Tim Howard
Well-known member
Another local sparks who I'm good friends with asked me to look at this one with him.
He'd gone there to try and solve nuisance tripping. Based on testing he reckoned the car port electrics were a big factor (I could certainly see why) and he replaced some accessories with decent IP rated fittings, removed the dead slugs etc.
Long story short, he was was getting L-E IR of 0M but only when all sections of the circuit were connected, and bewilderingly all sections tested clear if tested independently.
So we got there today and I was given the tour. The state of the place left me rather speechless. I don't think I've ever seen such a wilfully created mess (farms excepted)
TAILS:
Yes this really is all outside!!
The service head is under there....
SWA to car port is just lying on the ground, with a pile of mud, broken slates and felt on top of it:
We agreed the strategy would be to try and make sense of the test results, ensure anything he'd touched was safe, and get out of there touching as little else as possible. (We had a conversation about the state of things too)
Long story short the N for the circuit had been in the wrong N bar all along which led to some interesting / confusing test results.
Right at the beginning, he turned RCD1 off and did L+N to E and got zero, so understandably went looking for dodgy things, and there were plenty to choose from. At some point he disconnected the mid-circuit joint box to allow the house power to go back on, and work on the end section until that tested clear.
He then had clear test results the load side, and clear L-E results the supply side (with MCB off).
The point of confusion that really threw him was when you connect it together again, you will get L-E of zero if any loads are in circuit and if the apparently completely unrelated 2nd RCD is turned on:
Further confusion was that we started with the main switch off and couldn't initially reproduce any of his results! Very luckily someone moaned about needing wifi and we put half the board on, and the strange results appeared again.
He'd gone there to try and solve nuisance tripping. Based on testing he reckoned the car port electrics were a big factor (I could certainly see why) and he replaced some accessories with decent IP rated fittings, removed the dead slugs etc.
Long story short, he was was getting L-E IR of 0M but only when all sections of the circuit were connected, and bewilderingly all sections tested clear if tested independently.
So we got there today and I was given the tour. The state of the place left me rather speechless. I don't think I've ever seen such a wilfully created mess (farms excepted)
TAILS:
Yes this really is all outside!!
The service head is under there....
SWA to car port is just lying on the ground, with a pile of mud, broken slates and felt on top of it:
We agreed the strategy would be to try and make sense of the test results, ensure anything he'd touched was safe, and get out of there touching as little else as possible. (We had a conversation about the state of things too)
Long story short the N for the circuit had been in the wrong N bar all along which led to some interesting / confusing test results.
Right at the beginning, he turned RCD1 off and did L+N to E and got zero, so understandably went looking for dodgy things, and there were plenty to choose from. At some point he disconnected the mid-circuit joint box to allow the house power to go back on, and work on the end section until that tested clear.
He then had clear test results the load side, and clear L-E results the supply side (with MCB off).
The point of confusion that really threw him was when you connect it together again, you will get L-E of zero if any loads are in circuit and if the apparently completely unrelated 2nd RCD is turned on:
Further confusion was that we started with the main switch off and couldn't initially reproduce any of his results! Very luckily someone moaned about needing wifi and we put half the board on, and the strange results appeared again.
