Can't connect the SWA cable. Practical help please.

[saveasteading]

My first time hands on with SWA. I've done one end of this cable into an existing box. Slow but successful. 

At the other end the grommet is deeper than the thread and I can't tighten it. If I take the next diameter off the grommet for depth,  the fixing goes straight through. The grommet doesn't compress either.

 

Am I doing something wrong or is there a trick?

 

[JohnMo]

You don't put the metal gland through the grommet. A different junction box would be easier. You need a 20 or 25mm hole and the gland gland goes directly into JB

 

More like this

[saveasteading]

So it's the wrong box, made for multiple cable sizes and the hole is too big? 

I see in your pic, there is a grommet for the small cable.

 

I've a thought. The cable entry is at the bottom and has the supplied shroud so water won't get in. A couple of washers might suffice as tightening surfaces.

[markc]

You wouldn’t be the first to use washers (or an earth tag either side - they are thin). 

[saveasteading]

29 minutes ago, markc said:

earth tag either side

Excellent that was my next plan.   I was disappointed to not find any big washers in my multiple tins of fixings.... they justify keeping even more.

It was useful to remind myself  what I do have though.

[garrymartin]

Not that it will help now, but going into a plastic box, potentially outside, I'd always go with the correct sized Storm gland...

 

https://www.electricpoint.com/swa-storm20s-lsf-armoured-cable-glands-m20-20mm-ip68.html

 

[TerryE]

@saveasteading YouTube is your friend here.  There are  lots of howto videos; watch a few.  One trick that's important is making sure that you cut the SWG sheath neatly and to the right length.  You need to mark the snip line and use a decent pair of wire snips that are man enough for the wire gauge.   I don't know if its the recommended way but I have an old fashioned adjustable pipe that rated up to 28mm copper.  I just cut the outer PVC sleeve with a knife as a guide, then do a dozen + turns to finish cut into the SWG to notch it.  Doing it this way keeps the wire well clamped for the nothing I then cut back the outer sheath to the notch ring and then fatigue break the SWG wires around the notch; cut back the outer to size according to the fitting instructions. Slide the other cover and locking ring  over the wire before rolling around the centre 4 / 4 core to flare the wire sheath so than the gland can easily slide into it.  As I said look at the videos.  After a few fitting, this only takes a few mins mad you will end up with neat jobs like @JohnMo's.

[Onoff]

Use an earth nut to suit, 20/25/32:

 

https://www.tlc-direct.co.uk/Products/PRPEN20.html

 

Check out the Technical & Description bits.

 

[AdamSee]

You need a Wiska box, these are IP 66 rated so suitable for outdoor use. But they have M20 holes on the side so the SWA gland can screw straight onto the box.

 

https://www.tlc-direct.co.uk/Products/WK108B.html

 

I find the best way to get a decent earth connection is to use the spring rings rather than the bulky earth bar clamp.

[Nickfromwales]

36 minutes ago, Onoff said:

Use an earth nut to suit, 20/25/32:

 

https://www.tlc-direct.co.uk/Products/PRPEN20.html

 

Check out the Technical & Description bits.

 

I used those piranha ones on the last job, much easier imho.

[Onoff]

Storm glands another option:

 

https://www.tlc-direct.co.uk/Products/TLST20.html

[saveasteading]

Thanks all. Ill have a proper read through later.

The earth tags just about work in getting a fix, but it's not tight.  The existing box I now see has these fixed size pop- outs as described and the  same make as the photo. ....hence the first one went well. 

The second one is a proper outdoors box from my stores.. def not so good. Probably from Homebase sale 10 years ago. 

 

 

The cable I've replaced looks like bell wire. its amazing it worked so long underground. I've cut it where it runs up the wall, and will later replace it Into the house.

It's also quite brittle  But I've connected it.

 

But the power tripped when I turned it on.

 

Grrrr

 

I'll give it  a look at tomorrow and hope to see where the short is.

 

It shouldn't be difficult but it's all tight for space in the box.

 

 

Any ideas why swa has grey wires not blue?

 

Have I done anything silly?

Brown to brown

Grey to blue

Earth or bare wire to black.

 

 

 

[Onoff]

9 minutes ago, saveasteading said:

Any ideas why swa has grey wires not blue?

 

It's 3 phase cable / colours.

 

[Onoff]

I've got similar. I left brown as L, sleeved the black with blue for neutral and sleeved the grey with green/yellow for earth.

[andyscotland]

1 minute ago, Onoff said:

I've got similar. I left brown as L, sleeved the black with blue for neutral and sleeved the grey with green/yellow for earth.

 

I'd do the same. TBH once you're sleeving cores there's no real requirement to follow any particular colour code but I feel like at least black was neutral in the old UK colours so there's a kind of logic to that. 

