Fridge/Freezer tripping RCD every 5 hours

[happypeter]

Hi,

Our Fridge/Freezer is tripping out the RCD switch like clockwork every 5 hours. I reset it and 5 hours later it goes again.

Anyone know what in the appliance could be causing this? Its a fairly new KENWOOD KSBSX17

thanks

 

[YorkshireMidge]

Could be something to do with auto-defrost functionality such as the heater. That comes on periodically on fridge freezers on a timer, to reduce the frost build up.

 

[happypeter]

That makes sense, thanks for the info

 

[Wayners]

Try different socket.

Also pull plug fuse and check it's clean and the seating clips are tight. Bend in a tad to hold fuse tight if needed.
Lose wire in socket can cause trip. I'd prove its appliance by using different socket on different fuse circuit and only then contact warranty.

You can also unplug everything else around or switch off fused spurs.

Sometimes faults can be somewhere else with lose wire or other fault. Maybe 5 hours in fridge plus the fault somewhere is causing trip.


Mate blamed fish tank for tripping electricity and turned out to be kitchen socket bent from uneven tiles causing random trips over several years. Spent money on new fish tank trying to sort. Real headache trying to find faults.

 

[happypeter]

I'd prove its appliance by using different socket then contact warranty

Our consumer unit has 2 RCDs so I plugged it in to a circuit on the other RCD side. Again after 5 hours the RCD tripped.

Didn't think of checking the fuse will give that a try thanks

 

[YorkshireMidge]

That makes sense, thanks for the info

Only thing that doesn't quite make sense is the timing period for the defrost cycle would be a bit shorter than usual at 5 hours - 8 or 12 is more typical so it comes on 3 or 2 times/day. It sometimes says on the timer case what the cycle and operate time is.

 

[happypeter]

Only thing that doesn't quite make sense is the timing period for the defrost cycle would be a bit shorter than usual at 5 hours - 8 or 12 is more typical so it comes on 3 or 2 times/day. It sometimes says on the timer case what the cycle and operate time is.

I've racked my brains to try work out what else could have a 5 hours cycle! I unplugged all other appliances on the circuit.

It has to be the fridge/freezer right? If I tried it on another circuit controlled by another RCD with same result? As wayners said don't want to claim on warranty if its something else

 

[YorkshireMidge]

It seems likely now from what you have said, let's put it that way. The only way you can be sure is to dig it out and do a bit of testing yourself.

Heating elements are one of the main causes of RCD trips. The insulation starts to break down - and you get a tiny leakage current to the outside of the element which is earthed, so the RCD trips. I had an element to change on our oven a while ago. Passed a resistance test to earth when cold, but leave it heating up a while and it would trip. When I dug the element out, which was in the base of the oven and not visible, the outer had actually split.

 

[happypeter]

All the bits and bobs are hidden, don't really want to take the back off while still under warranty.

I've just plugged it into another circuit with nothing else connected, fairly sure it will trip the RCD in 5 hours at 9pm. After it does I'll give currys and claim on warranty.

Didn't even know these things has heating elements so at least learn't something today, thanks for the help

 

[Wayners]

You've done all the right things. Please report back as I'm interested. I don't know if a good thing or bad if it keeps going fine though?

 

[YorkshireMidge]

All the bits and bobs are hidden, don't really want to take the back off while still under warranty.

I've just plugged it into another circuit with nothing else connected, fairly sure it will trip the RCD in 5 hours at 9pm. After it does I'll give currys and claim on warranty.

Didn't even know these things has heating elements so at least learn't something today, thanks for the help

Yeah - it does seem a bit weird and counter intuitive doesn't it? Basic principle here. The timers are electromechanical in older machines and the shortest duration I've found from a dig about is 6 hours (and some generic adjustable ones that go down to 4 hours) - but I can't see a separate timer part listed for your machine which suggests it will probably be electronic, and that might explain why its a bit different. I'd be interested in the outcome too.

 

[Wayners]

Still working OK?

 

[happypeter]

The RCD tripped after about 3 hours this time so who knows what's going on. I have a repair person booked in for Thursday and will update on the out come.

At the moment I have it on a plug timer so it switches off for 15 mins every 2 hours. This seems to keep it working and not trip the RCD. Not ideal but stops it turning off the boiler in the middle of the night and waking up freeeeezing

 

[happypeter]

Could be something to do with auto-defrost functionality such as the heater. That comes on periodically on fridge freezers on a timer, to reduce the frost build up.

Which is exactly what the repair guy diagnosed so hats off to you! It was registering an earth fault.
Cheers guys

 

[YorkshireMidge]

You're welcome. It doesn't take much of an earth fault either - a few tens of milliamps is enough to trip an RCD.

I remember Mrs Midge washing the powder drawer of our washing machine many years ago, and shoving it back in without drying the outside of it. The water dripping off it tracked by capillary action about 18 inches across a join on the front panel and dripped nicely onto the electrics behind. Toasters are probably the very top of the RCD tripping list as a stray lump of crust dropping off the bread and lodging between the element and the earthed body of the toaster makes a very nice carbon resistor if you don't dig it out (that was one I caused!).