Replacing electric cooker with built-in hob and oven

[rcw600]

I have looked for an answer to this question on the forum and not found one that applies to my particular case, but apologise in advance if it's there and I missed it! I am replacing a freestanding electric cooker with a separate built-in oven and hob. The existing cooker is rated at about 11 kW (max load) and is on a radial circuit wired to the consumer unit with 6mm cable, with a double pole switch on the wall and a 32A breaker at the consumer unit. A pretty standard arrangement I think. The hob I want to install is rated at 7.2 kW and the oven at 3.65 kW. Basically I want to know if I can connect both to the existing cooker outlet or if a new circuit is needed. I've spoken to two electricians, both of whom were quite vague. One suggested conecting the oven to a 13A fused spur on the same circuit, even though the oven is rated at more than 3 kW. The instructions with the oven (Siemens) do not say what rating of fuse or breaker should be used. I even called Siemens, but they just said I should speak to an electrician! Both appliances come with their own cable, with explicit instructions not to replace these with any other cable. My concern if I connect both to the same outlet is that the oven would be protected by a 32A breaker and its cable (which looks pretty much like standard 13A flex, maybe a little thicker) may need a lower rated fuse. I want to avoid a new circuit from the board if possible, otherwise I'll probably have to re-tile the kitchen (not to mention the cost), but if I have to then so be it. If anyone can provide a definitive answer to this question I'd be very grateful. Thanks.

 

[ban-all-sheds]

It really is about time "they" did something about the way that appliance manufacturers sell things in this country which were designed with continental 16A circuits in mind with inadequate instructions or even refusals to provide adequate instructions. I'm pretty sure that not providing instructions is an offence.

http://www.google.co.uk/search?hl=e...&q="consumer+law"+"installation+instructions"

Basically I want to know if I can connect both to the existing cooker outlet or if a new circuit is needed.

If your existing circuit doesn't trip with your 11kW cooker then it'll be OK for the new appliances. You might find it easier to connect them if you replace the outlet plate with a twin one.

But you're right that there are questions to answer regarding the oven.

One suggested conecting the oven to a 13A fused spur on the same circuit, even though the oven is rated at more than 3 kW.

Don't let him back into your house.

The instructions with the oven (Siemens) do not say what rating of fuse or breaker should be used. I even called Siemens, but they just said I should speak to an electrician!

Write to them, or maybe the retailer, (it's harder for people to ignore letters, and any reply will be undeniable) and say you have spoken to your electrician who says that as he is bound by Wiring Regulation 134.1.1 you require full installation instructions and confirmation that the hob can be connected to a 32A circuit.

...its cable (which looks pretty much like standard 13A flex, maybe a little thicker) may need a lower rated fuse.

Is there anything written on the cable which identifies the size?

I want to avoid a new circuit from the board if possible, otherwise I'll probably have to re-tile the kitchen (not to mention the cost), but if I have to then so be it.

Is there any way you could add small enclosure with a 16A breaker in the kitchen, supplied by the cooker circuit?

 

[rcw600]

Thanks for the advice. On closer inspection of the oven cable, the connector that plugs into the oven (it's like a kettle lead) states 16A on it, so I suppose that answers the question. Re your suggestion about a 16A breaker on the same circuit, the only place that could go without the tiling issue would be in the cupboard adjacent to the oven, and it would probably have to be fixed to the inside of the cabinet rather than to the wall (unless the cabinet were removed - another complete PITA). Is that allowable? Thanks again!

 

[ban-all-sheds]

It's not ideal, but not disallowed, particularly if you have it downstream of the cooker switch so that it isnt the point of isolation for the oven.

You'd only need a
small enclosure, e.g.

 

[rcw600]

That's really helpful, thanks. That seems to be the answer and shouldn't be too expensive! Cheers.