Ask The Trades - Print Page

Ask The Trades
https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> Sockets for workshop https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1089121984 Message started by Lee_Elms on Jul 6^th, 2004, 2:53pm

Title: Sockets for workshop
Post by Lee_Elms on Jul 6^th, 2004, 2:53pm

I wish to install sockets 'flush' to the wall in my workshop / garage.

The inside wall is timber studding filled with insulation and covered with chipboard.

Am I allowed to use plastic 'plasterboard boxes' for mounting sockets etc. on chipboard ?

Title: Re: Sockets for workshop
Post by plugwash on Jul 6^th, 2004, 2:55pm

dryline boxes should be ok though you may need to buy longer screws

any cables in that wall should be between the insulation and the chipboard (not burried in the insulation) and should be derated

i can't remember the exact figures but im pretty sure you need to use 4mm for a ring in that situation

Title: Re: Sockets for workshop
Post by plugwash on Jul 6^th, 2004, 2:56pm

also if the insulation is polystyrene you MUST use conduit

soft pvc (cable) is adversely effected by polystyrene
ridgid upvc (conduit) is not

Title: Re: Sockets for workshop
Post by Lee_Elms on Jul 6^th, 2004, 3:04pm

Thanks for the speedy response !

The chipboard is only 12mm (thinner than plasterboard) so I guess I'll be OK with the screws supplied.

The insulation is Rockwool; I assume this is OK with PVC cable.

Title: Re: Sockets for workshop
Post by L.Spark on Jul 6^th, 2004, 3:09pm

Hey Lee, if it's possible running the cable in round or oval conduit will be a better outcome, you can run 2.5mm twin cable for a ring in this situation, further allowances would have to be made if you ran the cable directly in the wall, rather than just in conduit in a thermaly insulating wall.

Get some 20mm round conduit and run all cables in this if you can, then a 32A rated ring circuit would be acceptable �:)

Title: Re: Sockets for workshop
Post by woodsmith on Jul 6^th, 2004, 3:34pm

Lee, one other thing to consider is that, if the wiring is behind the chipboard, when you come to hang the multitude of tools etc. on the wall, you stand a good chance of hitting a wire.

I,ve fitted �metal clad sockets and 20mm conduit as L.Spark has already recommended. It's the best way of wiring for a workshop and will even allow some changes to be made in the future should you want to move things about.

Title: Re: Sockets for workshop
Post by The_Trician on Jul 6^th, 2004, 9:23pm

Easiest way to do this is to dispense with trying to 'hide' socket/accessory back boxs and surface mount everything instead - if it is a workshop, then it shouldn't really matter what can be seen.

I'd go for 2"X2" Galvanised trunking all the way round at or above head height, then drop out of this with either 20mm plastic or steel conduit to surface-mount metalclad accessories.

Dead easy, less fiddly, and you can chop and change things quite simply. Also, you can run single-insulated cables evrywhere, which is much cheaper than double-insulated stuff.

Also, it'll most likely last forever!

TT

Title: Re: Sockets for workshop
Post by rabbit_rabbit on Jul 6^th, 2004, 10:48pm

Agreed I would always fit metalclad in workshops if for no other reason than strength, plastic acccesories WILL get knocked about and suffer.

RR

Title: Re: Sockets for workshop
Post by plugwash on Jul 6^th, 2004, 11:02pm

doesn't mean you can't put metalclads on flush boxes

Title: Re: Sockets for workshop
Post by L.Spark on Jul 6^th, 2004, 11:27pm

The industrial style approach would suit best agreed trician, not sure Lee wants to start cutting steel trunking and threading steel conduit tho

Title: Re: Sockets for workshop
Post by Lectrician on Jul 7^th, 2004, 7:23pm

TT gets my vote, you should see my garage :-)

I love industrial, give me some 400x400mm galv trunking and some nice large cables to play with and I will be as happy as a...............umm?............not sure what!

Title: Re: Sockets for workshop
Post by scotspark on Jul 7^th, 2004, 10:09pm

think 400*400 would be a tad excessive for some sockets in a workshop lec!!

but a nice bit of 50*50 run round jus aove the workbench and sockets can be mounted on top jus a coupling as a spacer to allow for plugtop flex or directly underneath bushed straight int trunking

Title: Re: Sockets for workshop
Post by Lectrician on Jul 8^th, 2004, 4:34pm

Yea, i like 2x2 galv, with a galve coupler drop to a socket (below). Use the same trunk to tube up and over to the lights etc.

