... or why conduit through walls is "a good idea"
At church we had a couple of occasions when a fuse blew, but on repairing it (rewireable 15A in ceramic carrier) it was fine again. Of course, finding the fault would have entailed a certain amount of work as no-one knows where anything runs (or at least, that was the case). Then one day, someone mentioned that a socket wasn't working.
The non-working socket was a spur with 2.5mm² in harmonised colours, off a radial wired in (I think) 7/.036 - roughly 4.5mm². Found that this bit of 2.5 had a very very low IR, and the L conductor was open circuit. At the time I found this I didn't have time to fix it, so disconnected the spur.
The other week I got to have a go at it, and when I pulled the old cable out, the problem was "fairly obvious" See if you can spot it
Clearly something has compromised the insulation and it's festered away until it's finally "blasted clear". On closer inspection, it looks rather like our little rodent friends have been snacking on it.
At first I thought the cable might have been damaged when it was pulled in. We decided to fit some conduit which meant drilling a bigger hole, and it's clear that a lot of the stones in the wall are a bit flinty with some very sharp edges - and the cable had been just put through the wall with no protection. But from the picture above, I think it looks more like rodents.
Of course, with a 200 year old lime and rubble wall, just "popping the long drill bit through" isn't anything like modern brick or block. So I've now had my first experience of filling in large holes with lime mortar, and patching the lime plastering. It needed patching before I had a go at it (the previous work had left things a bit fragile), but it needed even more when I'd finished with the big drill Conveniently, one of the churchwardens has been in the building trade and worked with lime construction before - so it wasn't quite a case of "well the videos on the internet say ..."
At church we had a couple of occasions when a fuse blew, but on repairing it (rewireable 15A in ceramic carrier) it was fine again. Of course, finding the fault would have entailed a certain amount of work as no-one knows where anything runs (or at least, that was the case). Then one day, someone mentioned that a socket wasn't working.
The non-working socket was a spur with 2.5mm² in harmonised colours, off a radial wired in (I think) 7/.036 - roughly 4.5mm². Found that this bit of 2.5 had a very very low IR, and the L conductor was open circuit. At the time I found this I didn't have time to fix it, so disconnected the spur.
The other week I got to have a go at it, and when I pulled the old cable out, the problem was "fairly obvious" See if you can spot it
Clearly something has compromised the insulation and it's festered away until it's finally "blasted clear". On closer inspection, it looks rather like our little rodent friends have been snacking on it.
At first I thought the cable might have been damaged when it was pulled in. We decided to fit some conduit which meant drilling a bigger hole, and it's clear that a lot of the stones in the wall are a bit flinty with some very sharp edges - and the cable had been just put through the wall with no protection. But from the picture above, I think it looks more like rodents.
Of course, with a 200 year old lime and rubble wall, just "popping the long drill bit through" isn't anything like modern brick or block. So I've now had my first experience of filling in large holes with lime mortar, and patching the lime plastering. It needed patching before I had a go at it (the previous work had left things a bit fragile), but it needed even more when I'd finished with the big drill Conveniently, one of the churchwardens has been in the building trade and worked with lime construction before - so it wasn't quite a case of "well the videos on the internet say ..."