Connecting SWA into a gland

[PaulP59D]

Hi,

I am about to do the whole connecting up the new garden shed/cabin to the mains thing. I am a qualified electrical engineer, but not an electrician.

So, I have taken advice and have gone out and bought some SWA and glands kit and a small consumer unit for the cabin and a connection box to pick up a connection (via a short length of twin and earth) from the crowded consumer unit in the garage.

My most pressing problem is that although I can guess how the SWA should be connected to the glands I cannot actually find any diagrams on the web to confirm my idea of how it should go.

Can anybody point me in the direction of such a diagram? Also the brass tags that come with the glands kit, what are they for? Earthing I presume?

Thanks.

 

[Job_n_knock]

It should be terminated into a metal box...the brass tags are for earthing to the box in case you dont get good continuity. From where the cable enters the box to where the final connections are you should measure allowing for wide sweep bends etc and add a little for good measure, then put a mark on the cable. Take the gland apart and fit the main body to the box securing with lock nut ( dont forget the earth tag...allow the bolt hole of the tag to be near the front of the box for ease of drilling but not so it snags the lid. Cut the shroud to size and slide over the cable, slide on the back of the gland. With a junior hacksaw cut into the outer sheath and halfway through the steel strands as carefully as poss and as straight as you can all the way round where you marked the cable. Strip off the outer sheath at this point. You will find that if you bend just a few of the steel strands at a time they will break easily. Now look at the main body of the gland and especially at the "cone" part, note its length. What you have to do is to push the inner cable through the middle hole and allow the steel strands to slide up the cone. Allow the length of this cone and add about 5mm depending on size of cable. Run a stanley knife around the cable as straight as possible and strip off a section of outer sheath at the same length. Holding the cable in one hand grip the inner sheath with the other and move it in a circular fashion to open up the strands. Then push the cable through and allow the strands to slide up the cone. Keeping held firm, slide the back of the gland up and screw it up as tight as you can. Use a good set of grips to get a good tight fitting. Slide the shroud up and cover the lot. Drill the bolt hole of the "banjo" or earth ring and fit a nut and bolt. Make your connections and Voila you're there.
If Ive missed anything out Im sure someone will be quick to jump in.

 

[PaulP59D]

Thanks, that's a great description and remarkably prompt too. I have two supplementary questions, though - if that's OK?

After I have inserted the cable and run the nut up the conical section am I right in thinking that this will leave steel strands exposed at the bottom of the gland until such time as I slide the rubber cover over the whole thing?

Secondly, going back to the tag, can I connect the SWA directly into the consumer unit in the cabin? This is not made of metal, of course, so bolting the tag to it will not do a lot. The SWA that I have is 3-core, so I anticipated just using one of the cores as an earth within the consumer unit. Do I need to position a metal box outside of the cabin consumer unit? This is actually what I will be doing in the garage, but I was only doing that to avoid attempting to get SWA into the existing consumer unit.

Thanks again for your time.

 

[breezer]

1, yes it will

2, you can try, but there may not be enough room, its quite common to terminate an swa into a (spreader) box first

 

[PaulP59D]

In that case that's what I'll do. Thanks again, you've been a great help.

 

[ban-all-sheds]

Diagrams here along with a link to a topic posted by someone showing his trials and tribulations.

Re connecting to the CU, if you can get a metal adaptable box right next to it, fit the gland there, but leave the SWA cores much longer, and take them through holes in the box (don't forget the grommet) & CU:

 

[PaulP59D]

Thanks for the diagrams. looking at the cable colours in the diagram reminds me of yet another question. I have now taken a piece of the SWA and experimented with connecting it to the gland. I notice that the colours of the 3-cores are brown, black and grey.

Can you tell me what the correct colour convention for this would be. I would suspect brown = line, black = neutral and grey = earth. However, your drawing would seem to indicate grey being used as neutral and black as earth. Is that correct?

 

[plugwash]

by BS7671 either is fine but both must be properly indicated with suitable sleeving.

the niceic tell thier members to use grey=neutral black=earth supposedly to try and break the idea in peoples minds that black is a neutral color. Some of us think this is crazy but the niceic are so powerfull in the industry that thier convention has become the norm.

 

[PaulP59D]

Thanks, it's all becoming clearer.