New Kitchen - Fitting Electric Oven

[jjrideon]

Hi,

I'm renovating an old flat, putting in a new kitchen at the moment. The old gas cooker has been removed and I wanted to put in an integrated electric oven and gas hob.

The first worry was that there wasn't a seperate ring for the cooker (the old one was gas) that we could connect the oven to. After checking out these forums, I saw that as the oven is rated at 2.4kw, a 13amp fuse would be OK and it could go onto the kitchen plug ring.

But now it looks as if all the sockets in the flat run on just one ring. Is this going to be too much load if we put the oven on that as well? It's a 2 bed flat with about 15 double sockets. No electric shower, but there will be a washer dryer, maybe a microwave, obviously the fridge and kettles etc.

Is it safer to run a ring just for the oven back to the consumer unit? It's going to be a nightmare to do as they are at opposite ends of the flat! Can this run outside along the wall if its placed in appropriate trunking? That would be easier to run rather than through ceiling or under floorboards...

Many thanks for any help in advance!

Jay

 

[slippyr4]

Firstly, a cooker circuit is never a ring, it's a radial. Ring finals are used for socket circuits.

You can have as many sockets as you like on a ring final, provided that the floor area covered doesn't exceed 50 square metres.

However, it might not be a great idea to run everything off one ring, you'd need to consider the load from other appliances, as you've started too.

A fridge takes very little power. Things that matter are basically things that get hot - so heaters, microwaves, washing machines, tumble dryers etc.

Consider how many of those you're likely to use at once, and add up their required currents. If this exceeds the capacity of the breaker on the circuit in question, then you might have problems.

You also need to consider that the duty cycle of these appliances is rarely 1. Your washing machine will only pull loads of power when it's heating it's water, you oven would cycle on and off according to the thermostat.

Only you can decide which is more hassle - running a new radial for the cooker, or having a fuse or mcb blow on overload.

Personally I'd run a new bit of 6mm^2 T+E from the CU to the cooker, and run it under the floorboards, even though it's a hassle. That would give you some futureproofing.

Your oven technically only needs 2.5mm^2 T+E on a 16 or 20A fuse or breaker, but I would still use 6mm^2 for the future proof aspect.

 

[JohnD]

Agree.

If you're "renovating an old flat, putting in a new kitchen " then this is the time to put in a circuit for an electric cooker. People expect it. In a small kitchen there may only be room for a single electric cooker or oven, so a 32A 6mm circuit would do. If it is a large kitchen people may expect to have both an electric hob and a double oven, so you would need two. If it is a huge kitchen a future owner may wish yo install one of those riduculous enormous range cookers with three ovens and five or six rings, so a 10mm 45A circuit would be appropriate.

If you are taking up floors and chasing walls then it is not much more work to put in two circuits than to put in one. The materials cost will be somewhat higher but not a great deal of money.

BTW buyers are very inflexible on the sort of cookers they want. Women whose mothers cooked on gas want a gas gooker. Women whose mothers cooked on electricity want an electric one. Expert cooks insist on a gas hob and an electric fan oven. Few of these people will accept anything else.

 

[slippyr4]

Women whose mothers cooked on gas want a gas gooker. Women whose mothers cooked on electricity want an electric one.

Sexist John!

 

[jjrideon]

wow- that was quick!

thanks for your advice. I should explain a little bit more...I'm renovating the flat as a temporary measure. I'm putting in a planning application to add an extension and convert it into 2 flats at the moment (it's a very oddly laid out 2 bed at the moment), but it really needed some work doing to it now so that I can rent it out for the next 6 months /year while planners do what planners do...

the kitchens for both future 1 bed flats are very unlikely to end up where the current kitchen is, hence not wanting to spend too much now when it's all gonna get ripped out and completely re-wired and plumbed (hopefully) in a year. fingers crossed I can re-use some of the kitchen units, oven etc.

i think i'll run the new cable from the consumer unit to the oven now as the hassle of getting called up by tenants every few days about the power tripping out isn't worth the cost saving! is it possible to run it outside in trunking? this flat has had so little done on it for 30 years, that i'm terrified of trying to lift up floor boards only to uncover a new set of problems!

thanks again,
jay

 

[jjrideon]

So an electrician came and looked at the job and said that I would need a new consumer unit (It is the old style fuse box with the large 'pull out' fuses with replaceable wire.)

