Hi there,
My first post on this forum, although I have been reading it with interest for quite a long time. As background, I live in a very large house with a complex electricity installation, most of which is fairly modern. I have a reasonable understanding of the 17th Edition wiring regs and Part p.
To cut a long story short, one of the CUs ideally needs to be repositioned. It is high up on a wall with all circuits wired on (short) drops from the ceiling. It (Dual RCD + Main swith) currently serves 8 final circuits, 3 of which are rings, so there are 11 final circuit cables in total. It really just needs to be repositioned 4-5 feet below it's present position.
Needless to say, the problem is that none of the existing finals cables would reach the new position, and gaining access to rewire all of them to their first point of termination would be extremely (I would say prohibitively) distruptive in terms of gaining access. The effect of lowering the CU would be to shorten the required length of MEB and meter tails, so that's not an issue.
Frankly, I would not contemplate the CU move at present if it required replacing the final runs of cables on all circuits - and would probably delay the exercise unless/until many of the carpets and floors are up for other reasons. I therefore wonder what views are on the alternative strategy of extending all of the 11 cables from their present position (near ceiling) to the new position. In as much as all the junction boxes (or whatever) would be accessible for inspecton (and might even be of assistance to testers in future!), it looks to me as if this should be OK with the regs, but I wonder what people think, and what view is likely to be taken of such an installation.
Secondly, if this extension approach were taken, I wonder what would be the most sensible and neatest way to do it. Eleven separate JBs (maybe slighly less if 6-terminal ones were used for some of the lower current circuits) would obvioulsy be a bit messy and cumbersome, although not impossible. What about suitable connector blocks in suitable enclosures? - or are there any "very many way" JBs available for this sort of situation?
I realise that what I'm suggesting is not ideal, but it would be practical - and if it were done, I'd probably arrange for the final cables to be re-done properly as/when access had been created for other reasons.
I look forward to hearing thoughts on this.
Cheers, John
My first post on this forum, although I have been reading it with interest for quite a long time. As background, I live in a very large house with a complex electricity installation, most of which is fairly modern. I have a reasonable understanding of the 17th Edition wiring regs and Part p.
To cut a long story short, one of the CUs ideally needs to be repositioned. It is high up on a wall with all circuits wired on (short) drops from the ceiling. It (Dual RCD + Main swith) currently serves 8 final circuits, 3 of which are rings, so there are 11 final circuit cables in total. It really just needs to be repositioned 4-5 feet below it's present position.
Needless to say, the problem is that none of the existing finals cables would reach the new position, and gaining access to rewire all of them to their first point of termination would be extremely (I would say prohibitively) distruptive in terms of gaining access. The effect of lowering the CU would be to shorten the required length of MEB and meter tails, so that's not an issue.
Frankly, I would not contemplate the CU move at present if it required replacing the final runs of cables on all circuits - and would probably delay the exercise unless/until many of the carpets and floors are up for other reasons. I therefore wonder what views are on the alternative strategy of extending all of the 11 cables from their present position (near ceiling) to the new position. In as much as all the junction boxes (or whatever) would be accessible for inspecton (and might even be of assistance to testers in future!), it looks to me as if this should be OK with the regs, but I wonder what people think, and what view is likely to be taken of such an installation.
Secondly, if this extension approach were taken, I wonder what would be the most sensible and neatest way to do it. Eleven separate JBs (maybe slighly less if 6-terminal ones were used for some of the lower current circuits) would obvioulsy be a bit messy and cumbersome, although not impossible. What about suitable connector blocks in suitable enclosures? - or are there any "very many way" JBs available for this sort of situation?
I realise that what I'm suggesting is not ideal, but it would be practical - and if it were done, I'd probably arrange for the final cables to be re-done properly as/when access had been created for other reasons.
I look forward to hearing thoughts on this.
Cheers, John
Yes the CPC's should be individual or else there will be a bit of testing at the CU and a bit of testing at the adaptable box, where would you rather be doing it?
