Hob/Oven Circuit issue

[adsmith]

Hi all

Some advice on this would be great.
Due to wire a kitchen from scratch and in a pickle over the designing of the oven and hob circuits due to having to carry out first fix before appliances are agreed on due to time restraints.

My original thought was to run a 6mm cable on a 32amp breaker to the cooker isolator and then to a dual connection plate to both the hob and oven.
issue I have is I'm yet to know what exact appliances are being purchased so don't know what kW rating both will be and also whether the oven will be hard wired or on a 3 pin plug.

so I guess my question to you guys is am I best going ahead with the 6mm cable like mentioned or separate 6mm cable for hob circuit and 4mm radial for an oven circuit (which could be connected to a single socket if oven on 3 pin plug) but obviously this will mean another breaker will be required. which could also be a problem.

note if I was to go ahead with the 6mm radial and the oven comes with a 3 pin plug what would I do as the cable would end at a connection plate

regards

Andy

 

[Dustydazzler]

More often than not , when wiring a kitchen blinds as in I don't have the exact appliance spec then I take 2 x 4mm cables from the board to the oven/hob location. this gives you some flexibility to have 2 32amp feeds and also I just prefer using 4mm than 6

 

[Vortigern]

First, what is the installation method? More and more nowadays hobs are up to 7kw due to induction and ceramic. Oven can be 2.3kw to 3+Kw. Presumably there is a plan for the kitchen you are working off? Installation method is important as it will affect the size of cable i.e. insulation, clipped direct etc. You could assume worst case scenario and put two 6mm² and wait for the appliances then fit the accessories, i..e. Dual outlet, cooker outlet or something else. Most appliances I fit nowadays have a label on the cable saying " DO NOT FIT PLUG TO THIS CABLE" I think you really need to know the loading or you cannot properly design. Usually diversity factors take the Kwage right down anyway.

 

[Mike Johnson]

As above, I would just fit two 6mm radials, can't be wrong that way.

 

[happysteve]

If the oven ends up being on a plug (or <= 13A and needing an SFCU) then you could install a 1G socket or SFCU using one of the outlets of the dual connection plate.

 

[adsmith]

Thanks for the reply Guys.
Now found they are going for a all electric hob/oven range cooker at 13.2kW. With diversity (no socket) =23.5amp so I know I'm good with 4mm radial on existing 32amp breaker but seeing as new install I think I'll fit a 6mm cable for future proof etc.
Interested to see your opinions on cable size. Would you yourself in this situation fit the 4mm on 32amp breaker or beef up?

 

[happysteve]

Personally I'd always fit 6mm. There was a thread on here a month or two ago where an electrician had run 4mm on a 32A breaker, another electrician had sucked their teeth about this and refused to connect it up, and the original poster (the home owner) didn't know who was correct and posted here for advice. There was a fair amount of debate; interestingly, the original electrician actually posted to the thread after a lot of to-ing and fro-ing to justify their decision (citing reference/install methods, voltage drop etc).

So it's one of those cases where 4mm may be fine on paper and comply fully with the Regs and associated guidance (assuming CCC, VD and Zs are all good), but it's not what people expect... so to save yourself and the client uncertainty in the future, just put 6mm in.