Industrial Radials in SWA

[spuff01]

Hello all,

Trained years ago, not done much for about a decade but I've been asked by a friend to add 5x double sockets into an industrial unit, my thinking is to use a radial 32A RCB, 4mm 3-core SWA cleated to the wall (moderate impact risk). Area is small, only about 2-3m from the distribution board and there is no need for any spurs etc. I don't have a bender etc any more so don't fancy metal conduit. Appliances are almost all (very) inductive so C-curve.

I did do 18th in 2020 but haven't got a book handy, sorry if this is an egg-sucking question but can't recall current regulations for running radials. Not something I've done for several years and I recall 'something' had changed. Used to be 20A/2.5/50m2 if I recall but I know thinking has changed(?).

Cheers,
Ben

 

[LeeH]

‘very’ inductive items may need type D. Obviously you need low enough impedance to achieve disconnections times when choosing the type.

Calculate it before installing or wing it and test which I’m sure it will be the latter.

Getting 2 4mm SWAs into the back of a metal clad sounds like fun but the domestic boys manage with twin and skin.

 

[pc1966]

32A radial of the sort of length in SWA clipped to wall, etc, is no problem but you ought to look up regs for actual rating, etc.

You will almost certainly need RCD protection so a RCBO would be needed, but you are unlikely to need it C-curve if for 13A sockets (unless more than one load switched at once) but check the manufacturer's information just in case.

 

[Dustydazzler]

Shame you don't have a pipe bender as this sort of job ( such a short run ) I would do in pipe and 4 mm singles

 

[Dustydazzler]

and to add you don't even need a threader anymore for such a job I use ConLok on jobs like this and love the stuff. makes it so much quicker just fix the box , pop the conduit in and wind up the little grub screw. bosh

 

[plugsandsparks]

2 X 4mm stranded into metal clad sockets from click is doable, its generally how i do radials in industrial settings (usually conduit and singles though)

 

[Dustydazzler]

I think pretty much every sparks now uses 4mm for industrial / commercial radials , 4mm in / out in a double socket no problem if cut and dressed neatly

 

[7029 dave]

and to add you don't even need a threader anymore for such a job I use ConLok on jobs like this and love the stuff. makes it so much quicker just fix the box , pop the conduit in and wind up the little grub screw. bosh

Is it like the old slip tube DD, didnt think this was used in the UK anymore, the Americans use that kind of conduit system.

 

[Dustydazzler]

Is it like the old slip tube DD, didnt think this was used in the UK anymore, the Americans use that kind of conduit system.

You use normal everyday galvl 20mm conduit with Conlok

Honestly its fantastic

 

[7029 dave]

You use normal everyday galvl 20mm conduit with Conlok

Honestly its fantastic

I like the flexibility of it yup very impressed

 

[spuff01]

Interesting stuff, thanks all.

I have done 4mm SWAx2 in to sockets before, but as rightly pointed out it's a bit of a squeeze, that said the installation allows me to just put couplers between the boxes so I could actually just use singles between the boxes which would make life easier.

Found my book, and all looks fine in 4mm, although the price of Crabtree Polestar RCBOs is quite something! I'm sure they didn't used to be quite 'that' expensive! Fortunately, I'm not buying the parts!

Of course, a 'B' will be fine as it's highly unlikely the loads will be simultaneously switched as @pc1966 correctly reminded me! That's what happens when you've not done anything for 10+ years!

Thanks again all,
Ben