Unconventional termination of SWA

[Tony S]

Carp lyrics but 10 out of 10 for the sentiment.

 

[SLIPSHOD & SLAPDASH]

To increase the surface area of the gland ,  is what we were told .         Its strange  you say that ,  I , and anyone I know in the trade  since the 1960's  have never seen them on the inside ....perhaps it changes by  location .   :C

There are a few  anomalies that you come across perhaps once only .

One I always quote  was a hospital  wards refurb we did ...the spec demanded  the use of , when coupling to a surface box...a flanged coupler   ( steel conduit)   complete  with long reach 20mm bush with a serrated washer on it  .on the inside   ....and a lead washer  between the flange & the box .     All very well  but never , ever did it again .

This was B/E conduit  but theres a Google picture  so someone must still use them ...shows the lead washer but not the serrated washer. 

View attachment 9662,,

We had to use these 100% of the time on   BT jobs, that was about 15 years ago. I wonder what H&S would   say today.

Back to the op, what about street lighting cutouts, no glands & a jubilee clip round the swa.  I was taught a similar method,  on my apprenticeship, slipping a pipe under the swa and a jubilee clip in certain   tight areas, 

 

[Evans Electric]

OH  BT were using them too then !  

Yes street lighting was a problem we had too .  Wiring in SWA  , a metal spur was spec'd  to be fitted inside the lampost service point  but you couldn't get two pair of grips in there to fit a gland  .  The only way was to have a big loop sticking out , gland up onto the box and shove all the slack  into the lampost .   Having a loop in & out was even worse .  

These were the more decorative lamposts  , not much room,     used for university campus   pedestrianised areas and walkways  , hundreds of 'em .       That was the job we asked about using split concentric   and were informed we were not allowed to install it .   

I'd bet if the city council  or the local electric  board  were doing the job ...they'd have used it !!!    

 

[Evans Electric]

Talking about unconventional  termination of SWA's    ...I just remembered  doing some work for British Gas  on their remote stations  .   

Their method of making off SWA   was the usual way ,  row of armoureds in the top of a panel  ....then about  6 - 8 inches  above the gland  they cut a band of PVC out of the sheaths  about 20mm wide  and strap all the SWA 's together with copper strip  clamped onto the armouring .   :C

I didn't emulate the method as I thought it was stupid TBH   .

They did however have a great method with their  really high   lighting columns .   Attach  this hydraulic device at the bottom ,  shove a lever in to lift the top half of the column off the base , then lower it against the hydraulics  .     Do your work on the floods at the top then pump it back up .   

 

[Tony S]

Back to the op, what about street lighting cutouts, no glands & a jubilee clip round the swa.  I was taught a similar method,  on my apprenticeship, slipping a pipe under the swa and a jubilee clip in certain   tight areas, 

It’s a very common way of terminating SWA’s, the “top hat gland” supports the cables armouring. I had many an argument with E54 about them.

A few years back I had to look in to having 11kV PILC-SWA cables terminated, top hat glands and heat shrink tubing to the rescue.

Their method of making off SWA   was the usual way ,  row of armoureds in the top of a panel  ....then about  6 - 8 inches  above the gland  they cut a band of PVC out of the sheaths  about 20mm wide  and strap all the SWA 's together with copper strip  clamped onto the armouring .   :C

Very common back in the 60's.

 

[Evans Electric]

Very common back in the 60's.

Who  was that then   Tony  ?  This was British Gas  .   Can't say I ever saw it done until  the 1990's . 

My thoughts on it were :- 

1.  What does it achieve ?  Nothing . 

2. The glands  &  banjo's bolted to the top plate were more than adequate  and conformed with common practice .

3.  Exposing the armour wires to the elements  is not to be recommended  in any way . 

4.  Squashing  the cores with a clamp is not common practice .

 

[Tony S]

I can think of a couple of companies I’ve worked for that used copper tape between SWA’s. It doesn’t mean I agree with the method. When I first saw it used I couldn’t see the point of it and I still can’t.

 

[Evans Electric]

I can think of a couple of companies I’ve worked for that used copper tape between SWA’s. It doesn’t mean I agree with the method. When I first saw it used I couldn’t see the point of it and I still can’t.

Its as pointless  as those  PVC conduit adaptors  with a moulded boss on the side .     Apparently its for a self tapper to fix an  earth lug  to :C  

 

[kerching]

Its as pointless  as those  PVC conduit adaptors  with a moulded boss on the side .     Apparently its for a self tapper to fix an  earth lug  to :C  

Well I actually thought it was for sticking a self tapper in to "lock" the conduit in the "style of the 'American system " where they do not thread the conduit

 

[Evans Electric]

It could be  that ....  I just  remember asking  and thats what I was told .    I'm surprised they still do that moulding TBH  .      Hey!  Thinking about it ...  isn't there a boss in the PVC  conduit boxes  for "earthing"   ?   

 

[kerching]

It could be  that ....  I just  remember asking  and thats what I was told .    I'm surprised they still do that moulding TBH  .      Hey!  Thinking about it ...  isn't there a boss in the PVC  conduit boxes  for "earthing"   ?   

 I think you can buy a terminal to push fit into it for joining the earth wires together

 

[Pete10001]

I suppose it's academic now as if installing a new circuit in SWA to a CU, it seems the current regs would require a change of said CU to metal clad anyway. Is that correct?

I am a bit rusty lol!!

No CU change required, gland the SWA into the enclosure as normal, use a Piranha lock nut and earth the Armour via a suitable size lead from the nut to the earth bar, as you normally would