New Cooker installation

Mitchet · Posted: Thu Jul 12, 2007 3:08 pm Post Subject: New Cooker installation

Hi, I wonder if anyone can help clarify somethine for me please?

Friends of mine are currently having their kitchen refitted. Since I've done a fair bit of electrical work in my time (though not so much these days!), they asked me about moving the main cooker switch (its current position would leave the switch over the hob unit, which is a no, no).
I've no problem with moving the switch, even though it's going to have be relocated in a cupboard to the right of the cooker (because the cable won't reach to the desired location).
But yesterday when I went round to do the job, I noticed the existing cooker circuit is only 30A (fused). My concern is that they've opted for a new electric range cooker which has a double oven/grill and 5 hobs. The maximum rating stated for the cooker is 14.6KW (63.5A ?), and although I know this is a maximum rating, and leaving out the discussion on whether load diveristy applies or not

, I just don't think the circuit will be suitable for their new cooker.

The cable run from the CU would be approx 8-10M, with 6mm cable used.

My suggestion would be to have an additional 30A circuit installed for the oven units, and use the existing 30A circuit for the hob unit. This would ensure enough capacity for the cooker to be used to full capacity (as the grill cannot be used at the same time as the main oven).

Their problem, is that
(1) it's an old CU, with a maximum rating of 60A
(2) The CU is at maximum capacity...
(3) ...therefore the cost is going to be fairly high to have a seperate CU installed and a new circuit to the cooker point.

I'm just really after your opinions on whether I'm on the right track, or if you have any suggestions?

Incidentally, they have had an electrician tell them the 30A circuit would be okay to use... ???!

Thanks for your help in advance.

Taylortwocities · Posted: Thu Jul 12, 2007 10:27 pm Post Subject:

There's lots of similar posts to this. Sure you can connect up using the existing 6mm cable/30A set up and it will work fine until something like Xmas day arrives. All the hob rings are on and the turkey is in the oven - thats when the fuse wire will pop.

If you ran another 6mm feed, how would you connect it? Is the hob supply separate to the oven?

You've still got the connectivity issue at the board. Maybe better to run a new 10mm cable and install a mini board for that circuit.

What sort of board is the xisting one? Can u post a piccy? Note that your existing board may have a current limit of 60A on it (it should say this) and the max for any individual fuse will be 30A.

Re moving isolation switch? Dont forget the cable must run horizontally or vertically to the switch which must be within 2 metres of the cooker, you cant pull it diagonally or in a dog-leg config.

Last PS, do remember that any new circuits and work done in a kitchen is notifiable

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securespark · Posted: Thu Jul 12, 2007 10:32 pm Post Subject:

as long as your cooker switch has no socket on it, & you apply diversity, a 30A circuit is fine.

Just make sure the switch is accessible & 2m or less from the equipment it feeds.

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Mitchet · Posted: Fri Jul 13, 2007 11:36 am Post Subject:

Taylortwocities wrote:

Re moving isolation switch? Dont forget the cable must run horizontally or vertically to the switch which must be within 2 metres of the cooker, you cant pull it diagonally or in a dog-leg config.

The switch is within 2 metres, but regarding the dog-leg comment.. is this a reg or is it just best practice?

The existing cabling for the cooker ran diagonally from the isolation switch?!

Chivers7 · Posted: Fri Jul 13, 2007 1:41 pm Post Subject:

If you run it as a "dog leg" then it is unlikely to be in a safe zone and if it's not it will not comply with regs.

Taylortwocities · Posted: Fri Jul 13, 2007 4:42 pm Post Subject:

You can only run a dog leg if there is an accessory (eg switch etc) directly above the bend and another accessory siruated horizontal to the location of the bend.

Otherwise the cable is not run in a 'safe' zone.

Here's why you must comply http://news.bbc.co.uk/1/hi/uk_politics/3735928.stm

__________________
TTC

When you get to the end of your rope, tie a knot and hang on. - F.D.R.