"Andy Hall" wrote in message
...
On Wed, 10 Sep 2003 00:12:22 +0100, "Andy Wade"
wrote:
"Andy Hall" wrote in message
.. .
I thought of simply bringing the SWA into the back of the CU,
running the red and black core cables to the incomer breaker.
However, this does not seem that mechanically satisfactory. I can
clip the cable as far as a point close to the entry through the
back.
An alternative idea is to use a metal box with 20mm knockouts at
both ends. This would be fitted in the cavity (screwed down) and
use a gland to terminate the SWA cable with the conductors going
into a 30A terminal block. 6mm^2 T&E would continue from there
into the CU.
Has anyone had to deal with a similar situation, and come up with a
neat solution?
Could you mount an adaptable box close up to the CU housing (directly
behind
it, say) and couple it mechanically with a long pattern conduit bush
(would
probably need to be 25mm) and a few lockrings? Then take the SWA into
the
adaptable box with a gland in the usual way, and feed the L&N thro' the
bush
and into the CU itself.
Hmmm. Yes that does seem like a good solution and certainly solid.
It's not clear whether you're using the armour to provide an earth or
whether you need to isolate it at this end because the summer house will
be
a TT system. If the latter, a plastic adaptable box may be preferable to
metal (since the armour should be considered as potentially live within
the
separately earthed zone, IYSWIM).
Yes, I see what you are saying. I hadn't really decided whether to
separately zone it. Since it is close to the house, I was thinking
more in terms of exporting the earth through the armour in this
particular case. In this case I'd add in an earth wire from the gland
tag to the earth bus bar of the CU.
Do you have a suggested way of terminating onto the tag? On a metal
CU it seems to be common practice to bolt through the small hole of
the tag to the CU metalwork and then from a terminal on the case to
the earth busbar. A nut and bolt for the wire directly onto the tag
does not seem very good mechanically, so perhaps a soldered joint?
.andy
You should have been given a brass earth tag when you bought the glands for
the SWA. Yes ? Then you will fit the brass tag (that's the thing with a
big hole in one end and small hole at the other) over the threaded end of
the brass gland before you stick it through the hole you've drilled for the
fitting, and then tighten it in with the locking nut of the gland. Next
you'll need the two nuts, the four washers and the one bolt you bought when
you got the rest of the fittings. You did get them, didn't you ?
Anyway. You can now drill a hole through the box and through the small hole
of the brass earth tag. Yes, that's right, so you can bolt the small hole
end of the earth tag to the side of consumer unit too. You only use two
washers at this bit, one on the outside and one on the inside. Then you put
one of the nuts on and tighten it all up so you make a sandwich of the wall
of the consumer unit. Next. Take another washer and put it on top of the
nut on the inside of the box. You then take the 6 mm green/yellow insulated
cable you got, you did get that as well, didn't you ?
Anyway. You crimp on the loop to one end of 6 mm cable and then slip it
over the bolt. What do you mean "I didn't get any crimp on loop" well this
is were you're you gonna' need one to do the job right. OK. You've now got
the crimp on loop on the end of the 6 mm green/yellow cable. Right. You
put the last washer on the top of that, and then the last nut on the top of
that.. Don't tighten it up to far just now though, as you've got the other
end of the cable to terminate.
Trim down the cable to the length you need and slip off some insulation,
enough to let you connect into the earth bar of the consumer unit. Yes, the
brass bar thing screwed to the side with all the holes and bolt in it. No
!!! Not the one for the neutrals, the other one. Now, you've got that end
secure, you can go back and tighten up the nut and make sure that the cable
isn't fouling anything and that the lid will go back on without mishaps.
Right !!! You're ready to tackle the red and black conductors to the main
switch now ? Good !!!
Now !!! What about the other end of the SWA. :-))
---
http://www.basecuritysystems.no-ip.com
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (
http://www.grisoft.com).
Version: 6.0.516 / Virus Database: 313 - Release Date: 01/09/03