Astro_Al Posted March 10, 2009 Share Posted March 10, 2009 Howdy, more workshop rubbish I'm afraid. I need to extend my 3 phase socket arrangement so that I can leave a number of tools plugged in. I currently have 2 x 16A outlets and 1 x 32A outlet on the wall in question. I'd like to mount some extra outlets like this on the wall (maybe, say 5 or 10): I'd wire them all into a 'box' with one intlet with a wire & plug to the existing wall mounted socket, like this: the existing switched wall sockets are shown in red. Obviously I've done a circuit for 16A and one for 32, but the principle is the same for both. Plus I'll add a 63A circuit soon. My question is - how do I make the 'box' between the plug (to existing socket) and all the little wall-mounted sockets? I guess just a plastic housing of some sort with 5 bus bars in? Any inputs on the design so I don't kill myself? I'd just add extra sockets, but the distribution board is full, and it costs the earth. This will be far cheaper, and is basically a glorified extension lead. Obviously I only expect to run one tool at once, so max current issues are not really a concern. Cheers, Al. P.S. - who can tell me why it goes 16A, 32A then 63A (not 64)??? I have a feeling I asked this before somewhere, but its gone again... Quote Link to comment Share on other sites More sharing options...
Mark Posted March 10, 2009 Share Posted March 10, 2009 Al, why not daisy chain from one socket to the next one? There should be room in the terminals on the back of the socket to get the cables in. That way you can just use an off the shelf junction box where your box is (I think I used a 6-pole 30A rated one for a similar application). What size cable are you using? NB if any sparkies read this, I didn't do it, it wasn't me.... Mark Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted March 10, 2009 Share Posted March 10, 2009 What size wiring do you have on the current sockets? Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted March 10, 2009 Author Share Posted March 10, 2009 Hi Mark, thanks thats not a bad idea and will cut down on cable costs significantly - dunno why I thought they'd all need their own cable really?! I'll be using the flexible / semi-shielded stuff i think its type H07, as its pretty cheap & convenient from CEF or wherever. Regarding sizes, I wish I could find a chart of sq mm to amps rating (I know it depends on run length etc, there must be a graph or something somewhere). For 16A I normally use 2.5 or 4 mm - I've been told thats enough(??), not sure what to use for 32A, and even less sure about 63A stuff. It starts getting very fat. I'm not sure I could daisy chain the 32A stuff, let alone the 63s. Cheers, Al. Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted March 10, 2009 Author Share Posted March 10, 2009 What size wiring do you have on the current sockets? Hi Luke - not sure, it was all done professionally and is hidden in trunking. they used individual 'wires' not 5 core cable, and wired each terminal of each plug directly all the way to the dist board. Cheers, Al. Quote Link to comment Share on other sites More sharing options...
Mark Posted March 10, 2009 Share Posted March 10, 2009 16A should be fine with 2.5mm and for 32A I would go up to 4mm. This is completely on the proviso that you will only be working with one socket at a time. If you were planning to run more than one thing off your 'extension lead' at close to current capacity then none of what I have said holds true! Personally, in my own space, I know I am going to be the only one working there (possibly one other) so the possibility of using more than one socket at a time is very low. Multiple sockets just allow you to leave machines plugged in and/or convienence for having the socket where you need it. I guess if you are planning to run a busniess out of this building then something somewhat more official would be required.... Mark Quote Link to comment Share on other sites More sharing options...
steve_d Posted March 10, 2009 Share Posted March 10, 2009 How about one of these to make your enclosure on the end of the extension. http://essentialsupplies.co.uk/acatalog/enclosures.html http://essentialsupplies.co.uk/acatalog/ENC3.jpg Steve Quote Link to comment Share on other sites More sharing options...
J@mes Posted March 10, 2009 Share Posted March 10, 2009 The relationship between cable size and current has many different factors with it - type of cable, number of cores, number of circuits in the trunking - all this information is in the Big Red Book - the 17th Edition Regulations. you want 4mm for up to 34Amps use ( multicore thermoplastic insulated and sheathed non-armoured cables) which is "free in air" (ie its not enclosed or clipped to a wall.) Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted March 10, 2009 Share Posted March 10, 2009 This is completely on the proviso that you will only be working with one socket at a time. If you were planning to run more than one thing off your 'extension lead' at close to current capacity then none of what I have said holds true! That's why I was asking about the actual wire size used on the existing set up. you may have some head room with the existing wiring to add more sockets. you may not. Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted March 10, 2009 Author Share Posted March 10, 2009 Thanks guys, the idea is purely so I can leave machines plugged in and not be forever plugging stuff in / farting about with cables. Its only me, and I'll only be using one thing at a time. I think thats the way forward, the only issue is whether I can get 2 cables into 1 socket for the series wiring. Cheers, Al. Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted March 10, 2009 Share Posted March 10, 2009 the series wiring. Parallel! Quote Link to comment Share on other sites More sharing options...
ChrisW70 Posted March 10, 2009 Share Posted March 10, 2009 Do they need to be positioned around the workshop or could, say, the 16A sockets be mounted on a wooden back board, likewise the 32A? From a regs point of view, should you have the need or requirement to get a periodic inspection done at any point in the future, if the sockets were on a backboard with a flying lead to plug into an existing socket then at least you can unplug the 'non-conforming arrangement' and hide it in a cupboard sort of thing. Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted March 11, 2009 Author Share Posted March 11, 2009 Parallel! True, electrically, but in terms of the actual layout / cable its 'kind of' series, which is what I meant... (if you see what I mean) Chris, good point, but I need quite a few over, say a 15m length. I'll just bung them on the walls and cross my fingers. Its only me working in there. Al Quote Link to comment Share on other sites More sharing options...
Paul Wightman Posted March 11, 2009 Share Posted March 11, 2009 Do they need to be positioned around the workshop or could, say, the 16A sockets be mounted on a wooden back board, likewise the 32A?From a regs point of view, should you have the need or requirement to get a periodic inspection done at any point in the future, if the sockets were on a backboard with a flying lead to plug into an existing socket then at least you can unplug the 'non-conforming arrangement' and hide it in a cupboard sort of thing. As Chris says, if you want to do something dodgy with electrics it's best to make it 'hideable' so as to avoid embarrassment when visited by an expert! So long as you use the correct size and type of cable, each outlet has an isolator and correct fusing is applied you will probably live Why not have a ring main or more correctly for individual machines a fused, isolated supply from your distribution board? Once again, is this the best place to ask? Quote Link to comment Share on other sites More sharing options...
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