Cooker tripping the electricity

[lumley1]

I have a combination cooker (gas hob, electric oven), we moved into our house about 10 months ago, when I put the cooker in I simply put a plug in it and plugged it into a normal socket.

Last night when tryng to use the oven the trip switch went, on investigation we isolated the problem to the electric oven.

Do I have a fault with my oven or is it because I simply have this plugged in to a normal socket? If it is because it's plugged in why is it just starting to cause this fault now 10 months later?

Many help approciated.

Many thanks.

 

[JohnD]

I am going to guess that you mean the RCD has tripped, due to earth leakage, although you do not say so.

And that you do not mean the MCB has tripped due to a current overload.

The RCD is usually two or three times the width of the other devices in your consumer unit, and has a "T" or "Test" button on it, and is marked "Press T to test, Quarterly" or something like that.

The MCB is probably marked B32.

As your cooker has a gas hob it is possible to plug it in (an all-electric cooker takes too much power to be safely connected through a 13Amp plug).

IF MY GUESS IS CORRECT (and please tell me if not) then the cause is probably slight earth leakage in the cooker. This often happens, especially on the grill and oven elements as they age. For this reason it is usual to have a dedicated cooker circuit that does not go through the RCD. If yours is a fairly modern house or was recently rewired then it is quite likely that such a circuit is already installed but not in use. In this case you will see an MCB marked "cooker" in your consumer unit; an unusually large switch marked "Cooker" in your kitchen and an unusually large cable outlet (not a socket) in the wall near where a cooker might go.

(If you decide to supply the cooker from this circuit, then you need to fuse it near the rated load of the oven, for example with a 13A fuse or a 15A MCB - we can explain this further, it is a common question.)

 

[lumley1]

Thankyou very much for your reply.

Yes according to your description it is my RCD which has tripped and not the MCB (which means nothing to me I'm afraid!).

I'm sorry to say that it is not a modern house and I do not believe I have a MCB (what does that stand for?) marked cooker in my consumer unit and I definitely do not have large cooker switch in the kitchen (we did have one of these in our last house but definitely not one here).

Does this mean that we need some extensive rewiring, to get from the consumer unit (upstairs) to the kitchen? Is this likely to cost me lost of money? I didn't mind doing some DIY but when it comes to electric I am always very weary?

 

[JohnD]

It will probably need a new circuit. As (1) new circuits (2) electrical work in kitchens
are both subject to building regulations, you are better off not attempting it yourself.

Try to get the name of a recommended local electrician from a friend, neighbour or trusted tradesman.

Provided he is a member of one of the approved Self-Certification schemes, he is authorised to perform the tests and issue the documentation himself (if not, you would have to notify your council and pay for inspection and test, as you would if you'd done it yourself).

p.s. An RCD is a Residual Current circuit Breaker, and detects current leaking to Earth. You have probably seen small ones used with lawnmowers as they give some protection against shock with equipment used outdoors or in the wet. An MCB is a Miniature Circuit Breaker, which trips due to overcurrent or short-circuit, and replaces the fuses that were formerly used in fuse boxes. Your Socket Circuits are protected by the RCD as well as their MCBs; this gives protection when you plug in outdoor tools, drop the electric kettle in the sink, or have a fault on your electric shower.