My wife has as many prostheses as normal limbs and can no longer bathe, so she's going to get a bit niffy by the time of our Golden Wedding anniversary. Being of a kindly disposition, I offered to put in a 10.8kW shower.
Realistically, of course, someone who has to use a spoon as a lever to open a ring pull can and has trouble bending to undo a sink trap, is in no position to wrestle with 10mm^2 cable in confined spaces. But, living in a remote rural area where the undertaker doubles as bus driver/mechanic, the stonemason as chiropodist and the barber as umbrella repairer, probably the best I can hope for is someone who 'has done a bit of wiring', so it's important to get my ducks in a row before calling him in.
The house is built of random shale with soft lime mortar (which means that drill bits go where they want to and most conventional methods of fixing are out) and the external walls are 60-75cm thick. Wiring is exposed, circuits are radial and the consumer units have wired fuses. Main fuse is 80 amp. I've consulted the electricity provider who confirm that this is O.K and that it will uprate the main fuse if necessary.The circuits are as follows:-
consumer unit (1)
30 amp - cooker 30 amp - 10 outlets ( 3 double) including immersion heater 5amp - all lighting except hall/landing (120 watts) and outside light (100 watts) 5 amp - outside light (used about 4 times per annum - would hardly be missed. Could it not, anyway, be taken off one of the 20 amp fuses in CU (2) with an intervening 5 amp?)CU (2)
20 amp - 2 double sockets 20 amp - 2 single and one double socket 20 amp - 1 single, one double socket 5 amp - hall/landing lightCU (3)
15 amp - one single 13 amp socketThis probably sounds pretty dire, but the 13 amp sockets on CU (1) mainly power low energy lamps, Tv, pc etc., and the immersion is never allowed to compete with any other major appliance.
What I would like to have done is:-
(1)Move the outside light (or hall/landing) onto the main lighting circuit which, fully loaded, only takes 3 amps, and transfer the immersion to the, then, spare way, with a 15 amp fuse.
(2)Replace CU(3) with a 3 way unit, with a 45amp fuse for the shower,incorporating RCD protection, 15 amps for the washing machine (which has to move into an outhouse to make room for the shower), and
20 amps to replace the existing CU(3).Alternatively, and more economically, I could put all the lighting on the main lighting fuse, leaving 2 spare ways, one of which,with appropriate fuses, RCD and isolating switch, could be used for the shower, and the other for the immersion. The washing machine could be left on its existing circuit; it only! requires drilling through a
60cm wall and connecting to achieve this.Does this sound sensible, feasible, legal? My fear is that someone competent will come, inspect the system, condemn it, and insist on total rewiring, which I neither want nor can afford. After all, I can always take "'Er Indoors" to the swimming pool for a shower.
I'm not overly concerned about safety on existing circuits. They have performed, without mishap, for the 25 years of our occupancy, and we'll be here until we die. Whoever replaces us will receive, as a legacy, details of existing circuits, about which they can make their own judgements.
Some supplementary queries:- Can anyone tell me, please, the approximate physical dimensions of (a)
10mm TWE and (b) a 3 way consumer unit, and advise me whether a 32mm hole would be adequate (and would it be legal) to accommodate two 15mm water pipes and the 10mm cable?Drilling the appropriate holes is something I could do; it makes more sense than paying an electrician for 3 or 4 hours of his time, plus hiring charges, to make two 50 mile journeys in day to hire and return a drill in order to make 2 holes in the outer walls.
One final point. If you're a pro reading this, would you, on arriving at a job to give an estimate, be incensed to find all the required materials awaiting you? I ask because I can probably get a much better deal on the net than he can at his wholesaler.
Any comments or suggestions would be very much appreciated.
Tony.