 

Just make sure you do sleeve (/tape) the cores at each end so that if someone disconnects one end for some reason it's obvious how to reconnect without having to open up the other to check.

 

And second the recommendation for Storm glands in future.

[saveasteading]

16 hours ago, TerryE said:

YouTube is your friend

I did find a good one and worked to it. To your tips it adds using a hacksaw for the first sleeve cut, then the armour wires are weakened for snapping off.

 

[JohnMo]

42 minutes ago, saveasteading said:

I did find a good one and worked to it. To your tips it adds using a hacksaw for the first sleeve cut, then the armour wires are weakened for snapping off.

 

You can also use an adjustable pipe cutter, this gives a nice straight score on the wires to then be snapped off - works better with larger cables (6mm² and above), not so good on small ones as they are too squishy.

[saveasteading]

28 minutes ago, JohnMo said:

adjustable pipe cutter,

Nice idea. But that was the easiest bit.

A really sharp knife helped too....must check I didn't do damage with it.

 

For connections inside the boxes I've used old-fashioned screwed terminal strips. 

Would modern lever connectors be better? I see some at screwfix are a fraction of the cost of the bigger name wago. I like the idea of getting second shots at it too, ie the lever releases.  The wago's I used once were push-in and perhaps fixed.

 

I'm thinking I will buy a better and bigger box today, and lever connectors.

 

[andyscotland]

56 minutes ago, saveasteading said:

For connections inside the boxes I've used old-fashioned screwed terminal strips. 

Would modern lever connectors be better? I see some at screwfix are a fraction of the cost of the bigger name wago. I like the idea of getting second shots at it too, ie the lever releases.  The wago's I used once were push-in and perhaps fixed.

 

I'm thinking I will buy a better and bigger box today, and lever connectors.

 

Old fashioned screw terminals have been around a long time and if properly installed are fine, there are millions of houses using them.

 

That said, I am a huge convert to Wago (lever-style) and similar connectors. They make it much easier to get a reliable long-term connection at the full current carrying capacity of the conductor, and eliminate a whole class of potential issues. And (unlike screw terminals, which can work loose over time) do not require future inspection/maintenance.

[Nickfromwales]

1 hour ago, saveasteading said:

Nice idea. But that was the easiest bit.

A really sharp knife helped too....must check I didn't do damage with it.

 

For connections inside the boxes I've used old-fashioned screwed terminal strips. 

Would modern lever connectors be better? I see some at screwfix are a fraction of the cost of the bigger name wago. I like the idea of getting second shots at it too, ie the lever releases.  The wago's I used once were push-in and perhaps fixed.

 

I'm thinking I will buy a better and bigger box today, and lever connectors.

 

Bigger box helps, as it’s just punishing to struggle with a smaller box with everything in such close proximity. Also gives you the option to add to it later without losing too much more hair. 

[Onoff]

A Bladerunner is what you want:

 

https://www.tlc-direct.co.uk/Products/KTWSBR28.html

[joth]

23 hours ago, andyscotland said:

I feel like at least black was neutral in the old UK colours so there's a kind of logic to that

Funny enough the last electrician that worked on my CU (in 2024) complained it must have been installed (in 2021) by someone old school as black was sleeved as blue, and the modern convention is to eschew black as neutral. I just smiled and nodded (perhaps with a shut up and do what you're here to do vibe)

 

[Nickfromwales]

On 23/07/2025 at 22:22, Onoff said:

I've got similar. I left brown as L, sleeved the black with blue for neutral and sleeved the grey with green/yellow for earth.

You'd be shot on sight mate. 

 

Black is earth these days, grey in neutral. I made the same mistake on a job and had my lead electrician losing sleep; I had to grant him permission to go around and undo my "mistakes" so he could stop from shaking.

[Onoff]

3 minutes ago, Nickfromwales said:

You'd be shot on sight mate. 

 

Black is earth these days, grey in neutral. I made the same mistake on a job and had my lead electrician losing sleep; I had to grant him permission to go around and undo my "mistakes" so he could stop from shaking.

 

Doesn't matter a carrot as long as you sleeve both ends as far as I'm aware. 

[Nickfromwales]

Just now, Onoff said:

 

Doesn't matter a carrot as long as you sleeve both ends as far as I'm aware. 

All the odd shorts-wearing NICEIC electricians (in obligatory overpriced VW Transporters with aftermarket alloy wheels) will hunt you down and make you eat those words. Quite strange standards with these lot, considering not one of them will pick up all the cable clippings etc after them. I guess living at home with mum places this type of thing well above them, but they do hate getting dirty tbf.