Weird oven issue help?

[aerodynamic18]

ok so we have been in our new house for about a week. We were using the oven tonight and the rcd tripped. Ok I thought new element required. I reset the rcd and switched the oven off and then powered everything up again and everything was fine. I then tried the oven one more time and again it tripped. I then left it a while and rang someone about the issue and they are coming on fri( I don’t have the time to do it myself atm) but now I have switched it back on and it’s working fine and heating up but I have no idea what could be going on! Any thoughts?

 

[Deleted member 293381]

The power the oven is drawing could be close to the RCD trip rating.

When you first switch the oven on is the point it draws the most current.

It is a hit or miss situation - sometimes it will trip and other times it won't.

 

[aerodynamic18]

So change the element then ?

 

[Deleted member 293381]

No - the element might be OK, the RCD trip switch might need replacing with a bigger current rating.

Wait for the electrician - he/she will know

 

[aerodynamic18]

I have called in an oven repair person. Should I cancel that and ring the electrician? The fuse box was replaced just before we moved in as it was an old style fuse box ( ie used fuses) and I didn’t want that

 

[SteveCritten]

Sounds like either, oven not on the correct size RCD.....or there is more than just the oven on the said circuit and when the other items are drawing power at the same time as the oven then it’s tripping. They are my theories anyhow.

 

[aerodynamic18]

Weirdly there is a freezer below the oven and they are wired together so u have to leave the oven switch on all the time. We plan to rip the kitchen out and redo it at some stage but need to get it working In the mean time

 

[noiseboy72]

You need an oven repair guy, not a sparkie. You cannot fit a "larger" RCD, domestic ones all trip at 30mA. If it's the breaker for the oven - the MCB, that's a different matter as these will trip on over-current. This still suggests a fault with the oven, as an immediate trip requires around 5X the rated current surge, which is far more than the oven should require when you fire it up. MCBs have 2 trip ratings, surge and over current. A 20A trip might not trip for 30 minutes or more with 30A passing through it and would need 100A or more to trip instantaneously.

Elements are filled with a ceramic insulation material and over time this becomes contaminated and eventually fails. This can cause a partial fault to earth which might sometimes trip the RCD.

Get the element checked - both electrically and physically and I bet a replacement cures the fault. It's less than a hour's work to change the element, so shouldn't be a huge bill.

 

[aerodynamic18]

Thanks. I’ll leave the oven guy coming and report back on Friday

 

[Deleted member 293381]

Yup - I've confused RCD with MCB trip switches.

Apologies.

 

[aerodynamic18]

It’s this first blue switch beside the red one that was tripping. As I said I can turn on the oven now and it appears to be heating ok and the trip stays on. Hopefully just an element

 

[InvisibleDuncan]

Interesting to see that "Test monthly" button on each switch. Does anyone do that?

 

[Pisto_Grih]

If the MCB is tripping, then the freezer thats also wired in with it could well cause the problem? If the oven turns on, and doesn't immediately trip the MCB, but then you open the freezer (perhaps to get out the thing you are planning to put in the oven) and then close the door, the compressor might kick in and overload the circuit?

 

[stiv674]

It's an RCBO, combined mcb and rcd, maybe it only trips when you turn the oven on with the freezer compressor running... combination of both.

 

[Sonic67]

ok so we have been in our new house for about a week. We were using the oven tonight and the rcd tripped. Ok I thought new element required. I reset the rcd and switched the oven off and then powered everything up again and everything was fine. I then tried the oven one more time and again it tripped. I then left it a while and rang someone about the issue and they are coming on fri( I don’t have the time to do it myself atm) but now I have switched it back on and it’s working fine and heating up but I have no idea what could be going on! Any thoughts?

If it's the RCD tripping it's a Live to Earth fault. Or possibly Neutral to Earth, but anyway.

I had it happen once when the cooker had been reassembled, it had been put back together badly and a cable was being pinched by metalwork when a lot of pots and pans were put on the hob.

I went to have a look, everything had been cleared away and the fault was cleared. It wasn't till I stripped it down I found it but until then it was a weird fault that only recurred occasionally.

Sometimes when an element goes you can get this fault.

Oven & Cooker Tripping Problems

But anyway, if it's an RCD you have a fault to earth.

 

[aerodynamic18]

Guy just been. Element replaced as it had leakage to earth. All sorted

 

[aerodynamic18]

Thanks for your help

 

[alphaomega16]

Glad to hear it was nice and simple