Brand of plug and metal or plastic conduit?

[Hsmith192]

Hi all- does anybody have a favourite brand for electrical metal sockets ?
and would you choose plastic or metal conduit in a garage workshop for woodwork?

Electrician is asking me and I’m not too sure what I should go with.

Thank you

 

[Spectric]

For a home workshop doing woodworking there is nothing wrong with using PVC conduit but don't scrimp on the saddles so it gets good support and does not sag. As for sockets there is not really much difference if you stay with the main brands, MK BG Sneider etc but again you do not really need metal clad but also nothing wrong in using them. I would suggest getting them wired as radials and for future proofing have the electrician put in a couple of 16 amp circuits.

 

[Phil Pascoe]

I've not wired up radials before - how many sockets can you put on one? I've a workshop/shed coming up and I would like to get some donkey work done before the sparky gets involved. I need loads of sockets - trailing leads and wheelchairs don't mix well. The actually loading on them though is minimal, I'll have the kilns on their own radials and saw and the welder on 16a supplies of their own.

 

[flying haggis]

you can have as many sockets as you want on a radial as the whole lot will be limited by the MCB size protecting it. so if you have twenty sockets each drawing 1A if you had a 20A mcb it wouldnt trip. ok silly scenario but you get the idea

 

[Spectric]

how many sockets can you put on one

With single phase you can run a 2.5mm radial from a 20 amp protective device or a 4.0mm radial from a 32 amp protective device.

you can have as many sockets as you want on a radial

but each radial is restricted to being within an area of 500 square foot.

Radials make life easier both with installation and any test and inspection work, the old historic ring main should be just that. It would be easy to run a circuit down each side of your workshop, when you reach the last socket that is it because you have no return to the board. Depending on how your workshop is constructed and it's layout the way I like to do this type of installation is to use box trunking and drop a pvc conduit down to each socket which makes the wiring easier. You also have have got future proofing built in because it is easy to add later. Remember the protective device in the board is only there to protect the fixed wiring for short circuits, to trip a type B protective device rated at 32 amps will need a short circuit current of around 160 amps to trip within the stated disconnection time.

 

[powertools]

I think that if I were paying an electrician to do a job like that for me I would expect him to talk through the options with me.

 

[Phil Pascoe]

Certainly. I was only getting my thoughts in order. I have someone lined up to do the work, but may well put the socket circuits in first. It's unlikely there will be a kW of loading anywhere on these radials, everything over that will be on its own supply. Two kilns, compressor, welder ...

 

[Sideways]

20mm and 25mm plastic conduit and fittings are commonly available in black or white at screwfix, toolstation, city electrical, and all the electrical wholesalers.
Personally for a home woodwork shop that's what I would and did use.

For an industrial or commercial shop I would be more inclined towards galvanised steel tubing for the drops as they give more protection when someone clobbers them with an 8x4.

An interesting new option is MT supertube from Marshall Tufflex. This is a composite tubular conduit plastic outer, aluminium inner.

As for the metal boxes, MK are very nice but expensive like everything MK, so for the workshop I just buy screwfix own brand as it's good value.

If you have a lot of cabling running across one wall, a method is to fit generously sized trunking along the top of the wall and drop round conduit down from this to sockets or groups of sockets as needed. Cheap plastic trunking is soooo nasty because it lacks strength and the capping peels off very easily. If you use a better quality double wall dado trunking like the Schneider Mita 100x50mm stuff, it is very much more robust and makes for a nice installation.

 

[trvlr]

Black pvc conduit doesn't show the dirt as much as white. Metalclad boxes and sockets/switches etc. are better in a workshop. Also you'll need a few pvc conduit boxes (with covers) to enable/faciltate puling cables around bends/corners (i.e. need to make 90 turn - use a conduit box ). You can't pull a cable around two 90 bends easily - and certainly not advised. Also on long run useful to have pass through conduit boxes to again facilitate cable pulling over long lengths. Remember to use adequate saddle clips for ease of instalation/fixing conduit to walls.

Flexible conduit also has its uses too in some situations.

And you can't beat a set of cable rods to make it all a lot easier.

I wired up my garage/strorage (potential work space) usng single cores... So much easier than pulling twin and earch.

MK metal clad are expensive; but SCRWFX have other brands too which are equally OK. I often prefer Crabtree stuff too.

If the pennies allow use sockets/switches with neon indicators too; but that's not essential.

 

[Hsmith192]

Thank you everyone. Really appreciate it!

 

[Heluvaname]

I'm a bit late to this, but in case it's still of help, I would:

Run a length of 50x50 metal trunking around all the walls, ideally at say 1200mm above the floor (or if that's not practical then at eaves level, but you'll use more conduit).

If at 1200 you can then mount metalclad sockets directly above or below the trunking using a threaded coupler and two bushes. If at eaves then drop down to the sockets with heavy duty 20mm plastic conduit (not the really cheap DIY stuff).

