S
SirKit Breaker
A bit of a strange one.
Second fixed downlights to a new kitchen ceiling after it had been skimmed and painted, no problems everything tested OK both live and dead,
During week plasterer returns and re plasters all the walls. He has used metal angle bead on all the external corners. Where they go floor to ceiling they stop at the ceiling and about 2 inch before floor level, and can not be in contact with any cables or pipework.
I know for a fact that where he has nailed the corners on there are and have never been any cables, because i saw the wall back to brick before he started.
The Stop cock and gas meter are about 6 inch from the nearest piece of angle bead, but the bead is not touching either.
I get a phone call from kitchen fitter, he has bent down to turn stopcock off, and leant against the wall with his hand at the same time touching the anglebead, from which he gets an electric shock bad enough for him to have to sit down for half an hour or so.
I return to investigate, the anglebead only goes live when one set of the downlights are turned on at the switch, in all other conditions there is no voltage present. The lighting throughout the house is loop in live at the switches and loop in neutral at the pendants, all done in single black and single red and earth 12 years ago as part of a rewire after a lightning strike. There are 2 lighting circuits, up and down, and the neutral is not shared.
I have done all the additions and alterations since the rewire including a 16th CU upgrade about 5 years ago. I didnt do the rewire but it has been done to a high standard, and i know the contractor that did it, he had a good reputation until his recent death.
What I have done.
Confirmed 231 volts between this and 3 other pieces of angle bead and the bonded pipework.
Confirmed that both water and gas are bonded correctly and at the required size.
Confirmed that there are no wiring problems with the down lights above the ceiling both visually and electrically ( I have wired it in such a way that i can access all connections including the reused loop connections which i have extended from with Helacons).
Ze for TNCS is OK, as is the Zs of the lighting circuit, this is still protected by a 60898 6A mcb, but a RCBO is going in to replace it.
There are several new circuits in the kitchen which i have installed but neither ends of the cables are connected to anything.
All the plaster is dry, so nothing can be tracking through it.
I carried out an IR test between the anglebead and stopcock, in excess of 500meg, lighting circuit live to stop cock (did both sides of switch), in excess of 500meg, anglebead to lighting live, again above 500 meg, lighting earth to stopcock 0 meg.
I have bonded the angle beads to the pipework and the problem has gone away and everything works as it should. But i cant get my head around what was wrong and how this beading is getting up to mains voltage unless its bonded.
Answers, opinions and explanations greatly accepted.
Cheers............Howard
Second fixed downlights to a new kitchen ceiling after it had been skimmed and painted, no problems everything tested OK both live and dead,
During week plasterer returns and re plasters all the walls. He has used metal angle bead on all the external corners. Where they go floor to ceiling they stop at the ceiling and about 2 inch before floor level, and can not be in contact with any cables or pipework.
I know for a fact that where he has nailed the corners on there are and have never been any cables, because i saw the wall back to brick before he started.
The Stop cock and gas meter are about 6 inch from the nearest piece of angle bead, but the bead is not touching either.
I get a phone call from kitchen fitter, he has bent down to turn stopcock off, and leant against the wall with his hand at the same time touching the anglebead, from which he gets an electric shock bad enough for him to have to sit down for half an hour or so.
I return to investigate, the anglebead only goes live when one set of the downlights are turned on at the switch, in all other conditions there is no voltage present.
The lighting throughout the house is loop in live at the switches and loop in neutral at the pendants, all done in single black and single red and earth 12 years ago as part of a rewire after a lightning strike. There are 2 lighting circuits, up and down, and the neutral is not shared.I have done all the additions and alterations since the rewire including a 16th CU upgrade about 5 years ago. I didnt do the rewire but it has been done to a high standard, and i know the contractor that did it, he had a good reputation until his recent death.
What I have done.
Confirmed 231 volts between this and 3 other pieces of angle bead and the bonded pipework.
Confirmed that both water and gas are bonded correctly and at the required size.
Confirmed that there are no wiring problems with the down lights above the ceiling both visually and electrically ( I have wired it in such a way that i can access all connections including the reused loop connections which i have extended from with Helacons).
Ze for TNCS is OK, as is the Zs of the lighting circuit, this is still protected by a 60898 6A mcb, but a RCBO is going in to replace it.
There are several new circuits in the kitchen which i have installed but neither ends of the cables are connected to anything.
All the plaster is dry, so nothing can be tracking through it.
I carried out an IR test between the anglebead and stopcock, in excess of 500meg, lighting circuit live to stop cock (did both sides of switch), in excess of 500meg, anglebead to lighting live, again above 500 meg, lighting earth to stopcock 0 meg.
I have bonded the angle beads to the pipework and the problem has gone away and everything works as it should. But i cant get my head around what was wrong and how this beading is getting up to mains voltage unless its bonded.
Answers, opinions and explanations greatly accepted.
Cheers............Howard
