jimster99. Good evening Sir.
We are a nosy crowd and really like to know about how problems which have been presented are resolved especially when we have 'skin in the game'.
I noticed that the light fitting has been replaced some time which may be significant. We will not ask by whom. What we really want to know is whether this problem has been first explained and second resolved so that it is safe for all. Unless one understands how you received the shock ie explained by careful investigation it is uncertain whether it could happen again.
Hello Marconi! Thanks for the reply (and for your earlier very helpful comment that damp socks = no static!) and don't worry, I have not forgotten about this - I am very keen to avoid future shocks!
The light itself had been replaced by somebody before we moved into the property. We don't know who!
The outstanding points appear to be:
(i) checking the RCBO: why didn't it trip? I suspect because I got less than the 30ma trip level. It's worth noting that we had a faulty metal electric kettle a few months ago that DID trip the RCBO a few times, although I suppose it could have been a short circuit tripping the fuse rather than a voltage leak. But this should be checked (which requires taking the front of the RCBO box off).
(ii) Is the internal wiring of the LED itself correct? You asked for a photo of the inside of the light and I will do this when I get a moment (hopefully today). I have the VED screwdrivers ready to go!
(iii) should the internal lugs of the switch be bent back to avoid any future risks of electric shocks? EDIT - yes - and I will do this myself (since the electrician didn't) after cutting the power to the entire property.
(iv) check earth continuity back to board.
(v) The earthing resistance needs to be checked which requires a fault loop impedance test.
Is this the same thing as (iv)?
(vi) an insulation test needs to be carried out on the circuit (rather than just the switch) which requires taking the front cover off the RCBO.
Odd. Carrying out an insulation test on the circuit (as distinct from the switch) requires taking the front off the board to disconnect the neutral. In which case an RCD test can be done at the same time, taking less than a minute. If he did not test the circuit insulation and did not open the board, then it is still possible to do the RCD test from the switch position albeit with a bit of legwork to visit the board a few times to reset the RCD.
Hmm, he only checked the switch insulation, not the circuit insulation. Shall i get him to come back and check the circuit as well? He didn't seem to think it was a necessary check but better safe than sorry I think!
There's a remote possibility that it's the floor that is 'live' as a result of a nearby fault, and that the shock came from touching correctly earthed metal in the switch.
I hope this can be ruled out because of the fact that the light itself was intermittlently pulsing when switched off shortly before the shock - too much of a coincidence otherwise.