Hi all
Please forgive the OP not being totally clear, but I wanted views which had you known the reason for asking might have influenced you.
The whole story. A customer of an architect friend of mine is proposing a major conversion, extensions at the rear, conversion of the third storey into a guest suite, wholesale replacement and moves of bathrooms, the whole shooting match. They wanted an objective opinion about the state of the electrical installation and the best course of action re the major alterations. The building is a late victorian 3 storey house, always been in domestic occupancy, the 3 phase cable head and cutout are modern, I suspect installed when the last rewire was done, no I don't know why either, 100A fuses, either TNS or TNCS. The board is a Merlin Gerin. They have had signiicant problems with nuisance tripping.
These are the known problems I found
Main earthing conductor 10mm sq
Equipotential bonding appears to be there, but lots of plastic pipes
No supplementary bonding
Study/garage radial wired in 4mm, 45A breaker.
Kitchen final ring in 2.5mm, 45A breaker.
Kitchen radial wired in a mix of 4mm amd 2.5 mm 45A breaker, (fortunately both on same phase).
two lighting circuits both in 1.5 mm, 15A breakers.
Porch double socket sharing immersion heater 15A breaker.
No local isolators on two elec showers, also wired in 6mm sq 45A breakers.
In fact only the gnd and 1st flr final rings have the correct 32A breakers.
Additionally all of the breakers appear to be type C's.
Individual cable cores not sleeved according actual use.
Thats purely from visual inspection, a full PIR may well turn up other nasties.
I have recommended that the costs of puuting it right as well as the additions due to the building works isn't going to be wildy different than a full rewire, in their scheme of things, also they'll get full certification and they won't have to revisit the older parts in a few years time.
Regards
Martin
