SWA cables into "consumer" unit

Jun 07, 2010 6 Replies

We have a new Sentry metalcald CU in a small remote building that just supplies some CCTV and lighting equipment, on Two MCB's one at 6 amps the other at 16 supplied by SWA cables. This is replacing an almighty mess thats been there years and is downright dangerous.



The unit in question which is metal has some holes in the bottom which are the same size as SWA glands. I presume its OK to use these to terminate the SWA in directly as it were, taking the Earth banjo directly to the Earth buss bar in the unit and the live and neutral directly to the respective points.



Or as someone suggested earlier you have to take them via something like a metal clad type connector box, with a small connector piece of conduit as they mustn't be directly connected to the unit?. I think he's got that confused with a plastic unit which I suppose you could do this with but as the CU is metal then I can't see any real problem.



Anyone care to comment?..


No problem with SWA into a metal CU provided there's room to get the stuff in without straining things.

You can take them into plastic if you use a pirhana nut to bolt the earth onto - the problem with plastic is it is soft and compressible, so using a banjo with it is a bad idea.

If you are exporting the earth from the supplying building, then this is fine, assuming it all fits nicely.

Are you using the armor as the earth?

How far is the building from the source of power?

Toby...

In article , Toby scribeth thus

Yes as well as one conductor..

Pole mounted transformer within 40 feet!..

Soinds fine then!

I usually fit the earth lug so it is flat against the metal the gland is screwed into, then drill a hole through the metal, and put a bolt through the whole lot, so you just see a bolt head under the CU, then you would attach your extra earthing condictor to this bolt with a crimped ring.

Toby...

That's the way I've seen it done on large 3 phase breaker panels too.

In article , Toby scribeth thus

Good idea that!, dun 'n dusted:))..

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