RCD problem

[DW2]

I have a SMEG cooker and the element for the fan oven is continually failing after about a year. SMEG service have replaced it once foc but the second time they have charged for labour £55 + VAT.

I asked the engineer why this element failed so often and he said that it was becuse it was on a RCD protected circuit. I have a board where the power circuits are all RCD while the others are not. It is feasible to get it changed?

 

[Adam_151]

Is the element actually failing, or just tripping the RCD?

An RCD cannot cause an element to fail, but if an element goes 'leaky' then it'll start to trip and RCD whereas it'd function perfectly well on a non RCD circuit

Theres not specific requirement to RCD cookers, but when BS7671:2008 comes into force in June, it might be difficult to get away from it.

At the moment, if it has a socket on that might be used to plug an extension lead for outside stuff in, then it needs to be on an RCD, the new standard requires RCD if it has a socket on at all and/or the cable is run unprotected in the wall

(though there is a possibly that your supply is TT, picture of board and metering area would help identify supply earthing type)

 

[DW2]

Thanks for the advice. The element is actually failing after some 11 months each time. The house was newly built and completed some 6 years ago. The box has the power trips on one side and the lighting trips on the other. When the element fails the main trip for all the power circuits drops out and it cannot be returned for some minutes.

 

[JohnD]

so you mean the element is still in working order, but it trips the RCD, right?

This is quite common on heating elements as they age. Without knowing what the leakage is on your oven, I don't know, but often you have several small leakages in the house, maybe adding up to 15mA but varying, and the extra leakage from the oven is oven to reach the tripping point.

One way round it (if this is actually the case) is to take the oven off the main RCD, and put it on an RCBO (at extra cost, maybe in thh region of £30-£40 for the part, plus an electrician's time to make the change and test it).

Until recently, it was preferred to put electric cookers on a non-RCD circuit, because they tend to cause nuisance tripping. in this case, the cooker switch should not incorporate a socket outlet. But in future, it looks like all new installations will have RCDs for everything (I exaggerate to simpliffy)

 

[DW2]

No it is the element that has failed each time amd the trip for all the power circuits drops out. Initially it cannot be reset but after some 10 minutes it can be switched back on. Replacing the element costs some £30 plus the engineers call out of £65. All very expensive.

 

[JohnD]

What do you mean by "trip for all the power circuits drops out"

what does it say on the device that trips? (All the words and numbers please)

 

[DW2]

The label beneath the trip says RCB controlled circuits. Beneath the trip is RCCB 230v im 1500A REC1008.1

 

[JohnD]

It doesn't say "30mA" or "0.03A" or "100mA" or "0.1A"?

No maker's name?

and does it have a button marked "T" or "Test"?

I'm talking here only about the plastic device that trips, about two inches wide.

 

[DW2]

Maker's name is HAGER CD284U. There is a test button alongside the main trip and above it is 164 355 100A 0.03A

Hope this helps but it is in a very restricted position.

 

[dingodeano]

this the blighter? click link > http://www.gil-lec.co.uk/custom/upload/images/products/2/400x400/cd284u.jpg

The box has the power trips on one side and the lighting trips on the other.

And when this switch ' trips' you loose all of your sockets and lighting in your house so you loose all of your electricity? if not what remains. Are you supplied by overhead cables. or are you aware of an earth electrode outside your house?

 

[DW2]

Yes that is it.

 

[Taylortwocities]

It sounds like you have just one 30mA RCD to protect the whole of your house & that aint right.

We do need a photo of your incomer and your fuseboard including the RCD that trips.

 

[dingodeano]

EDIT <> Read back through .

 

[DW2]

Dingo deano

When the trip goes out only the power goes off. House is fed by underground cables and there is no other impediment that I know of.

 

[DW2]

Trying to find ouy how to add a photo. Can anyone help please?