Oven Tripping RCD

[nordberg73]

Hi,

Weird one…Around 18mths ago, I had a new consumer unit fitted as well as all new appliances. Everything has been perfect up until a few weeks ago.

One morning, the oven circuit was off, the RCD had tripped. With a bit more investigation, it transpired that the RCD trip coincided with the oven being used, not the hob. Also, the tripping is happening sometime after the oven has been switched off, maybe even hours rather than minutes.

I did some very basic checks - no loose connections either on the oven side or the isolating switch. The oven is connected to a dedicated wall box with 6mm 50 amp cable.

The oven is still under warranty, but I want to rule as much as I can out before going down the hellish route of dealing with Domestic & General…

Any suggestions as to what might be causing this behaviour? I’ve read about the over-rub cooling fan occasionally creating similar issues, but I’m open to any suggestions/guidance.

 

[ericmark]

Seems likely the seals on the oven element have gone faulty, and the hydrophilic nature of the mineral insulation has absorbed water, and it is on the neutral side, and the more the load, the bigger the difference neutral to earth, so more chance it will trip.

To test, there are two tools, neither are likely to be owned by a DIY guy, so not sure how you can test yourself. Do you know anyone who can test it for you?

 

[nordberg73]

Thanks.the oven is still under warranty, so if it’s likely to be the oven itself rather than anything environmental (I appreciate there’s no certainty at the moment), I’m happy to explore that route..

 

[Harry Bloomfield]

One morning, the oven circuit was off, the RCD had tripped. With a bit more investigation, it transpired that the RCD trip coincided with the oven being used, not the hob. Also, the tripping is happening sometime after the oven has been switched off, maybe even hours rather than minutes.

Is the oven the only item on the RCD, or might it be a RCBO which is tripping, for the oven circuit? An RCBO is a combined RCD + MCB, in the single device.

 

[jj4091]

Make and model always helps but if you have an extended warranty leave it up to them. It could be any one of a variety of problems but as Eric said the element is the favourite thing to cause tripping.

 

[nordberg73]

Sorry, I’m not au fait with the terminology.. It’s a new consumer unit with a dedicated circuit for the oven and hob (the hob seems to not be part of this issue as it’s never been one when it’s happened).

 

[nordberg73]

It’s a new HiSense single built in oven.

 

[Harry Bloomfield]

Sorry, I’m not au fait with the terminology.. It’s a new consumer unit with a dedicated circuit for the oven and hob (the hob seems to not be part of this issue as it’s never been one when it’s happened).

Does the thing which tripped, only supply the oven, and also have a button marked T or test?

 

[nordberg73]

Yes, the circuit is purely for the oven and hob. It doesn’t have a button as far as I remember, just a switch.

Edit - having Googled it, I’m pretty sure the circuit is on a MCB rather than RCD..

 

[Harry Bloomfield]

Edit - having Googled it, I’m pretty sure the circuit is on a MCB rather than RCD..

Post a photo of it, so we can be sure. An MCB tripping, might be more involved than the element failing.

 

[nordberg73]

Ok. I’m not there again until later in the week.

One thing worth mentioning is that when I pulled the oven out to check be cable, there was a slight kink in the cable (it’s the 6mm flat cable, the same as what goes back to the isolator and consumer unit, so it’s not especially flexible). I’m guessing it got “bent” when the oven was slid into the kitchen unit.

The cable felt fine, didn’t feel as though there was any weakness or a break where the kink was. I made sure it went back in correctly when I refitted the oven into the unit.

Could be nothing, but mentioning it anyway. I was going to get a couple of metres of the round 6mm flex to put in its place, just in case…

 

[ericmark]

The same meter will show overload or earth leakage, ⁣but used differently, it seems likely you need an electrician, sorry.