Bit OTT for a domestic garage maybe??

used 400x400 last year on a job, havn't since used it :-(

Title: Re: Sockets for workshop
Post by L.Spark on Jul 8^th, 2004, 10:07pm

you really do love it lectrican, maby u can advise me on some flange adapter thing for some 4x4 trunking, need to spread cables :-/

Title: Re: Sockets for workshop
Post by Lectrician on Jul 9^th, 2004, 7:55am

to increase trunk from one size to another?? or teeing a smaller size from a large size??

Title: Re: Sockets for workshop
Post by L.Spark on Jul 9^th, 2004, 3:29pm

well i have to run some 4x4 to distribuition board, but want to segregate cables into several entry's along top of board (20mm K/O's), some one wrekones you can get some kind of adaption flange thing, il have to check it out ??? ::)

Title: Re: Sockets for workshop
Post by Lectrician on Jul 9^th, 2004, 3:35pm

2" galv couplers and bushes are best for larg DB boards.

If the board has a removeable top gland plate, this can be removed, and the exact same size hole jigged out in the trunking, use grommet strip where they meet, or better still, a piece of paxoline sandwiched between the two, with the hole in the paxoline cut about 10mm smaller all the way around.

Title: Re: Sockets for workshop
Post by L.Spark on Jul 9^th, 2004, 3:37pm

Well this trunking runs verticle from a suspended celing space, so it comes down right on top of the board, and couplers and bush will be weird like that, unless i run it down and then into a corner and couple from the horizontal peiece of trunking.

Title: Re: Sockets for workshop
Post by tellondon on Jul 9^th, 2004, 3:52pm

Run it down the wall then tee into a horizontal piece across the top of the board, then as Lectrician says either use 2" bushes with either couplers or lock rings or cut a oval slot out with paxoline sandwiched in between the trunking and the top of the board

Title: Re: Sockets for workshop
Post by L.Spark on Jul 9^th, 2004, 3:57pm

yep sounds about right, just sure ive seen T-Joints that fit onto trunking to alow the cables to spread at the board. thanks guys :P

Title: Re: Sockets for workshop
Post by tellondon on Jul 9^th, 2004, 3:59pm

Yep you can get tee joints with a flange so you can spread the cable out into the horizontal trunking

Title: Re: Sockets for workshop
Post by L.Spark on Jul 9^th, 2004, 4:02pm

sweet ;D

Title: Re: Sockets for workshop
Post by Lectrician on Jul 9^th, 2004, 8:35pm

Yea, Tee in to a horizontal length, or right angle it to a horixontal length.

You can buy the bends, or fabricate them using pop rivets. (best to ensure if you fabricate, that the trunking has one side continuous, eg, uncut. This ensures continuity).

If you buy bends, ensure you use atleast one earth link across the join, the trunking manufacturers make links to fit where theie screw holes are.

Paxoline is hard to get nowadays, and couplers with 2 bushes are a better job.

Dont forget to supp bond the trunking from the fuseboard :-)

And use round head screws to fix the trunking home, not counter sunk :-)

And, not many people seem to realise, if you cut the trunking lid, and the cut comes in a bad place, leaving the trunking lid buckles to far from the end.....you can get additional buckles that you can drill in :-)

Title: Re: Sockets for workshop
Post by The_Trician on Jul 9^th, 2004, 9:12pm

Flanges? We used to call em bellmouths - just cut a big slot in the top of the dist board with a jigsaw - 2" wide and however long the width of the top of the board will allow, then buy a 'bellmouth' or flange and bolt ot to the dist board top. Bring your trunking straight onto the bellmouth. if it's 2"x2" then you can get a bell mouth which starts at 2" and widens out to accomadate your cables. Just ensure that you maintain good continuity.

I always run a seperate earth in any case, regardless of whether its steel or plastic stuff.

TT

Title: Re: Sockets for workshop
Post by Lectrician on Jul 10^th, 2004, 9:08am

Dont know if they make bellmouth flanges anymore, I think you may have to take some metalwork classes :-)

Title: Re: Sockets for workshop
Post by L.Spark on Jul 10^th, 2004, 12:52pm

It's no problem, chap from CEF has found me one now, it's as trician described and same as what tell/lec said I think, secures into the dist board and then secures to a verticle section of trunking.

cheers