phil d
Well-known member
Did a board change for a mate,did a few tests beforehand and the results gave me the view that there would be no issue changing the board, it was a small terraced house with only 4 circuits, light up, lights down, one ring and a cooker. I went for a new board with RCBO's as I didn't see the sense in using a split unit for 4 circuits. Anyway I fitted the board, everything checked out and away I went, later on that evening I get a call, there's something weird going on with the lights tripping the RCBO's. I immediately realised what I thought the problem was and drove back to sort it. I was thinking borrowed neutral on the landing light, yes I know I should have checked.
I reset both breakers and tried all the lights, they all worked fine, no trip, which was exactly what it had done earlier when I checked everything, I switched everything back off and headed downstairs, at this point I realised I'd left the landing light on, switched it off and both breakers tripped out. I reset them and tried again, they only tripped when I operated the 2 way in a certain position, given the light worked fine at certain times and not at others I knew it couldn't be a borrowed neutral. Some fool had fed the landing light off the upstairs circuit,but had used a 2 core for the 2 way, the live for the bottom switch came off the downstairs lights. Now considering this house had been rewired about 20 years ago it was obvious that this had been wired like that at the time. At which point did they think it was a good idea to take 2 lives from 2 different fuses to feed each end of a 2 way circuit?
Imagine if someone had pulled the fuse for the upstairs lights, tested the fitting they were planning to work on, found it dead, and started work. If someone had then operated one of the 2 ways, they'd have put a voltage back on the circuit being worked on, with possibly fatal results. Ok I suppose with hindsight I should have remembered to check the 2 way and I didn't, but that still doesn't excuse the allegedly qualified spark who wired the place 20 years earlier.
I reset both breakers and tried all the lights, they all worked fine, no trip, which was exactly what it had done earlier when I checked everything, I switched everything back off and headed downstairs, at this point I realised I'd left the landing light on, switched it off and both breakers tripped out. I reset them and tried again, they only tripped when I operated the 2 way in a certain position, given the light worked fine at certain times and not at others I knew it couldn't be a borrowed neutral. Some fool had fed the landing light off the upstairs circuit,but had used a 2 core for the 2 way, the live for the bottom switch came off the downstairs lights. Now considering this house had been rewired about 20 years ago it was obvious that this had been wired like that at the time. At which point did they think it was a good idea to take 2 lives from 2 different fuses to feed each end of a 2 way circuit?
Imagine if someone had pulled the fuse for the upstairs lights, tested the fitting they were planning to work on, found it dead, and started work. If someone had then operated one of the 2 ways, they'd have put a voltage back on the circuit being worked on, with possibly fatal results. Ok I suppose with hindsight I should have remembered to check the 2 way and I didn't, but that still doesn't excuse the allegedly qualified spark who wired the place 20 years earlier.
