Samsung fridge freezer tripping electrics

[tommoooo]

Hi there,

Hoping someone more knowledgeable than myself might be able to give me some ideas.

I have had a Samsung RS7527BHCBC_BK for around 6 years. On Friday night it started tripping the RCD. Had a Google and noticed defrost heaters seem to be a common cause with these. I managed to get to the defrost heater and tested the resistance with the multimeter, I got a reading of 249 with the meter set at 200 Ohms. This seems to be higher than expected but apparently still in acceptable range?

Anyway, being non the wiser if this was good or bad, i started the fridge up but leaving the defrost heater disconnected. I checked regularly and the freezer was starting to get colder and build up frost on the onsite, all was looking good, then around 6/7 hours later the RCD tripped again.

I am still tempted to order a replacement defrost heater. Before I do, any ideas?

Thanks,

Tom

 

[jj4091]

RCDs can trip with neutral or live to earth. The fact that it worked when disconnected does suggest the element is faulty in a way that would not show using a multimeter but probably would with a proper insulation tester. Did you disconnect live & neutral or just one leg of the wires to the element? If you disconnected both then perhaps the wires to the element are shorting to earth through any ice build up.

 

[ericmark]

It needs testing with an insulation tester not a multi-meter, it needs at least 250 volt, normally we use the 500 volt range. If it shows so low with a multi-meter then it needs replacing. Even when showing infinity with a multi-meter they can still fail with a proper meter.

 

[hllns]

Is it the only device fed from the RCD that's tripping? No other potential sources of leakage?

 

[tommoooo]

Thanks for your responses here.

When the electrics trip it takes out the whole 'bank' of breakers, I have two banks. I moved the fridge/freezer to a socket on the other bank of breakers, the same problem was apparent, after a while it tripped the whole bank.

I disconnected the defrost element from both ends of the connection, shown below. As above, this tripped after a few hours.

Thanks!

 

[hllns]

If the element is definitely disconnected at both ends I'm struggling to see how it's that, it's a huge Fridge Freezer, is there another element anywhere else?

It leaves you with the cooling bit and any control systems, the fact you can get PCBs for these on eBay is "interesting" but needs further diagnosis before I'd consider swapping any of that.

 

[jj4091]

Have you checked the mains lead for mechanical damage & the suppressor it is connected to internally, I feel it would be unusual for a circuit board to trip an RCD without showing some obvious sign of burning at a component or track.

 

[tommoooo]

If the element is definitely disconnected at both ends I'm struggling to see how it's that, it's a huge Fridge Freezer, is there another element anywhere else?

It leaves you with the cooling bit and any control systems, the fact you can get PCBs for these on eBay is "interesting" but needs further diagnosis before I'd consider swapping any of that.

I didn’t see any other element, I suppose there could be one on the fridge side?

My thoughts were that if it was the element(s) it would short out sooner, as they’d come on as soon as the fridge is powered (from room temp)?

I did take the back panel off, it was clogged heavily with dust, have cleaned that out and trying again….

 

[tommoooo]

Have you checked the mains lead for mechanical damage & the suppressor it is connected to internally, I feel it would be unusual for a circuit board to trip an RCD without showing some obvious sign of burning at a component or track.

Yes, that all looked fine far as I could tell

 

[tommoooo]

I did take the back panel off, it was clogged heavily with dust, have cleaned that out and trying again….

Good news!

This seems to have fixed it, almost 36 hours with no issues.

Thanks to anyone who helped out!