Power Supply for Induction Range

[hedgehoglurker]

We are hoping to replace our dual fuel range with an induction range. According to the paperwork from previous owners, a new supply for the cooker was installed in 2008 - along with a new consumer unit and some other works.

The switch on the wall is not red, but has a red light. Is there a way to tell from the installation certificate that it will be suitable for the new range? Or do I need an electrician to visit to confirm?

The range requires a 32amp fuse rating, and the breaker in the consumer unit is B32, so this seems correct.

We intend to pay the company supplying the cooker for a removal of old and installation of new service, but all they ask online is if it is a "red switch" - which it isn't - it is chrome with a red indicator light.

Photos hopefully attached

looking at your switch, I can't tell if it is a 30A or a 20A.

the 30A switches are usually bigger. The wires in the wall are very thick and stiff and it is difficult to contain them neatly in the small backbox. However there are some that size, and even 45A switches.

An electrician could take it off the wall and have a look

As the wall is tiled it would be fairly tedious and dusty to cut out the wall and fit a bigger one. Send a photo to your cooker supplier (but I suspect they will say the same)

If you can identify the brand of your switch you could look at their catalogue to see if it can be identified by appearance.

There are some examples on here

p.s.

if you take it off yourself, you may find it terribly difficult to get back on, if the box is cramped with thick wires, or if they have been cut very short.

In a drywall, with a space behind the plasterboard, it should not be so hard.

@PigletJohn Thanks so much for responding. We'll have to look at our options, as it doesn't look promising.

A couple of extra photos, just in case!

I can see a big brown and a big blue, but I can also see a smaller red and G&Y. There is presumably also a smaller black.

that suggests to me that you may have at least one undersized cable.

the red and black will be the old ones, and the brown and blue relatively modern. The colour standard changed 2004-2006

I think you'd better get it professionally looked at to see what is going on.

@PigletJohn The red cable IS actually thick, just like the blue and brown (just further away, so looked thin in the photo). It is just the green/yellow that are thin. (Can't see a black cable.) It is very tight, as you said, so difficult to pull away for a clear photo.

I intend to replace the kitchen including knocking through to the dining room, but with the current sky-high prices have decided to hold off for a year or two and make interim changes like a new cooker to make the current small kitchen more workable and safer - the current hob on the range doesn't have a safety cut-off for the gas.

So, as the 3 cables are thick, we could hopefully upgrade it to a 32a red switch?

You really do need to get an electrician to look at this arrangement, and at your consumer unit as a whole too. You''ll want an electrician to do the upgrade anyway, surely?

if it has a thick brown, blue, red and black, the cables should be OK. Your installation certificate says 6mm for the cooker circuit which is normal.

The G&Y wires are two sizes smaller, because the earth wire does not normally carry any current (only under fault conditions, which would usually cause the power to trip) so should not carry power for long enough to overheat.

You may need to fit a new 32A DP switch, or your old one may be adequate, I can't tell. The rating will be embossed on the plastic on the back, you might be able to photograph it from behind with a thin camera or a mirror.

There is a faint chance that the black cable from the red-and-black pair has been sleeved or extended or replaced with blue, for some unusual reason. There should definitely be an "in" pair and an "out" pair.

p.s.

you might find you can't tighten the screws when you try to re-fit it.

if so, stop trying and come back.

I hope this is clear, the mirror was brilliant! It says Load 45A. Thick Red and Black at the back with thin g/y.

I guess the best bet is to have an electrician change the switch to a red one, hopefully without hacking out the wall - it is not plasterboard. Or have it delivered but then fitted by a local electrician rather than supplier.

The range I'm looking at is out of stock in most places, but I've found a supplier with 2 available and don't want to miss out.

If it's 45Amp, it is fine for your needs. You don't need to change it unless you dislike the colour or something. Notify the cooker co that the circuit is run in 6mm cable and the DP isolator is rated at 45A and that you have the installation certificate.

You can send them a photo of the switch back and front

and the cables provided you can take a pic that doesn't make them look small.

You should have, in the wall probably behind the cooker, a cooker connection plate, about the same size as the switch (70mm square) but almost certainly white plastic, with a fat cable coming out and going to the cooker.

examples

Occasionally the cable comes straight out of the plaster but that is poor practice.

Wow, thanks for the comprehensive answer. As usual, @PigletJohn to the rescue! I now know what to request, so hopefully all will work out.

Our consumer units should be ok, with one new in 2010 and the other updated too (to 17th Edition iirc). We bought the house last year and immediately converted our garage including installing an electric shower, so our 2 consumer units were worked on, electrician happy with no mention of concerns etc. Electric Certs and Buildings Regs were issued for the garage conversion.