Multiple Ovens In A Domestic Kitchen - Diversity

[ProDave]

If you are intent on leaving them all on one 32A radial then how about a mini CU in the kitchen with 4 16A MCB's one for each oven?

And as already warned, come Christmas and the big party and all 4 ovens in use, you will be the one sat in the cupboard keep resetting the 32A MCB.

 

[NozSpark]

I recently had to rewire an electric hob that was wired from a 32A rfc via a 13A fused spur.... I was told that it had blown the fuse on Christmas day!

IMHO... If you're going to do this then do it correctly,, it'll only be a temporary disruption in those 2 other rooms and then you should never have any problems with it again

 

[Doc Hudson]

Hi all.

i recently asked this on a screwfix forum, but unfortunately only got one response. With due gratitude to that person I wondered if there were any other opinions?

I am considering the electrical and builders work implications of a domestic kitchen refurb which is presently in the planning. I have limited space for expansion in the consumer unit so need to keep this in mind. The kitchen will have a ring main for countertop sockets. Additionally I anticipate a 32A 6mm2 T&E radial to the 7.5kW induction hob.

Under the countertop is arranged two single multifunction ovens (3kW + 3.5kW) and two compact multifunction ovens (combi steam and combi micro (3kW + 3kW). The manufacturers info states minimum 16A fuse connection on each appliance. The ovens are arranged horizontally side by side in a group. With diversity in mind is there are reason why the four ovens should not share a single 32A 6mm2 radial with single above counter DP switch continuing with a drop to four individual connection units behind the four appliances? Thanks in anticipation

With such design questions the space in or around the consumer unit is academic. If more circuits are needed then they are needed. Or if there is absolutely no room anywhere within the installation to wire a sub main to addition distribution board then you simply don't add any more circuits. As you can only extend an installation that is capable of being extended. That is one of the fundamental principles of design detailed in chapter 13 under alterations and additions.

With regard to keeping diversity in mind, unless you provide some more specific details it is quite hard for anyone not familiar with the particular installation to consider if diversity can be applied or not. There is no one size fits all table for calculating diversity. BS7671 clearly states that specialist knowledge and experience of the particular circuits under consideration is required. Such as the maximum load a circuit may draw, duration that individual loads may be in use for, how many other loads will be in simultaneous use. etc. Appendix B of the on site guide gives guidance. as does guidance note 1.

Doc H.