back today to make a start at fixing this disaster....
upon closer inspection, notice that the shower cable from MCB is a bit burnt....
and it wasnt connected very well at the other end either
also notice that there is a dead short L-E
looks like this is the problem part
moving on, quick test of the lights shows a dead short L-E..
that would be the only screw holding the light to the ceiling. and it didnt actually go into anything else either
also note a lack of earth continuity upstairs, and find this under the floor
wonder what he used to cut the busbar? his teeth?
and i wonder what the point of this was?
few other major things
the earths from his new lighting circuit was connected to the board. along with the earth to most other circuits, although they only went as far the a terminal block half a metre away. there was earthing conductor or bonding (bonding was done, just not connected), so due to the screw through the cable, the earth would have been live at all times, and the RCD/MCB would not have tripped due to no fault current anywhere. also, its probably a good thing he didnt bother to connect the earth from the sockets to the board, otherwise that would have been live (although with a bit of luck it may have been enough fault path to trip the RCD.... either that, or it did trip RCD until they were removed, guess i will never know the answer to that one)
as for the 1.5 feeding the shower CU, there was no need. i simply took the shower cable from shower CU and connected it into the new CU, since it was long enough same with 2 of the other circuits he joined with terminal block to extend
overall, im more surprised that the place didnt burn down, oand that no-one was killed by it