Sorry I just realised that 'consumer units' is the term just for new boxes and I incorrectly used that in my earlier post...my apologies, as you can tell I'm no electrician!

Anyway - he said that he wouldn't connect anything to the old fuse box as the oven radial needs a RCD?? (I think those are the letters he used but I could be wrong) Is that right? Is there anything else that can be done without replacing the unit, bearing in mind that in 6 months I'm gonna split the flat into 2 flats and have it all rewired for that?

Please help me as I'm rapidly getting out of my depth and am getting conflicting advice from the electricians I am speaking to (I don't have one I have used before!)

Thanks again,
Jay

 

[slippyr4]

Anyway - he said that he wouldn't connect anything to the old fuse box as the oven radial needs a RCD??

That's not the case. If you used a cooker connection unit with built in socket, and it's a ground floor flat, then maybe. But otherwise no.

It's hard for us to judge what it and isn't possible since we can't see the flat. Get more quotes from other electricians, go with what you're happiest with. Not necessarily the cheapest though,

 

[JohnD]

It is in fact better not to have an RCD on a cooker circuit. It is also preferable not to have a socket on it; that only encourages users to plug the kettle in there and drape the flex over the hob.

 

[securespark]

You can have as many sockets as you like on a ring final, provided that the floor area covered doesn't exceed 50 square metres.

100!!

 

[JohnD]

Any advance?

Going once at 100, going twice at 100...

 

[securespark]

Ooops!

Have you already "hundreded"?

 

[jjrideon]

thanks everyone...

i'll try and get someone else in to have a look as well...pretty hard at this time of year...

so someone should (in theory) be able to run the correct cable (6mm^2 T+E) from the a spare point on the existing fuse box (even though it's old) with the correct amp fuse (16amp- is that right for a 2.4kw oven?) directly to the oven? no need for anything else- would you put in a breaker?

out of interest, why does being on a ground floor flat make a difference? (it is)

 

[slippyr4]

so someone should (in theory) be able to run the correct cable (6mm^2 T+E) from the a spare point on the existing fuse box

Only if there's room, which there may not be.

out of interest, why does being on a ground floor flat make a difference? (it is)

Sockets which are reasonably expected to be used to supply equipment outside must be RCD protected. This "reasonably expected", although not defined properly anywhere, is usually taken to mean any socket on the ground floor.

 

[DESL]

I had quite a lengthy debate with an assessor on this subject.

He insisted that cooker should be on RCD and I argued against it as the property had o/s sockets, the cooker socket was the furthest from the kitchen door. The door led into a conservatory which had 3 double sockets on an RCD.

I eventually won the day by putting a sticker on cooker socket saying not for outdoor use.

I did argue the case using the reasonably expected phrase from the regs but was told I have adhere to part poo provider rules.

I didn't want to move cooker feed in CU as I'd done a really neat job of it.

I don't fit cooker outlet with sockets now!!

 

[securespark]

I had quite a lengthy debate with an assessor on this subject.

He insisted that cooker should be on RCD and I argued against it as the property had o/s sockets, the cooker socket was the furthest from the kitchen door. The door led into a conservatory which had 3 double sockets on an RCD.

I eventually won the day by putting a sticker on cooker socket saying not for outdoor use.

I did argue the case using the reasonably expected phrase from the regs but was told I have adhere to part poo provider rules.

I didn't want to move cooker feed in CU as I'd done a really neat job of it.

I don't fit cooker outlet with sockets now!!

In theory, you only need RCD protected outlets adjacent to outside doors to comply with 7671, providing all others are marked as unsuitable for supplying equipment outdoors.