- Reaction score
- 2,115
Am currently pondering the following situation:
- Single phase PVC board, domestic, in an area where TN-C-S is the norm (underground supply etc).
- Most circuits protected by 30mA RCD, except lights (B6 60898 MCBs).
- Pre-checks before simple job (on garage circuit) reveal no earthing conductor (10mm bonding to gas, 6mm bonding to water with loose clamp - upgraded to 10mm with new clamp while I was there)
- Zs @ DB = 27.1Ω
- Happysteve notes lots of shiny metal light switches, and rather old looking metal light fittings. Board looks like a 1990's DIY special (the BS951 clamp on the end of the SWA supplying the garage, for instance).
- Have chat with customer about necessity of having an earth, explain WPD will charge for this, they are happy to get WPD to provide one. Phone WPD on behalf of customer, get the ball rolling.
- As a temporary measure, to provide shock (and fault) protection, move 2x lighting circuits to 1x B6 on RCD-protected side of board.
- All circuits now protected by 1x 30mA RCD (same as having an RCD main switch).
Question is, when I go back to the job (to do the actual "simple job") after WPD supply a reliable earth, do I move the lighting circuits back to the non-RCD side of the board? Would not comply with current regs on at least 2, possibly 3 counts (cables buried in wall, domestic lighting circuit, possibly bathroom but haven't checked for supplementary bonding)* but on the other hand would be no worse off than before I made the "distress change". Board is Steeple - not sure on availability of RCBOs (and probably wouldn't fit anyway), could put the lighting circuits on a couple of RCD spurs I guess.
Think of it this way: if earthing/bonding had been in place, and I'd been working on a circuit other than a lighting circuit, I would have left them alone; and the only reason I moved them was I couldn't in good faith have left it like that, given the very real shock risk due to the presence of a single fault on an installation that didn't give me confidence it was installed professionally.
Any thoughts? I'm not going to lose any sleep over this, and I'll probably have a couple of weeks to mull it over!
* Edit: clearly 3 counts, even if there was supplementary bonding. Head was in "EICR mode", sorry!
- Single phase PVC board, domestic, in an area where TN-C-S is the norm (underground supply etc).
- Most circuits protected by 30mA RCD, except lights (B6 60898 MCBs).
- Pre-checks before simple job (on garage circuit) reveal no earthing conductor (10mm bonding to gas, 6mm bonding to water with loose clamp - upgraded to 10mm with new clamp while I was there)
- Zs @ DB = 27.1Ω
- Happysteve notes lots of shiny metal light switches, and rather old looking metal light fittings. Board looks like a 1990's DIY special (the BS951 clamp on the end of the SWA supplying the garage, for instance).
- Have chat with customer about necessity of having an earth, explain WPD will charge for this, they are happy to get WPD to provide one. Phone WPD on behalf of customer, get the ball rolling.
- As a temporary measure, to provide shock (and fault) protection, move 2x lighting circuits to 1x B6 on RCD-protected side of board.
- All circuits now protected by 1x 30mA RCD (same as having an RCD main switch).
Question is, when I go back to the job (to do the actual "simple job") after WPD supply a reliable earth, do I move the lighting circuits back to the non-RCD side of the board? Would not comply with current regs on at least 2, possibly 3 counts (cables buried in wall, domestic lighting circuit, possibly bathroom but haven't checked for supplementary bonding)* but on the other hand would be no worse off than before I made the "distress change". Board is Steeple - not sure on availability of RCBOs (and probably wouldn't fit anyway), could put the lighting circuits on a couple of RCD spurs I guess.
Think of it this way: if earthing/bonding had been in place, and I'd been working on a circuit other than a lighting circuit, I would have left them alone; and the only reason I moved them was I couldn't in good faith have left it like that, given the very real shock risk due to the presence of a single fault on an installation that didn't give me confidence it was installed professionally.
Any thoughts? I'm not going to lose any sleep over this, and I'll probably have a couple of weeks to mull it over!
* Edit: clearly 3 counts, even if there was supplementary bonding. Head was in "EICR mode", sorry!
