installing an electric cooker

[docbones]

Hi Folks,
We've been given an one year old electric cooker to replace an old gas one that died. The cooker is a single oven type and the label on the rear says it is rated at 9.3/10.1Kw
We already have a radial circuit etc. for an electric cooker which was there when we arrived. This has a 30A breaker fitted. It seems to me that this probably won't be high enough (9300/230=40) for the cooker but as it is only a single oven type it seems odd to me that it would need any more than a standard 30A. so, a couple of questions:
1) Would i get away with wiring this into the 30A circuit as long as we didn't use everything together? Would it just keep tripping the breaker or would it be dangerous?
2) If i do need a 45A breaker how straightforward is this to fit into the consumer unit (do they just unplug?) and do i need a particular type?
3) Am i going to have problems with the wiring size if i uprate the breaker? I can't easily get to any of the wiring as it is all sunk into the wall.
I would be grateful of any advice. The cooker was free and we don't really have the money to get someone in to install it and we're fed up with microwave meals!
Cheers, John

 

[JohnD]

As you say you have a 30A breaker I am going to guess it is an old Wylex Standard CU. this is obsolete and not as good as a more modern one.

You generally can't put any breaker bigger than 30A into them (a picture of yours will help)

Also the cable for the circuit will have been installed with that load in mind and is probably not safe for more.

Changing a circuit in a kitchen is notifiable work but will be a good thing to do when funds permit. An electrician who is a member of a self-certification scheme could install a big cooker circuit, plenty of sockets, and an extra circuit for the freezer. Don't refit your kitchen before having this done as it will spoil decoration and tiling.

If you put a big cooker on an undersized breaker, it will not trip very often. Most likely at Christmas when you are cooking a big meal and have all the rings on at the same time. If it ever does trip, turn all the rins off, turn them back on one at a time. Do not turn on the next ring until the preceding one is fully hot (once they are hot, they take less current as the current is turned on and off to maintain the temperature. When turned on from cold they take full power until hot). Preferably never have all the rings and the oven on at the same time. The oven typically takes about 10Amps so of this is off it brings the load down to 30A or less.

If anyone offers you a cooker with a gas hob and electric oven, that is the best sort to have!

 

[luminaire]

With your cooker rated at 10.1kW, and taking diversity into account then that gives 20.17A +another 5A if your CCU has a socket included. Therefore 30A should suffice.