- Sep 24, 2013
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- If you're a qualified, trainee, or retired electrician - Which country is it that your work will be / is / was aimed at?
- United Kingdom
- What type of forum member are you?
- Practising Electrician (Qualified - Domestic or Commercial etc)
- Business Name
- Dovecote Electrical
I had a case today where, if I'd not done things properly, I would have ended up with exactly the same outcome, just saved myself half an hour or so of my time.
Swapping a couple of horrible fancy ceiling lights for standard ceiling rose (landing) and integral LED light (bathroom). Upstairs lighting circuit protected by 6A RCBO, also supplies alarm. Always do tests before tinkering (unless recent credible cert), so quick IR test, (L+N) to E: tester voltage won't go above about 20V, sign of a very low IR. Continuity about 6kΩ N to E: surprised the RCBO not tripping! (RCD test ok).
Start with usual suspects.
- Make sure RCBO fully disconnected.
- Alarm system? Disconnect. No.
- Funny timer switch thing (guess the sort of thing you use when you're on holiday to make it look like you're in, fits on a standard pattress)? Disconnect. No.
- Outside light? No, spurred off socket circuit.
- Manky-looking bathroom fan? SFCU (DP). No.
- Ooh, some standard ceiling roses, easy to have a look? No, they all look good.
- Access to loft? Just about do-able. Poke head up. Looks neat and tidy, no evidence of vermin or joint boxes. Can't see everything though. Hmm.
Alright, I know how this works - break the circuit down. Where's easiest/best guess for roughly the middle? Yeah, probably the landing light. Well, I guess, since I'm meant to be replacing it anyway...
Dear lord. Apparently, the person who replaced the original ceiling rose didn't have any connector blocks. But they did manage to extract the uninsulated terminals from the old ceiling rose, and wrap them with (now very brittle) insulation tape. Rip it all out. 707MΩ. That'll do.
Same thing on the bathroom light, though wasn't contributing to the fault.
Thing is... not sure what I would do different next time.
Was part of a bigger job so the lost time could be absorbed. I really enjoy fault-finding, don't get me wrong. But when you're only doing a small job, doing the proper tests and revealing demons that you need to sort out can add a lot of time, relatively - I just feel a bit awkward, as I sometimes wonder if the client thinks I'm taking them for a ride. I guess building up the trust is the way to go.
Apologies for the Friday brain dump. Anyway - all sorted.
Swapping a couple of horrible fancy ceiling lights for standard ceiling rose (landing) and integral LED light (bathroom). Upstairs lighting circuit protected by 6A RCBO, also supplies alarm. Always do tests before tinkering (unless recent credible cert), so quick IR test, (L+N) to E: tester voltage won't go above about 20V, sign of a very low IR. Continuity about 6kΩ N to E: surprised the RCBO not tripping! (RCD test ok).
Start with usual suspects.
- Make sure RCBO fully disconnected.
- Alarm system? Disconnect. No.
- Funny timer switch thing (guess the sort of thing you use when you're on holiday to make it look like you're in, fits on a standard pattress)? Disconnect. No.
- Outside light? No, spurred off socket circuit.
- Manky-looking bathroom fan? SFCU (DP). No.
- Ooh, some standard ceiling roses, easy to have a look? No, they all look good.
- Access to loft? Just about do-able. Poke head up. Looks neat and tidy, no evidence of vermin or joint boxes. Can't see everything though. Hmm.
Alright, I know how this works - break the circuit down. Where's easiest/best guess for roughly the middle? Yeah, probably the landing light. Well, I guess, since I'm meant to be replacing it anyway...
Dear lord. Apparently, the person who replaced the original ceiling rose didn't have any connector blocks. But they did manage to extract the uninsulated terminals from the old ceiling rose, and wrap them with (now very brittle) insulation tape. Rip it all out. 707MΩ. That'll do.
Same thing on the bathroom light, though wasn't contributing to the fault.
Thing is... not sure what I would do different next time.
Was part of a bigger job so the lost time could be absorbed. I really enjoy fault-finding, don't get me wrong. But when you're only doing a small job, doing the proper tests and revealing demons that you need to sort out can add a lot of time, relatively - I just feel a bit awkward, as I sometimes wonder if the client thinks I'm taking them for a ride. I guess building up the trust is the way to go.
Apologies for the Friday brain dump. Anyway - all sorted.
