Well if it isn't possible to use boost on all the zones then it isn't possible for it to get up to 15.8kW. If we say 6kW for the ovens then you could have a hob "rated" at up to 13kW and be able to use a 32A circuit. Your 11.1 + 6 load comes to 30A. Can you show us your calculations? And tell us what the installation method of the cable is?
Personally I would install the 10mm if it was a new installation. If there was a 6mm cable already installed thats when I would start looking at installation methods to check if the 6mm is suitable.
It's true that we don't know the installation method. But we do know that absolute worst case makes a 6mm² cable OK for a 12.kW cooker, and method 100 or 102 4mm² OK for a 15.2kW one.
If the cable is installed under certain circumstances it will need to be de rated and before you can choose what size cable to install you need to check all the variables, you have only checked the design current...which is a good start
If there is a circuit already installed then you won't need to design it,you would need to verify that its compliant thats the point I was making
That's true. The point I was making is that if there is no existing circuit you don't just bung in 10mm² without thinking. You are not supposed to do away with cable calcultions, you are supposed to do the opposite. You are supposed to design it.
You are right and when you design it you consider the present and potential future requirements. Because the price difference between 6mm and 10mm is so small it is a better idea to install 10mm. Its better for the homeowner who won't need to upgrade the circuit any time soon and its better for the next installer who comes to connect the new range cooker and finds a nice 10mm cable waiting If you just install 6mm without considering future usage do you think you have designed the circuit correctly?
By installing 10mm and avoiding idiotic debates that just go round and round and its also 1 more benefit you gain from designing the installation appropriately
There you go with your dangerous advice again. Clipped direct only. Somebody will take notice of you one day and try to save a few quid, putting undersized cable in under insulation etc. Stop it! Post sensible advice.
Gents, I think the point here is that the OP asked for advice and he got it. To summarise, there is no issue in fitting a 10mm cable outside of a slightly higher initial outlay and possibly wasting little more than he could of gods creation! The 10 mm cable will serve him and any future occupants for anything new that might come along also. Everyone is happy and no hard feelings......
It's OK - I get it. You think that just whanging in big cables because you don't want to have to bother doing calculations counts as exercising reasonable skill and care. I doubt that there's anything anybody can say to change your mind, so I'm not going to try.
I haven't read this all the way through, just got the jist. Don't bother with 10mm it's quite an effort to install it and also it's likely you will have issues with the terminations. It might be ok in a commercial kitchen but it's way OTT in a domestic. You will never need ~60a draw for a hob.