my mate is replacing his electric shower, 7.5 kw for a 9.5 kw as part of a bathroom refit. it is wired with 10mm t &e to a twenty year old ccu with bs 1361 fuses and the shower fuse is 30A. choices? 1) remove the ccu and replace it with a twin RCD one 2)fit a shower enclosure with an RCD and one oe two breakers, most seem to offer a 50A breaker inc. for between �30 -�40. choice 2 brings up the problem of running a supply to the new small add on. the home is a bungalow with 6 existing fuses in the ccu and it is his intention to employ a spark to fit the method he chooses and also get a 10 year check on all of the property at the same time. any advice would be welcome p.s. they are elderly and will not be looking for spare ways for the ccu, for future use
If it was me I would fit a new CCU, because he will probably need his earthing upgrading anyway ie equipotential bonding conductors to the gas and water and Supplementry bonding conductors across the copper pipework, radiator. He's also protected if he's using an electric mower/external lighting etc. Plus the is always the peace of mind knowing you'e had the installation inspected and tested by a professional.