SWA Glands : Poor Fit

[kenburgess]

Background:

Served my apprenticeship 1964 to 1969 with NORWEB but not been directly employed in the industry since then.

I have just laid a 10mm 3 core SWA cable in a trench under the patio from the house to a detached garage 8.5m away. (cable run will be around 18m to 20m).

There won’t be much load in the garage other than lighting, sockets and an electrically operated door and possibly a router but I am making provision for a 7.2Kw Electric Vehicle Charging point, which will be a further 10m run to far corner of the garage from the garage consumer unit. I may also install more Solar panels on the garage so the supply to the garage may also at some point be a feed to the house. Battery Storage is also a consideration. There is no water feed or metal parts to the structure. Single brick construction, wooden roof beams and tiles.

My question is: As far as I can determine, there are two types of gland for use on SWA cable: indoor and outdoor.
For a belt and braces approach I’ve chosen the outdoor type even though both ends will be indoors. The recommended gland for 10mm cable is Niglon 25CW.
This gland has a compressible rubber/neoprene ring which provides the higher IP rating. However from the pictures you will see that it will never compress sufficiently to make a seal on the cable sheathing.

OD of Cable 18.9 (measured 17mm). ID of Compression ring 24mm.

I realise these glands are for a variety of cable sizes but the next smaller gland isn’t big enough for the 10mm cable and this one seems far too big.

Do I have to apply large amounts of tape around the cable sheath for the gland to compress? Or am I missing a trick?

I also have 1.5mm and 2.5mm SWA for sockets in various places around the rear garden for shrub lighting and an ultrasonic cat repeller. I currently have the internal glands (Niglon 20BW) which is a mistake as most of these will be used external. However these glands also seem too large also and I’m sure the external version will have the same problem compressing onto the sheath. I’m sure the shroud isn’t sufficient protection for an IP66 rating.

2nd Question: to conform to the new colour coding I need to sleeve the cores in Blue and green/yellow.

I have 5mm Green/yellow sleeving which will just about push onto a short piece of core but would take forever to do a long piece. I need some 6mm sleeving which doesn’t seem to be available from my normal sources.

Any suggestions?

Any advise welcome.

Ken

“The difference between genius and stupidity is, genius has its limits.”

 

[kenburgess]

OP? Person of a certain age.

Thanks for all the help with the SWA gland sizing charts, much appreciated.
I took the recommendation on the TLC webpage: 10.0mm² 6943X 3 core SWA Steel Armoured Cable - https://www.tlc-direct.co.uk/Products/SW10slash3.html
Thought they would know the correct one for the cable. Apparently not.

Although using the 20CW it is quite difficult to get the nut to tighten on the armour. probably on the limit of the cable size it will accept.

“To the optimist, the glass is half full, to the pessimist, the glass is half empty. To the engineer, the glass is twice as big as it needs to be.”

 

[snowhead]

OP? Person of a certain age.

Original Poster extra words to comply

 

[Risteard]

OP? Person of a certain age.

Thanks for all the help with the SWA gland sizing charts, much appreciated.
I took the recommendation on the TLC webpage: 10.0mm² 6943X 3 core SWA Steel Armoured Cable - https://www.tlc-direct.co.uk/Products/SW10slash3.html
Thought they would know the correct one for the cable. Apparently not.

Although using the 20CW it is quite difficult to get the nut to tighten on the armour. probably on the limit of the cable size it will accept.

“To the optimist, the glass is half full, to the pessimist, the glass is half empty. To the engineer, the glass is twice as big as it needs to be.”

The problem is that 3 * 10mm^2 is on the edge of the two sizes, and therefore different manufacturers advise different sizes. Some even list it as 20/25. But 20mm seems to be recommended more frequently than 25mm.

 

[kenburgess]

By the by, have you read up on the issues of ev charging, with pme supplies (if that’s what you have). Couple of threads on here about it.

Can't lay my hands on it at the moment but I had a guide from the IET regarding EV charging. I seem to remember the earthing arrangements seemed to be extensive to say the least. When I get some spare time I'll search for the threads.

 

[telectrix]

check and see if your 20 gland is CW20S. if so, try a CW20L.

 

[ipf]

check and see if your 20 gland is CW20S. if so, try a CW20L.

Come on tel...he wouldn't have had the slightest chance with 20S and a 10mm 3 core......they're right for the smaller cables, though.
OP. The CW are a struggle, sometimes, but they'll go.
Most cable used tends to be 90 degree rated these days, hence the smaller diameter. Getting the right size cleats can be a pain, too, with some.

 

[kenburgess]

I've ordered some of each from screwfix so I can try them out before ordering the full amount. Should be able to pick them up tomorrow so will let you know how I get on.

