So I got called out to a tripping breaker last week. 30A old Wylex push button MCB. Client had repeatedly re-energised and reported it stayed on for a while. This is what I found in a back box...
After what I thought was a thorough walk round and some testing, it looked like there were just loads on the circuit, I did energise it whilst clamping the supply... 50A!
Wasn't able to restore full service but went back yesterday and this is what I found during my investigations:-
TT System with a fully functional 100mA upfront RCD which had been disconnected, but left in the on position... client was wondering why it didn't trip when this fault occured.
Ring final circuit with a leg that had been deliberately cut to break the ring with still connected live cable ends left uninsulated in a back box. The circuit was left on the 30A breaker.
Another socket had been taped over with parcel tape by the last 'electrician' to visit because it wasn't working.
When I left, the ring appeared to be in good order with good end to end continuity, the topology appears to be correct (some sockets were a bit high on the R1+R2 front but there is a bit of damp problem - that I suspect has been caused by people rendering inside and out with a strong mortar mix instead of lime render), IR is a bit low at around 2.5-3Mega ohm, RCD has been restored and tested (fully functional) and as far as I can tell all socket outlets have a functioning earth which is a major step forward from when I arrived as I found several with loose or non-existent connections.
The worst of it is, as best as I can tell, it was left in a bad way by a local guy who as far as I can tell has never been registered with a scheme but has been advertising for years offering the full compliment of domestic electrical services. It's not the first time his name has come up when I found some bad work.
Had another case the other day where I was moving a socket outlet. Started testing and shocker, the results were in some cases not at all like the certificate (they had a CU change back in June)... all circuits recorded having an IR of 200 Megaohms. I only found one that had anything like that, and on one half of the board, none of them had an IR of much over 3Mega ohms. And why was the board change sold to them? Because plastic boards are now illegal and they needed RCD protection for the lights in the bathroom (true) and their new mixer shower (true). But given they already had RCD protection on the socket circuits, both could have been supplied as spurs from the socket circuit... but hey how, plastic boards are now illegal so I can see a lot of board changes coming my way!!! FFS
Again, in that case a name came up that I've run across before, again in relation to some dodgy work. Does my head in!
mg_smile:
Appreciate I may have put off anyone coming round to my place for a BBQ
