Chest freezer tripping earth leakage

What broke or went bang if your chest freezer just started tripping your earth leakage?

Just last night, out of the blue it tripped. Never done this before and we didn’t do anything out of the ordinary such as move it around or got it wet etc.

We’ve had for about 15+ years and did replace the compressor about 6 years ago.

Can a compressor pack up to such an extend to do this?

Want to look at options before I consider buying a new one.

Is the trip instant? As in, every time, immediately? Or is more of a nuisance trip, but it stops happening when you unplug that one appliance?

If I assume the trip is immediate, and you traced it to the freezer, here are the things to check.

  1. Does it stop tripping when you turn off the switch on the wall, or must you unplug it? (this indicates whether the leak is on the live or neutral side).
  2. Does it stop tripping if you plug it into a different circuit (using an extension cord)?
  3. This one is more dangerous: If you temporarily (TEMPORARILY!) disconnect the earth, does it stop tripping? It goes without saying you should not touch the appliance while it is not earthed.

If it stops tripping without an earth connection, you have a definite leak to the body of the appliance, a breakdown in insulation, and you should probably stop using it.

Edit: After this point you need some equipment. I would probably start from the cheapest option to the most expensive.

  1. Test the Earth Leakage itself using an RCD tester (but of course you must have one of those).
  2. Test the insulation between live/neutral and earth on the freezer using an insulation tester (again, you must have one of those).
  3. Test the leakage current on the earth conductor using a clamp meter (you need to have one… :slight_smile: ).

Hi Plonkster, thanks for you quick reply.

It trips the moment I switch on the wall plug. It doesn’t do this is just plugged into the wall socket. I assume this means the leak is on the live?

It does this in other sockets as well. I have tried with an extension cord to three other sockets with the same result.

Yes it is definitely the fridge.

I just now moved it away from the wall to check its specs on the info sticker at the rear, and then plugged it in again to make sure about what you said above. Got to the db and the earth leakage had tripped again. But when I switched it on this time, it stayed on?

So I assume during the movement of the unit something touched or stopped touching something else?

This is the trouble with earth leakage faults. It must trip at 30mA, but it MAY trip from 15mA upwards. So most RCDs trip somewhere between 15mA and 20mA, even though rated for 30mA. In any house there is a bit of leakage, usually to the tune of a few milliamps max, but it could be much higher. Sometimes there is an existing problem that is slowly worsening, but you don’t know about it because it is less than 15mA. Then one day it worsens to the point that it just slightly exceeds 15mA, and now the RCD trips.

That’s when you get these cases where sometimes it trips and sometimes it doesn’t…

I had such a case where nothing was wrong, I just had too much standing loss, and adding a new laser printer pushed me over…

So this issue is not necessarily related to this appliance? More of an accumulation of appliances each with their little contribution?

And the least likely it could be an issue with the actual RCD itself?

Total noob here, just trying to understand.

Yes… but… it appears the freezer itself is a pretty big contributor, since simply switching it off lowers the leakage enough to stop the tripping. I think the point I am making is that the freezer itself might have been degrading for some time. You are now on the brink… which is why you can sometimes manage for the RCD to not trip.

It could be an issue with the RCD, but to be honest, that’s a bit of a hail Mary in most cases (an American football term). If it is that, it is cheap to fix, and the tester is cheap too, which is why I tend to test that first. But RCDs actually don’t fail all that often… I’ve only once had a case where it was actually the RCD (and after replacing it, I opened it up and found tool marks on the inside… a previous home owner had saved himself R300 by “repairing” and putting an old RCD back into the DB…).

What you need is an insulation test on the freezer. The tool used for that test is this:


Edit: In other words, find a sparky with an insulation tester. It’s likely going to cost you a call-out fee and one hour of labour. Depends on the worth of the contents inside the freezer. Alternatively, find freezing space from a neighbour… or shuffle around if you have more than one yourself. You could also hit up marketplace, there’s always someone swinging and old freezer (to tide you over). Finally, I tend to see these things as opportunities to buy that new A+++++++ rated appliance I’ve always wanted… if the budget allows :slight_smile:

I have two different Megger insulation testers available for you to help in your testing, if you need.
Old original English Megger, as well as a newer digital model, like Plonkster showed.

Situated in Valhalla, so let me know and we can arrange.

Thanks, I have a sparky friend and I’m sure he’ll have such a thing. He’s actually coming for a visit this weekend. :slightly_smiling_face:

I have already started shopping for an very energy efficient model yes, as was the case with our dishwasher that gave up the ghost last month. They say these things happens in threes…

But now at least we have time to shop around and prepare for this in next month’s budget hopefully. And we do have extra freezing space available in my camp fridge and the normal fridge but it will be a tight squeeze.

Thanks a lot for the offer Deon!

A Megger I understand to be a unit that provide its own power when testing, and have heard that one should only use such a thing if you know what you’re doing or stuff will break - thus ruling me out lol!

Is a Megger the same thing as an insulation tester?

No problem. Shout if you need to borrow one.

Megger is actually a brand name, like Fluke or Defy, so old timers usually call all insulation/continuity testers Meggers.

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Thanks, good to know.

Pretty sure it’s the compressor

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Maybe it is on its way out. It started working again after I have moved the freezer around, maybe that gave it its last jolt of life.

Will do those insulation tests first when it starts again and take it from there.

When I was in high school, we actually had an old one with a hand crank, in a leather case pretty similar to the one in your photo.

I’ve used my own insulation tester (a gift from Jaco, for which I am eternally thankful) to diagnose an oil heater that tripped the RCD as well. You pretty much put one clamp on the live of the plug, the other on the earth pin, and you measure. Then you repeat for neutral to earth. That cannot possibly damage anything unless it is already damaged. You can also start at 250V, then 500V, sometimes you pick up the problem long before you hit the 1000V max capacity of these meters.

My father in law has one like that! I saw a resemblance in the picture.

Back in school, we had these steel frame desks with wooden seats bolted onto the frame. When you sat on it, you were bound to make contact with the bolts. Your feet were also typically grounded.

What turned out to be great fun was to use one of those old telephone hand cracks and wire it up to the desk frame of the person in front of you and then give it a good crank.

Not entirely sure why the current didn’t stay on the frame of the desk and go to ground that way (electricity isn’t my strong suit if I’ve not mentioned it before) but perhaps it had to do with us all being barefoot back in the day and the desk might have had rubber covers on the bottom of the frame or something like that to prevent it from scratching the floor? Anyways, maybe I’m overthinking it.

The oldest model in my collection is also a hand crank model, but in an wooden box, with a hole in the side for the crank.


At school in the electric class we sometimes had the choice to take the megger or the rod if we did bad in our test.

And then when the teacher was not in the mood for the lesson on that day he would get a smile and say no theory today if we all stand in a circle and can hold hands with the megger and keep it for 10s. He would then start turning that handle slowly, increasing the speed as the seconds pass. What we did just not to learn in school…

You should have learned to carry a piece of fuse wire to short yourself out. Practically invisible.
We spent hours in our electrical theory lab inlaying fuse wire into a knife groove in the long wooden work benches. We’d make it live (220V) way down the other end of the bench.
And have great fun watching our overseer (who like to lean on the bench looking over our shoulders) getting a shock from a wooden bench.

Horrible people you were! :grinning_face_with_smiling_eyes: