Many thanks Badger, sorry for pinching your thread Billy
Do you have a reference (which doesn’t involve buying a copy of NF-1500 
) in case I need to quote it at them?
Edit: I was wondering why -6% stuck in my head, but I think that was part of the UK “compromise” - 230 - 6% is the same (roughly) as 240 -10%
Interesting.
My puissance souscrite is supposed to be 12kVA though.
During a normal day, we use about 3.5kw, when hot water is on about 8 inc normal days requirements so we could go back down to 9kw.
In which case the incoming conductors should be correctly sized, but I’ve come across cases where they were not.
Umm…do you mean kWh, as in power consumed? …or are you talking about peak load, as in maximum demand? Your post is unclear to me.
Sorry I meant consumption, I am going to measure peak load next week as we have been doing all we can to lower it. Hopefully solar thermal will take away the largest loads.