Electric oven

[DaveHM]

Every now and again the switching of the oven thermostat causes the
RCD on the consumer unit to trip. I think this is caused by arcing on the
thermostat causing a transient that exceeds the RCD rating. Question is
should I go for a new RCD or oven thermostat?

 

[JohnD]

And perhaps it is nuisance tripping. Is this a 30mA RCD or a 100mA one? Why is the cooker on an RCD - it is not usually considered appropriate?

 

[Steve]

Why is the cooker on an RCD - it is not usually considered appropriate?

except when the CCU has a socket and the cooker is in a ground floor kitchen . . .

 

[JohnD]

Grrr, socket, just encourages people to drape the kettle lead across the hob.

 

[DaveHM]

And perhaps it is nuisance tripping. Is this a 30mA RCD or a 100mA one? Why is the cooker on an RCD - it is not usually considered appropriate?

The rcd is part of the consumer unit main switch- so its looking at all circuits-. It is a Hagar unit and is rated at 30mA.
It is very much a nuisance!
There is a rating of 100A on the RCD.

 

[JohnD]

Do you mean the main switch is 100A and it has a 30mA RCD as well? So it would be a split-load unit. A few minutes tinkering by a suitably qualified electrician could move the cooker MCB to the non-RCD section.

 

[ban-all-sheds]

I think this is caused by arcing on the
thermostat causing a transient that exceeds the RCD rating.

Arcing is not the same as earth leakage.....

 

[Har_vey]

Every now and again the switching of the oven thermostat causes the
RCD on the consumer unit to trip. I think this is caused by arcing on the
thermostat causing a transient that exceeds the RCD rating. Question is
should I go for a new RCD or oven thermostat?

The element would be more prone to developing faults. You would be better getting someone to test before replacing anything.

 

[DaveHM]

I think this is caused by arcing on the
thermostat causing a transient that exceeds the RCD rating.

Arcing is not the same as earth leakage.....

I know, arcing's a phenomanum that involves lots of current

 

[DaveHM]

Every now and again the switching of the oven thermostat causes the
RCD on the consumer unit to trip. I think this is caused by arcing on the
thermostat causing a transient that exceeds the RCD rating. Question is
should I go for a new RCD or oven thermostat?

The element would be more prone to developing faults. You would be better getting someone to test before replacing anything.

Presumably you mean that when the element gets hot then there would be a neutral to ground, I thought of this and did some measurements but could not find a problem.
Nice to get all this response.

 

[JohnD]

Don't look at me, I wouldn't recognise a transient if it fell on my head

 

[DaveHM]

Do you mean the main switch is 100A and it has a 30mA RCD as well? So it would be a split-load unit. A few minutes tinkering by a suitably qualified electrician could move the cooker MCB to the non-RCD section.

Its a double oven & the top one works fine. The problematic bottom oven can go days without problem. Hav'nt got around to examining the inner workings of the cu.

Incidentally this problem started after an oven cleaning session, must be a clue there somewhere.

 

[DaveHM]

Don't look at me, I wouldn't recognise a transient if it fell on my head

transients a spike when something switches on and off. Thanks for your input.

 

[Har_vey]

Don't look at me, I wouldn't recognise a transient if it fell on my head

yeah you would. lots of people drive em. normally white.

dave. what make is the oven? how many elements are in circuit when the fault shows? is it possible to disconnect one and check the other? I have seen faulty thermostats, but it's usually the element, and if it's only the cooker then it is unlikely to be the rcd.

Incidentally this problem started after an oven cleaning session, must be a clue there somewhere.

have a look at the capillary tube that is in the oven compartment which is part of the stat. See iff it is damaged?

 

[securespark]

Incidentally this problem started after an oven cleaning session, must be a clue there somewhere.

Leave it to dry out for a few days if it has got wet, then try switching on.