Con Fused

[Dai]

Now I am confused after reading the many articles on cooker/hob diversity/non diversity topics I need help !!!!!!!!.
I intend to replace my existing free standing cooker with oven and hob option (oven 4kw hob 6.4kw) the existing circuit is in 6mm wiring, protected by a 32mcb at the fusebox. The cooker control unit is on the wall above the outlet (approx 0.5m below) with the cooker control unit allowing for a little extra in routing through floor joists above is 6m back to fuse box. There is no socket on the control unit.

1/ Applying diversity the circuit seems correct . do i apply diversity or not.

2/ If not what do you recomend

3/ If i change cooker control unit to one that has a socket to run a
cooker hood (3amp) what affect will this have to the whole set up.

I now this next statement will seem a little annoying but could i get a definitive answer to cable size, mcb size and definitely to apply diversity or not.

P.S. I am new to this site and would like to thank all of you that have replied to all my previous posts.

 

[JohnD]

I will only say one thing:

Don't change to a CCU with a plug socket. The circuit loading is already rather high. A plug socket on a CCU is not a good idea, as someone will (1) plug in a 2kw kettle which you can't spare the power for, and (2) drape the flex over the hob where it gets burned and (3) you won't have an RCD on the cooker circuit, so when someone pokes a knife down the toaster or drops the kettle in the sink they will be at more risk than is necessary.

I'm glad I've got a Gas Hob.

(no, I'll say two things:
As you have a BIG oven and a BIG hob, why not splash out on two circuits? Then you can have MCBs that more closely match the max power draw of each appliance.

(no - three things (!))
Your cooker hood is a fixed appliance, so put it on an FCU from the socket circuit. Have you got plenty of sockets?

 

[Dai]

OK if i add another feed to the oven (6mms) leaving the original for the hob (or other way round) Which i can do because there is space to add another mcb at the fuse box.

1/ is it recommended to move the original ccu from above the hob and if so can i then use one with a socket

2/ obviously the second feed would also need a cooker control unit what amp mcb would you recomend (32mcb again)

3/ difficult to get a spur off existing circuit to hood (with fcu) stupid question can it be taken off lighting circuit with fcu fused with 3amp

Thanks for your reply, John D

 

[JohnD]

1) CCU should not be directly above the hob, but to one side (within 2m) so that you do not, for example, have to lean over a flaming chip pan to turn it off

2) Cable should be sized to accomodate the maximum load that can be placed on it (so total load of appliance, ignore diversity here, even though the books say you can apply it to avoid spoiling your Christmas dinner). I would be inclined to have any new cooker circuit in 10mm in case you decide to get a vast range cooker next time.

3) MCB sized as close as you can get to the max load of the actual appliance (there is a bit of design judgment here - for a cooker I would rather the MCB be a few amps under max than a few over - and you will probably have a choice of 16, 20, 32 or 45).

A fan on a lighting circuit is already (presumably) fused at 6A so doesn't need an FCU unless you feel like it. It should have a DP switch though.

Don't forget building Regulations for new circuits and kitchen work. You could include the extra sockets and FCUs you seem to need in the same application.

 

[securespark]

1) CCU should not be directly above the hob, but to one side (within 2m) so that you do not, for example, have to lean over a flaming chip pan to turn it off

Or even a bloody frying pan...

 

[JohnD]