I'd still use metalclad sockets as they're harder to break. BG are fine and reasonably priced. Always put in more sockets in than you need!

If you want to include emergency stop buttons (good idea for bandsaws, lathes, etc) they can couple directly to the trunking if at 1200, and to one side of the machine.

If you want, you could feed all the sockets from a contactor and have a master Red button by the door to kill everything when you leave. Bear in mind you may want a "24hr" circuit for battery chargers, fridge, alarm, etc so you may want to wire a separate circuit for those.

Also lighting circuits can be run in the same 50x50 with rises to the light fittings on the ceiling and light switches coupled directly to the trunking again.

If you've got a big space or a central bench then fit a couple of sockets on the ceiling or beam above the bench so you don't have trailing leads across the floor to it.

 

[Chief Sawdust Maker]

50mm x 50mm grey plastic trunking at ceiling level
Drop down with 20mm black plastic conduit, use black metal saddles to conform to latest regs
Metal clad sockets MK are good
I have sockets at bench height some just below the trunking and some at floor level
Put in as many as you can afford its great not to have to keep plugging and unplugging stuff I also have a number of groups of sockets controlled by a 20amp DP switch so as for example your charging station can be isolated on one switch also my compressor is buried under a bench pluged into a low level socket but controlled by an isolator above the bench
Some of my machines require a 16amp supply they are wired individually with an adjacent isolator.
A couple of sockets mounted to the ceiling have been really useful mine are controlled by a separate switch and are used to power the workshop sound system and the air filter and a couple above the bench for when using routers etc it saves tripping over cables.
I also have a number of sockets on a separate ring that i only plug "clean" items into such as laptop, phone charger, printer etc so no danger of a surge from any power tools or small machines.
Remember power sockets are like clamps you will never have enough lol

 

[yngndrw]

I'd add that I would run multiple radials, interleaving the sockets so that adjacent sockets are on different circuits. I'd also run trucking at ceiling level with conduit down and singles inside, or possibly a high-level cable tray with Tuff Sheath drops to the sockets. I'd include a dedicated circuit for anything that you intend to use a lot, such as a dust extractor or air compressor - As these will be used in conjunction with other tools.

I also like the idea above of being able to isolate all tools from a single location, that way you can ensure that nothing is left on or accidentally started by inquisitive hands. You can use contactors to allow a single (lockable) switch to control multiple circuits and this can also tie in to a workshop-wide emergency stop. (But make sure you don't cut off the lights with that!)

 

[Stuart Moffat]

If possible, I’d recommend using RCBOs (as opposed to the cheaper option of a bunch of MCBs clustered through one or two RCDs. The RCBOs cover both functions, and the price is reasonable these days and they can also be as compact as an MCB (e.g. from Hager). A big benefit in a workshop is that it should mean you don’t find yourself in the dark with broken and flailing bandsaw blade. This scenario happened to me. I’m not sure of the exact sequence of events but the motor on the Record bandsaw failed and tripped the RCD and the blade snapped more or less concurrently. It was after dark. It was scary! To make sure you avoid similar using RCBOs ask the electrician to check what RCDs may be in the chain before it gets to your workshop and deal with that appropriately.
Stuart

 

[yngndrw]

If possible, I’d recommend using RCBOs (as opposed to the cheaper option of a bunch of MCBs clustered through one or two RCDs. The RCBOs cover both functions, and the price is reasonable these days and they can also be as compact as an MCB (e.g. from Hager). A big benefit in a workshop is that it should mean you don’t find yourself in the dark with broken and flailing bandsaw blade. This scenario happened to me. I’m not sure of the exact sequence of events but the motor on the Record bandsaw failed and tripped the RCD and the blade snapped more or less concurrently. It was after dark. It was scary! To make sure you avoid similar using RCBOs ask the electrician to check what RCDs may be in the chain before it gets to your workshop and deal with that appropriately.
Stuart

This is a very good point, adding emergency lighting would not be a bad shout.

 

[Skeety]

Hi,

Bit late to this but I had the same question about the sockets. I'm going for metal clad and had planned to use MK, local wholesaler recommended Hamilton so I bought one to compare. The metal is a little thinner but not enough to be of concern and the quality was pretty similar. The thing that swung it was the price, at £15 for a Twin socket in MK land vs £5 for the same in Hamilton. If it were a few sockets I wouldn't bother but the savings when you are fitting nearly 20 is huge. Their grid system is also nice and they do the euro modules which will match but also be a significant saving.

Going to put the savings into RCBO's instead of RCD's

Have a 14 way Verso consumer unit ready to go, again, recommended by the Wholesaler and backed up by my own research. Only 12 ways usable but the board does include an SPD.

I still have the Black\white conduit quandry. Going to use 25mm for ease of install and a higher power factor than 20mm when it comes to bends.