below steps.
  • First of all off the refrigerator and plug out the refrigerator supply plug from the outlet, or switch off the double pole circuit breaker from which the refrigerator supply plug controlled.
  • The thermal overload protector is connected or installed near the starting (PTC relay) with compressor terminals. Just remove the relay from the compressor and then remove the compressor overload protector.
  • Remove both wires from the thermal overload protector.
  • Then set your multimeter on connectivity test or diode testing. Connect one testing lead to one terminal of the thermal overload protector and other testing lead to the other terminal of the compressor overload.
  • If you find that there is some connectivity then it means that the overload is alright and working properly. And you don't need to replace the overload.
  • And if you don't see any connectivity then wait for 5 to 10 minutes and then tests the thermal overload protector again. And if still has no connectivity then it means that your refrigerator overload is internally open connection or cut. And you must change the overload protector with a new one with the same range.

Refrigerator Overload Protector Testing Using Multi-meter


Here I try to make you understood using a simple refrigerator overload protector testing troubleshooting diagram. In the below diagram I have shown an Analog multimeter set on the connectivity test, ohm test (resistance testing). And I connect the one testing lead to one terminal of overload and other testing leads to another terminal of the overload. In the diagram, I showed that multi meter showed no reading or no connectivity which means that the overload is not working or internally open.

Refrigerator Overload Protector Testing


In the below 2nd fridge thermal overload protector testing troubleshooting diagram. I showed that millimeter shown the reading and shown connectivity between two points which means that overload is working properly and no need to change.

How To Test Refrigerator Overload Protector



In the above diagram, I have shown and clear that if the refrigerator thermal overload protector has connectivity between two points then it means that overload is working fine. But sometimes if an overload is not tripping or not make an open circuit during overcurrent flow to the compressor then this overload is not a good overload. So the proper method to test your overload compressor starting time and running time current (ampere) and if the overload is not opening circuit during the overcurrent flow then change the overload protector.


Now if the overload is internally open circuit then change and if it has a connectivity between both terminals of overload then test other common places and problems of refrigerator not working. I hope by reading this refrigerator overload protector testing guide, now you will be able to test the fridge thermal overload protector. Be safe and follow all safety rolls before start testing or replacing the thermal overload protector to the refrigerator compressor.

2 comments:

  1. Make one introduction and maintance note on and connection diagram of Air circuit breaker...

    ReplyDelete