Type of 3 Phase supply cable?

davesparks · May 11, 2014

There you go, it's as simple as that. The DNOs cable is the DNOs problem, if you suspect something is wrong you call them out to deal with it.

I'm curious as to what is wrong with the termination? Do you have any pictures?

Engineer54 · May 12, 2014

It had been installed a long time ago but is Red, Yellow and blue phase colours, it obviously has pvc covering over the copper, then half of the circumference has steel armouring used as the neutral then another layer of pvc.

This description doesn't sound like a TN-S ''Split Concentric'' to me, ...it sounds like a concentric TNC-S. The so called steel armouring is probably tinned copper, though i've never seen bare tinned neutral copper conductors in this cable type, others here may have....

davesparks · May 12, 2014

My best guess on it is that it is split concentric with black insulated neutrals which haven't been noticed. Bearing in mind the op didn't see it but is working on 2nd hand info. And he only saw it through a bad termination apparently, not sure what he means by that though.

Knobhead · May 12, 2014

If it’s a DNO 3Ph TN-C-S supply it will be concentric wavecon.

As for as for safe zones, RCD’s, etc. It’s got nothing to do with you or BS7671 so leave it alone.

Engineer54 · May 13, 2014

davesparks said:
My best guess on it is that it is split concentric with black insulated neutrals which haven't been noticed. Bearing in mind the op didn't see it but is working on 2nd hand info. And he only saw it through a bad termination apparently, not sure what he means by that though.

Not from the way the Opening post has been written it's not second hand info!! As far as i can see, the OP has little to no idea what he's looking at...lol!!