 

[Pete999]

Background:

Served my apprenticeship 1964 to 1969 with NORWEB but not been directly employed in the industry since then.

I have just laid a 10mm 3 core SWA cable in a trench under the patio from the house to a detached garage 8.5m away. (cable run will be around 18m to 20m).

There won’t be much load in the garage other than lighting, sockets and an electrically operated door and possibly a router but I am making provision for a 7.2Kw Electric Vehicle Charging point, which will be a further 10m run to far corner of the garage from the garage consumer unit. I may also install more Solar panels on the garage so the supply to the garage may also at some point be a feed to the house. Battery Storage is also a consideration. There is no water feed or metal parts to the structure. Single brick construction, wooden roof beams and tiles.

My question is: As far as I can determine, there are two types of gland for use on SWA cable: indoor and outdoor.
For a belt and braces approach I’ve chosen the outdoor type even though both ends will be indoors. The recommended gland for 10mm cable is Niglon 25CW.
This gland has a compressible rubber/neoprene ring which provides the higher IP rating. However from the pictures you will see that it will never compress sufficiently to make a seal on the cable sheathing.

OD of Cable 18.9 (measured 17mm). ID of Compression ring 24mm.

I realise these glands are for a variety of cable sizes but the next smaller gland isn’t big enough for the 10mm cable and this one seems far too big.

Do I have to apply large amounts of tape around the cable sheath for the gland to compress? Or am I missing a trick?

I also have 1.5mm and 2.5mm SWA for sockets in various places around the rear garden for shrub lighting and an ultrasonic cat repeller. I currently have the internal glands (Niglon 20BW) which is a mistake as most of these will be used external. However these glands also seem too large also and I’m sure the external version will have the same problem compressing onto the sheath. I’m sure the shroud isn’t sufficient protection for an IP66 rating.

2nd Question: to conform to the new colour coding I need to sleeve the cores in Blue and green/yellow.

I have 5mm Green/yellow sleeving which will just about push onto a short piece of core but would take forever to do a long piece. I need some 6mm sleeving which doesn’t seem to be available from my normal sources.

Any suggestions?

Any advise welcome.

Ken

“The difference between genius and stupidity is, genius has its limits.”

View attachment 52206 View attachment 52207 View attachment 52208 View attachment 52209

You need to use the correct gland for the size of cable, adding tape to make it fit is Amateurish, and you should sleeve the core appropriately to the situation and adhere to the new harmonised colours as dictated in BS 7671

 

[HappyHippyDad]

I've ordered some of each from screwfix so I can try them out before ordering the full amount. Should be able to pick them up tomorrow so will let you know how I get on.

I have just had the same problem. I rarely use 10mm 3core SWA but I did recently. Many charts show as CW25 being needed for 10mm 3 core so this is what I tried. it was far too big (It did say CW25L on it but i didn't think there was a large variety of the 25?). I then used a CW20 (not a CW20s, that would be far too small). The CW20 is a tight fit but it does work.

 

[Bellendian]

For reasons that I don't fully understand, for 10mm 3core especially, cw20l works nicely, but bw20l is very tight.
Found a similar scenario with 6mm, between 20l and 20s, but seems more variable depending on cable supplier.
It seems that cw glands often have the conical slip ring to clamp the armour, while bw just have the nut and the knurled part on the gland body. I think this allows a smaller cw type gland to better accomodate the armour, and the ip nut to clamp the sheath. On a bw, within reason, it matters not if it's too large, armour still gets clamped.
In any event, choose the gland that fits the cable you have, as opposed to what the table says.

 

[ipf]

It seems that cw glands often have the conical slip ring to clamp the armour, while bw just have the nut and the knurled part on the gland body. I think this allows a smaller cw type gland to better accomodate the armour, and the ip nut to clamp the sheath. On a bw, within reason, it matters not if it's too large, armour still gets clamped.

Never heard that one before. It's all about the manufacturer and different design.

 

[Bellendian]

Just an observation. Glands I get are from same manf. Cw's have the smooth cone and slip ring plus nut, bw's the knurled cone and just a nut. Cw's more accomodating, in my opinion.

 

[Midwest]

Can't lay my hands on it at the moment but I had a guide from the IET regarding EV charging. I seem to remember the earthing arrangements seemed to be extensive to say the least. When I get some spare time I'll search for the threads.

The issue is with pme, and then converting the ev supply to TT; with the car being charged outdoors.

There are some units that use option iii) in the regs.

Few threads on here.

Do EV chargers need earth rods

Electric vehicle charge point manufacturers are adding intelligent electronics to remove the need for earth rods.

www.efixx.co.uk

On another matter, as this appears it’s going to be a new circuit, have you resolved notification to your LBC?