Oven Hob and Extractor Wiring

[Matt789]

Hi all I know there are a lot of questions already regarding this kind of install but most differ in some way

Quick specs:

single oven 2.8-3kw
ceramic hob 6kw
standard 3a extractor hood

Grade of cable - 6mm2
Distance 15 m max
40A MCB at CU

My questions are exactly how i can do the wiring from the oven FCU (which i hope to have in a wall cabinet, should this be a 45A FCU or a 32? screwfix only seem to do 20A or 45A ) to feed the oven hob and hood using additional FCUs that's the neatest 'best practice' way of doing it

What i would like is to have all the fused spurs under the worktop behind cabinets as they shouldn't need to be very accessible

Oh as a final consideration the oven comes with a 13A plug on it so it could be fed from a socket but it can also be hard wired, is there an advantage to either way? I would probably sooner do a socket for it

Thanks in advance to anyone willing to help!

 

[Steve]

Your terminology is all over the place.

FCU/fused spur = 13 amps. This is the ONLY switch that has a fuse in it. And it can be 1, 2, 3, 5, 7, 10 or 13 amps. It is supplied by any circuit rating (within reason)

20 amp switch = guess. Should be used on a 16 or 20 amp circuit. Can be used on other cirucits in certain circumstances.

32, 40, 45, 50A switch = guess.

What I'd do is have a 40A switch ABOVE THE WORKTOP, supplying a socket below the worktop for the oven, and a cable outlet for the hob. No fusing down nessecary.

 

[Matt789]

Thanks Steve yeah i realise some is a bit out

So i can understand it fully i just need to step through some aspects

I'm wring a 40A (still not sure where these can be bought!) switch which can be in a cabinet above the worktop as long as its within 2m of the cooker, then from there running 6mm flex down to where i want my socket sited, and the cable outlet (which i'm guessing is what i have from my existing control unit setup) is again run from the switch? in 6mm

where can the extractor FCU be? thanks for your help

 

[Steve]

Mount the switch and the FCU above the worktop, and BELOW the wall units.

The thing is, if you mount it in a cupboard, the cupboard will gather your junk and the switch will disappear.

IMO a line of sockets, switches etc looks very neat in a kitchen. Dont forget you can get brass, chrome etc.

You can get square 45A (slight correction there) switches.

Dont forget to run cables in safe zones.

And this work is notifiable to building control. //www.diynot.com/wiki/electrics:part p

 

[Matt789]

Sorry i don't think i made myself as clear as i could have, its not so much where i'm physically putting the FCU but how i'm wiring to it

Am i running 3 lots of 6mm from the switch, one to the socket, one to the cable outlet and one to the FCU? only i may be wrong but i don't think i'd ever get them all in the switch connectors

 

[Steve]

Sorry i don't think i made myself as clear as i could have, its not so much where i'm physically putting the FCU but how i'm wiring to it

Am i running 3 lots of 6mm from the switch, one to the socket, one to the cable outlet and one to the FCU? only i may be wrong but i don't think i'd ever get them all in the switch connectors

You should wire the FCU to the ring main as a spur.

As for the socket and outlet, wire them in a row, not both from the switch.

So the 6mm cable goes from the switch load terminals to the outlet, to the socket.

 

[Matt789]

ah now, this is where it gets juicy
As all the sockets around the area have already been spur'd, this may be where you'd probably quite rightly suggest extending the ring main but reading more about it seems you need to use junction boxes ( http://www.diydoctor.org.uk/projects/Extendingringmain.htm ) which to comply would probably have to be accessible, which would look pretty nasty no?

Could i not do what you suggested here?
//www.diynot.com/forums/viewtopic.php?t=40330

 

[Steve]

ah now, this is where it gets juicy
As all the sockets around the area have already been spur'd, this may be where you'd probably quite rightly suggest extending the ring main but reading more about it seems you need to use junction boxes ( http://www.diydoctor.org.uk/projects/Extendingringmain.htm ) which to comply would probably have to be accessible, which would look pretty nasty no?

Could i not do what you suggested here?
//www.diynot.com/forums/viewtopic.php?t=40330[/QUOTE]
Right, hang on. Forget what I might have said 4 years ago. If you want to you can make the hood part of the cooker circuit.

The best way is to supply an FCU from the SUPPLY terminals of the switch (ie. preswitch). This is because it may not be clear that the cooker isolator also switches off the hood. Put the FCU right next to the cooker switch.

It concerns me slightly that the kitchen ring main has loads of spurs on it - and completing the ring doesnt have to use junction boxes if you get the right lengths of cable.

 

[Matt789]

You should wire the FCU to the ring main as a spur.

errm

 

[Steve]

You should wire the FCU to the ring main as a spur.

errm

Re-read what I've written, I edited it, you might have seen the pre-edit version. I hadnt remembered the entire script of what I said yesterday before I wrote it, I apologise.

 

[Matt789]

No need long as we get there in the end i'm okay with it!

So all switches come with "load" and "supply" terminals, and because the FCU is pre switch that'll have to be 6mm, will the socket have to be as well, the manufactures state 4mm for the hob but i only have 2.5 and 6, 6 should be okay in theory shouldn't it?

Thanks for your help maybe some of you should get paypal accounts so people can chuck you a few £'s for good info..

 

[Steve]

So all switches come with "load" and "supply" terminals, and because the FCU is pre switch that'll have to be 6mm, will the socket have to be as well, the manufactures state 4mm for the hob but i only have 2.5 and 6, 6 should be okay in theory shouldn't it?

I think in theory as long as the sums work out, you could use 2.5 to supply your FCU, because its total possible draw is only 13 amps. Im not keen though, and wait for someone more qualified to confirm this.

6mm will be ok to supply the hob. Though the terminals may be designed for 4mm. Try it.

Thanks for your help maybe some of you should get paypal accounts so people can chuck you a few £'s for good info..

Now theres an idea. . . . We do this for the satisfaction. If anyone wants donations its admin. We like to think we've saved people from a few fires, shocks, deaths over the years

 

[Matt789]

Yeah i don't see anything wrong with it - if you've saved people money why not

Now would anyone say hooking the new length of 6mm into my consumer unit bears thinking about or is that a step too far..

I have a book that shows you how but i'll be getting the work certified by a pro anyway so maybe that can be a job i'll pay the extra for if it could mean certain death

 

[wingcoax]

I have a book that shows you how but i'll be getting the work certified by a pro anyway so maybe that can be a job i'll pay the extra for if it could mean certain death [/quote]

You should get the pro to do the work.He should only certify the work he has done personally.

 

[spark1]

Matt
This work falls within the rules of the Building Regs. Part P. to be precise, as previously stated. The job is a commonly encountered one with a very straightforward solution.....if you are giving prior notification to your local Building Control then I can advise you of the correct way to wire the circuit...if you are not notifying it then I cant........Which one is it ?