Double oven: fan oven tripping fuse

[moopind]

Hello all and thanks in advance for any advice:

I have an Electrolux double oven (Electrolux EOU43003). I can use the top oven fine, but when I put the fan oven on, it trips the fuse. It starts up and the fan gets going, but after about a second or two, it cuts out and the switch goes on the house's fuse box. If I don't turn the heat up at all, the fan will keep going. Before this happened the first time, there was a burning smell. The oven is not filthy, and the smell was not like a burnt food smell. I don't get any burning smell from using the top oven/grill.

The electric ignition on the separate gas hob above has tripped the electrics for as long as I've had the house, by the way.

I've yet to pull out the cooker, but is there anything obvious that might have caused this? I've swapped out a heating element on a cooker in a previous house, but don't know if that's likely to be the answer this time.

 

[EFLImpudence]

Sounds like the element is faulty.

What exactly is tripping - picture please - just copy and paste.

 

[moopind]

Sounds like the element is faulty.

What exactly is tripping - picture please - just copy and paste.

All of the electrics so I have to reset the RCD (having switched the appliance off).

 

[oldbutnotdead]

The oven problem- either the element has got old and a bit damp or (problem i had) the thermal insulation inside the outer casing has become grease-laden and slighty conductive, in that insulation there are almost certainly bare connectors to elements etc.
Hob ignitor problem- does the rcd trip when you use it (probably grease, water or carbon buildup somewhere causing current flow to ground) or when you power it up (many possibilities)

 

[conny]

I had a similar problem in the house I have recently moved in to.
Fan oven worked, no problem. As soon as we turned the top oven on, (no fan), it would trip the RCD
Electrician come out and tested. Said insulation wa low but just within limits. So he ordered two new elements and fitted one. RCD tripped again. Fitted the second element and tested. All fine. He suggested that damp had gotten into the elements because the top oven wasn't used very often, (my late father-in-law so we know he didn't use the top one).
So, I would be looking at replacing the elements as they seem to be the likely cause. We now make regular use of both ovens.

 

[moopind]

Well, I've fitted a new element today, but there is no difference. Can still use the top oven/grill, but even the fan (with no heat) will trip the RCD after a few seconds. I took the oven out to have a look behind. It was dusty, so I've vacuumed it clean, particulary over the vents, but no difference. There is a bit of damp on the wall (which is an exterior wall in an offshot kitchen in a house from 1900). It's not wet on the appliance though. The cabling from the cooker leads to a bit of a cowboy-looking switch box, which has never been attached to the wall, and is sitting in the cupboard next door, by the baking trays!

 

[Adam_151]

I had a similar problem in the house I have recently moved in to.
Fan oven worked, no problem. As soon as we turned the top oven on, (no fan), it would trip the RCD
Electrician come out and tested. Said insulation wa low but just within limits. So he ordered two new elements and fitted one. RCD tripped again. Fitted the second element and tested. All fine. He suggested that damp had gotten into the elements because the top oven wasn't used very often, (my late father-in-law so we know he didn't use the top one).
So, I would be looking at replacing the elements as they seem to be the likely cause. We now make regular use of both ovens.

I had similar for someone I did a favor for at work, he'd had new kitchen fitted a few years ago, two ovens, only used one, came to use the second and tripping RCD, I just temporalily moved the cirucit onto none RCD side, ran the oven up to temperature for about 20mins, retested was happy that it was at least a handful of meg, put it back on the RCD side, checked it worked, and told him to give it a good go the next day to finish drying it out and try and not leave it unused for extended periods.

 

[moopind]

I had similar for someone I did a favor for at work, he'd had new kitchen fitted a few years ago, two ovens, only used one, came to use the second and tripping RCD, I just temporalily moved the cirucit onto none RCD side, ran the oven up to temperature for about 20mins, retested was happy that it was at least a handful of meg, put it back on the RCD side, checked it worked, and told him to give it a good go the next day to finish drying it out and try and not leave it unused for extended periods.

This sounds way above my skillset!

 

[oldbutnotdead]

Time for some logical faultfinding here.
One scenario is that the oven is only contributing to a L-N imbalance on the group of circuits powered by that RCD. Quite a difficult one to test for (you'd have to disconnect a load of neutrals in the CU) so table it for now.
The wet wall is probably a red herring (given the rest of the oven operates) along with the shoddy termination so again table them for now.
So the fault exists somewhere after the control switch for the fan/lower oven. Unless you've been unlucky and bought a duff element we can exclude that. You now need to expose ALL the wiring between control switch and fan/element and look for the problem. You mentioned a 'burning smell' on the last successful use- that could have been insulation charring or overheating or a bit of food stuck somewhere and again charring.

 

[moopind]

I think this is beyond my skillset. I've looked inside the back panel and can't see anything obviously burned out or exposed. I've taken the element off and fitted it again, in case I'd done that badly, but the same - the cooker runs for a few seconds, bit of a faint smell, then trips the electrics. I don't need to turn the temperature knob up at all - just running the fan (this is on a separate knob) makes it cut out after a few seconds.

 

[GRC]

Time to try replacing the fan motor, or the brushes on the motor ???

 

[SUNRAY]

Time to try replacing the fan motor, or the brushes on the motor ???

Or perhaps disconnect the fan (and make the wires safe) to see if it's the fan motor.