Fitting Cooker to MCB

[DaviesL]

I have just bought a new cooker (Smeg SUK61MF5) which has a gas hob and electric oven. The cooker is rated at 13A (in fact it came with a

13A 3 pronged plug attached). I wish to fit the cooker to its own circuit on the mains as i don't want any unnecessary leads over my worktops. The current MCB for the cooker circuit is 32A (it has the following written on the MCB - manufacturer:CPN; code: MC132B B32). As the cooker is 13A I would like to change this MCB to 13A. Firstly, does this sound sensible? Secondly, I can't seem to find a supplier of 13A MCBs but have found 10A, 16A and 20A - can you point me to one? Thirdly, would one of these alternative current MCBs work just as well?

Any help greatly appreciated.

Lee

[Owain]

Yes, as the flex for the cooker may not be (probably isn't) rated for 32A

16A would be preferred, 20A would probably be okay.

Owain

[David Hansen]

On 31 May 2007 04:07:49 -0700 someone who may be DaviesL wrote this:-

It is one approach and probably the neatest/easiest, if you are competent to do the work in the consumer unit.

I would be very surprised if you could get one of that rating.

You should fit the 16A one. This should protect the flex adequately.

How are you intending to connect the flex to the fixed wiring?

[John Rumm]

I take it the exiting install already has a suitable cable in place?

What is currently on the end of this cable?

The MCB fitted should offer the required fault protection to the cable. So if you already have all that fitted, then all you need to is fit a socket to the end of it in a suitable location for the cooker, and plug it in. The fuse in the plug will provide adequate protection for the cooker. With cookers it is desirable to have a way of isolating the supply that does not involve having to pull the cooker out. So a socket positioned at the back of an adjacent cupboard can work well here if you want to save fitting an isolating switch above the worktop.

If you want to reduce the MCB size as well you can. A 16A one would be the nearest match. However as long as the present one is appropriate for the cable the circuit is wired in, you could leave it alone.

[DaviesL]

Thanks all.

There's a connector box in the wall which is then wired (in the wall) to the cooker switch (you know the one with the big red switch) above the worktop. I was intending on connecting the cooker to that and just changing the MCB fuse. I don't particularly want to remove the connector box and replace it with a socket.

So my plan of action is change the MCB to a 16A and then wire the cooker up via the connector box in the wall behind the cooker to the big red isolating switch above the worktop. Sound good?

Thanks again. Lee

[John Rumm]

Yup, should be fine.

[Ed Sirett]

The simplest would be to change the cooker flex outlet unit behind the cooker to a single unswitched 13A socket. No change of MCB required.

Or cut off plug and wire into to the cooker flex outlet and change MCB to

16A.

[robgraham]

Umm - and just how long will it be passing 32A before the MCB trips ? Milliseconds !! And it is very unlikely that it will be passing anything other than its normal working current or something well in excess that will trip the MCB whether it is 16A or 32A.

Rob

[Owain]

Umm, a 32A MCB will carry 32A for a lot longer than milliseconds. Years, hopefully.

It may be possible to prove by calculation that the flex is adequately protected by the 32A MCB and the nature of the load. That does not mean that (a) it is not sensible to change the MCB, or (b) the cooker instructions require the cooker to be protected at

[Lurch]

On 31 May 2007 10:46:51 -0700, robgraham mused:

Er, no.