Capping off SWA

[Gone West]

Can anyone recommend a device that is weatherproof for safely capping a 6mm2 SWA cable. This is a temporary measure.

[Onoff]

I'd just gland it off (properly) in a weatherproof box and put the ends in connector blocks. I assume this is potentially live?

 

Better if you can screw the box to a wall etc.

 

Is where its going not there yet? Shed supply?

[pudding]

Thats what I've done and it's been sat there for over a year waiting for the next parts of my garden work. Not screwed to a wall though, just sat on the floor. No shorts or problems with it.

[Onoff]

Here you go:

 

http://www.screwfix.com/p/bg-nexus-4-pole-junction-box/33518

 

Or

 

https://www.toolstation.com/shop/p65903?mkwid=sRRETeyTP_dm&pcrid=189687010060&pkw=&pmt=&product=65903&gclid=CJ-N8dKL0dQCFa-_7QodAFgL0w

 

Both up to 10mm sq.

[Jeremy Harris]

I still have a run that's temporarily capped off, and all I did was leave the cable well over the required length (so I could cut it back), put some adhesive-lined heat shrink over the ends of the exposed cores (after stripping back armour and sheath a short distance) and squeezing the ends of the heat shrink when still hot to form seals over the cable ends.  A bit of bigger adhesive lined heat shrink over the whole lot, with a cut off bit of hot melt glue stick dropped down the end to finish it off, all melted with a hot air gun.  It's like a poor man's pot joint, and probably pretty robust and long lasting.  It's been poking up out of the ground for a couple of years now, and still seems OK.

Edited June 22, 2017 by JSHarris

[Onoff]

On the subject of SWA if doing a lot, or just 'cos it looks cool (and works), great tool this IMO:

 

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

[Jeremy Harris]

I started to make one of these, with an old pipe cutter and a bit of hacksaw blade a while ago, but never got around to finishing it.  I just machined up a bit of aluminium to fit where the cutting wheel of the pipe cutter goes, with a slot to take a short length of hacksaw blade.  I'll have to dig it out and finish it off, all it needs is a couple of small grub screws to hold the hacksaw blade bit in place.

[Gone West]

6 hours ago, Onoff said:

I'd just gland it off (properly) in a weatherproof box and put the ends in connector blocks. I assume this is potentially live?

 

Better if you can screw the box to a wall etc.

 

Is where its going not there yet? Shed supply?

I've got an IP66 box so I could do that. It would become live if switched on at the CU so it's for safety's sake. Eventually it will be the shed supply but will run under where the bungalow is at present. I was hoping there was something smaller that could just be clamped over the end of the cable. I quite like @JSHarris's idea of using heat shrink etc if it would pass muster with the electrician doing the Part P check.

[Jeremy Harris]

The electrician I used had no problem with the cable being capped off with the double insulated waterproof heat shrink end.  In essence it's no different to the way the immersed cable joint on our borehole pump is made; that has adhesive heatshrink over each conductor joint, plus another layer of adhesive heat shrink over the whole joint.

 

If you don't have adhesive lined heat shrink to hand, the non-adhesive stuff can be made into the adhesive stuff with hot melt glue reasonably easily.

[Gone West]

@Onoff & @JSHarris thanks for the ideas.

[Onoff]

Where exactly is this temporary joint going to sit?

 

Just heatshrink will provide no mechanical protection which is the whole point of the armoured and to a lesser extent "tough" PVC outer sheath.

 

As above not just me who likes a box. If you want "slimmer" but still tough as old boots you could use a resin joint on the end but block one end up before you pour (tape / foam).

 

http://www.screwfix.com/p/prysmian-puj10cc-resin-joint-10mm-4-core-max/43363

 

(Not sure if a Wiska Shark (gel), again v.slim and super quick to fit would work on just one cable).

[Jeremy Harris]

Good point.  The end of the cable I've terminated is poked back into a bit of duct that's sticking out of the a big lump of concrete foundation, so fairly well protected.  There's also a bit of marker tape tied around it as a bit of a warning that it may be live (if I was accidentally throw the DP RCBO on that circuit).  If it were buried without protection then the heat shrink cap may not be that good an idea.

[Onoff]

You could also get a lock off for the breaker if you wanted to go belt and braces...or take the breaker out for now and fit a blank.

[Onoff]

If it's going to live underground you could stick it in an alloy Pratley box. They're bulletproof. 'Kin expensive though! Would need to blank off unused entries of course.

 

https://www.tlc-direct.co.uk/Manufacturers/Pratley/Cable_Joints_1/index.html

[Mackers]

Cast resin joint. Cheap and impermeable.

[Onoff]

So that's 2 for a IP rated box on the end and 2 for a resin joint! Either would be my favourite. Trust you have some slack there as the resin joint will have to be cut off later.

[Nickfromwales]

Resin joint without a doubt. 

Also, I would never leave an unused / non-terminated supply connected to the breaker, that's just bad practice. If it's for any reasonable duration then you simply disconnect the live from the supply trip, bend it back on itself and zip tie it out of the way. 

 

[Jeremy Harris]

Using the sort of termination I suggested is effectively a pot joint, and is deemed OK for use submerged at depth down a borehole - it's what Grundfos supply with their pumps for just this purpose.

[Gone West]

9 hours ago, Onoff said:

If it's going to live underground you could stick it in an alloy Pratley box. They're bulletproof. 'Kin expensive though! Would need to blank off unused entries of course.

 

https://www.tlc-direct.co.uk/Manufacturers/Pratley/Cable_Joints_1/index.html

The box I've got spare is a Pratley, it's just a bit bulky. I think I'll go for the resin joint. I should have thought of @JSHarris's idea because I've got a bore hole pump with that type of cable connection, trouble is my brain refuses to work sometimes! Thanks again.

[Gone West]

As usual it's knowing what search string to use. I used 'adhesive lined heat shrink end caps' in the end.

http://www.ebay.co.uk/itm/Adhesive-Lined-Heat-Shrink-End-Caps-PLCE100A-Various-Sizes-/272706037889?var=&hash=item3f7e8be881:m:msC7GCZWMR0pdmmnOQ0pSqQ

 

Edited June 30, 2017 by PeterStarck

[Crofter]

Interesting thread.

On a related note, I was told that it's good practice to always twist together the wires of an open circuit, say if you're half way through a job and coming back the next day. So if it is accidentally energised, much safer to trip the breaker than to leave open live wires.

[ToughButterCup]

On 22/06/2017 at 23:02, Mackers said:

Cast resin joint. Cheap and impermeable.

 

You guys have forgotten how much you know..... 

 

Cast resin joint? How, what with? Do you smoke it?

[Gone West]

2 hours ago, recoveringacademic said:

Cast resin joint? How, what with? Do you smoke it?

Resin joint was my first search string. You can guess what Google came up with, until I put 'electrical' in front.

[Onoff]

Some of the dope fiends I've worked with would probably think those caps were lumps of Black Leb and try and shave bits off to smoke!

[Jeremy Harris]

5 hours ago, recoveringacademic said:

 

You guys have forgotten how much you know..... 

 

Cast resin joint? How, what with? Do you smoke it?

 

A colloquial term for them is pot joints............