Converting to a 16A cooker switch?

[bobthedob]

So John, you didn't add the "5A for the cooker outlet" - rightly because I don't have one!

But could I disconnect one of the pair of 2.5mm2, add a 20A DP switch at the island end, and use the diversity calc to say its fine? Or add in the 5A and then I am in trouble again.

Strictly speaking its a 13A spur right?

 

[Taylortwocities]

Youll need a 13A fuse to limit the current from the ring final. Either an FCU or 13A plug. There’s no ‘strictly speaking’ about it.
The best route would be to use one of those underfloor tails as a new 16A radial from the consumer unit. But you’ll need a registered spark to sort that out for you.

Question. Why is the kitchen ring only protected by a 16amp MCB? It should be 32A for a ring final.

 

[bobthedob]

Youll need a 13A fuse to limit the current from the ring final. Either an FCU or 13A plug. There’s no ‘strictly speaking’ about it.
The best route would be to use one of those underfloor tails as a new 16A radial from the consumer unit. But you’ll need a registered spark to sort that out for you.

Question. Why is the kitchen ring only protected by a 16amp MCB? It should be 32A for a ring final.

The kitchen ring does have 32A MCB - that was part of my discovery process!! I was looking at the wrong circuit.

I agree on the correct path is a new 16A radial. But if I ensure I have a 13A fuse on the spur it would protect the ring main.

Thanks for all your help guys. You have been great.

 

[ban-all-sheds]

Its actually on the damned kitchen ring circuit.
Somewhere the pair must come out at a double socket on the ring main

Not necessarily.

 

[JohnW2]

So John, you didn't add the "5A for the cooker outlet" - rightly because I don't have one!

I don't really understand. Are you perhaps talking about the 5A one has to allow if there is a socket as well as a cooker (as with many 'cooker control units' - which is not relevant to what you were talking about?

But could I disconnect one of the pair of 2.5mm2, add a 20A DP switch at the island end, and use the diversity calc to say its fine? Or add in the 5A and then I am in trouble again.

I thought you/we had established that it is a ring circuit? If so, and if I understand you correctly, if you 'disconnect' one of the cables, you would have destroyed the ring, which would then be non-compliant with regulations (and potentially at risk of overloading cables).

Strictly speaking its a 13A spur right?

Provided the other loads being applied to the ring left enough capacity, the oven could be installed as a spur from the ring circuit, but that would involve adding an additional (third) cable to one of the sockets on the ring, not 'disconnecting' anything.

Kind Regards, John

 

[bobthedob]

Are you perhaps talking about the 5A one has to allow if there is a socket as well as a cooker (as with many 'cooker control units' - which is not relevant to what you were talking about?

Yes that is where I got confused. Apologies. Forget the 5A.

I thought you/we had established that it is a ring circuit? If so, and if I understand you correctly, if you 'disconnect' one of the cables, you would have destroyed the ring, which would then be non-compliant with regulations (and potentially at risk of overloading cables).

Again you are spot on and I hadn't really thought that through had I!
Of course that would break the ring. I could get around that by adding a link between the two sockets which are next to each other, but why bother.

I think I am better off leaving the ring go out into the island, as it is now, and then putting my new fused spur off the socket out in the island.

Not forgetting that the correct solution is a new radial 16A circuit from the fuse box.
So glad you are paying attention.

 

[JohnW2]

Again you are spot on and I hadn't really thought that through had I! Of course that would break the ring. I could get around that by adding a link between the two sockets which are next to each other, but why bother. I think I am better off leaving the ring go out into the island, as it is now, and then putting my new fused spur off the socket out in the island.

Indeed. As I said, if you want to run the oven through a plug/socket, using the ring circuit, that oven socket could just be a spur from a socket on the ring (i.e. a third cable from one of the sockets on the ring). It needn''t be a fused spur, since there would only be one socket, and the associated plug would have a 13A fuse.

Not forgetting that the correct solution is a new radial 16A circuit from the fuse box.

There's a lot to be said for a separate dedicated circuit for an oven - but, as has been said, your oven would need less than 13A.

Kind Regards, John

 

[ban-all-sheds]

I think I am better off leaving the ring go out into the island, as it is now, and then putting my new fused spur off the socket out in the island.

I'm confused.

You have a socket in the island - why do you want to add another as a spur?

 

[JohnW2]

I suspect the existing socket is actually used/needed - hence a need for something else to feed the oven.

 

[ban-all-sheds]

I don't.

Can I replace the 13A socket with a 16A cooker switch?

 

[bobthedob]

I don't.

A good night's sleep has helped me realise that I have gone around in one huge circle here (especially once I realised how the island was actually wired in!)

I could re-title this whole thread as "can I put a 13A plug on my new cooker?"
With the huge caveat of it being better to put a new radial in, then the answer is yes I can.
I can put a 13A plug on my new cooker, take out the old cooker (with existing 13A plug) and just swap.
The diversity concept was new to me, and that makes me more comfortable.

So 'ban-all-sheds' you are right; I will just add a plug and use existing island socket, and put in a new radial when I next have a sparky around.

Thanks again for everyone's contribution.
Its great to hit a forum where there is fast help, and none of the negative comments one often seems to get these days.

 

[securespark]

The cooker needs replacing and everything is 16A these days, even for a 3kW oven

Have the manufacturers changed Ohm's Law?

 

[ban-all-sheds]

Ah, the perilous combination of arriving late to a topic and not reading all the posts in it before replying....

 

[bobthedob]

Have the manufacturers changed Ohm's Law?

No but I think the EU has

 

[JohnW2]

Have the manufacturers changed Ohm's Law?

I wouldn't put it past them

I wonder what the exact wording is. Are they perhaps saying that it needs to be fed from an ('at least') '16A supply' - which would usually be the case, since the next readily available MCB is 10A (and, of course, since it would essentially be 'the norm' in most of Europe)?

Kind Regards, John