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Armoured cable size for outbuilding


scotslad
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Alright folks just wondering wot size of armoured cable i'd need to run to an outbuilding/workshop?

 

Not any major heavy duty electical equipment althou i do have a welder but it always fine working of a 15amp plug (althou it would be nice to have a 30 amp socket for welding heavier metal if needed, but worried about the price and weight of the heavier cable that would be needed). Could be a couple of chest freezers etc running of it too.

 

The other thing its a fair bit away from the house and by the time i run it round the boundry and run it to dog kennel and back to boundry be looking at 200m+ of cable.

Is there much voltage drop on a run off cable that long?

Wot sort of weight would the cable reel be at that length? Would it be manageable be hand ball with no specialisd tools?

 

I

was hoping to put it's own power supply into it to save hassle and having a live cable buried underground, but looking to be to expensive. Has had powerin there in last 10 years and has the underground cable still in place (cut off below ground) and i cannae find the old MPAN number so are talking about a new cable being installed (25m) plus the fact the poles just in my neighbours garden no matter which direction i run the cable (25m all throu meighbours garden or 30m only 2 ft in neighbours garden) it will need a new Wayleave agreement which is about £700

 

Cheers

Edited by scotslad
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Various online calculators around mate if you look but given the length of cable / intended use, I would think you are looking at 6mm as a minimum.

 

Just googled some but from wot i could work out more for inside house wiring as wouldnae allow burying, and the 2 different other calculators had 16mm for 15 amps and 50mm for 40 amps over 250m.(and definately was no. . decimal places i missed)

Am i doing anything wrong/silly?

 

 

Aye cheers peter, i'm more woried about the distance but mibee its not that big a deal for voltage drop?

 

Just done some searching 6mm is 62amp, 10 is 85 amp and 16 is 110 amp but just worried with the distance and also the wieght of cable involved to be dragged throu tree/brush etc

So 6mm should do fine but when u have all the work of burying it etc u want to put the right cable in 1st time

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my mate is a sparks, he reckons 10mm to wire up my workshop, just in case I want to run a few tools etc at the same time, even just a transformer can draw up to 5kva and 32A. i'd want a 16A round socket for the welder too.

if you're worried about the weight then rig up a scaffold pole on some blocks so you can pull the cable off the drum easily.

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Cheers again tomov, putting a 40amp load and 250m it comes up 50mm2? Thats 2inch?? i was thinking 10mm or even 16mm for over kill

 

Thought i could prop the drum up like that somehow, but will still be a bit of weight/drag when ur pulling the 200m cable on the deck? Got a tirfor to pull if to heavy but was meaning to set it up so got a slightly downhill pull

 

Sort of hard to work out load but really just ur general run of mill workshop, generally just be myself working there so won't be 2 welders etc on at same time.

 

I take it u just add ammount of plugs likely to ever be on at same time to get load (ie chargers 3amp,freezers 3A,welder 15-30A etc) Possibly in time would like a lathe but i dinae think they draw a massive ampage (only be a hobby lathe)

Always wanted a proper 30amp welding plug in my dads gargae when i first got welder never ever got it done, prob been hobby weldiing/bodging for 15 years on normal plug circuits and never tripped/blew a fuse yet, and thhat is an arc welder. But more room here so i could get into bigger metal pieces

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It's an old outbuilding that is 1870's built in cracking stone (i think an old green/glass house/vinery or atleast the shed heating room behind it) and has a bit of a yard storage area, so is a cracking bit for working on projects/junk, so unfortunately moving it's not an option.

 

Its trying to run the cable round the boundry is adding heaps of distance but easier and probably better in long term than running a cable in a straight line.

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Not being funny mate , why don't you get a sparks in , with it being out side it is notifable special location , not saying you don't know wot ya doing but it's not just pulling a cable and ending of in sockets ,there is the protection of the ccts, earth ,connecting to the mains were how, testing signing of just don't want you to damage anything or anybody

Like I said not having a go

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No dinae worry i will be getting a sparky in to do the wiring work, althou i will do the donkey work trying to lay this cable and hand digg it in.

 

I'm only trying to get an idea wot size of cable i would need to price it aggainst putting a direct supply of the grid in there. Looking like i will need to pay this extra money for a wayleave agreement it probably be cheaper to run a cable. I'm dealing with Scottish Power the now trying to get a price for that and thought it would be a fairly straight forward question

Edited by scotslad
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Cheers again tomov, putting a 40amp load and 250m it comes up 50mm2? Thats 2inch?? i was thinking 10mm or even 16mm for over kill

 

Thought i could prop the drum up like that somehow, but will still be a bit of weight/drag when ur pulling the 200m cable on the deck? Got a tirfor to pull if to heavy but was meaning to set it up so got a slightly downhill pull

 

Sort of hard to work out load but really just ur general run of mill workshop, generally just be myself working there so won't be 2 welders etc on at same time.

 

I take it u just add ammount of plugs likely to ever be on at same time to get load (ie chargers 3amp,freezers 3A,welder 15-30A etc) Possibly in time would like a lathe but i dinae think they draw a massive ampage (only be a hobby lathe)

Always wanted a proper 30amp welding plug in my dads gargae when i first got welder never ever got it done, prob been hobby weldiing/bodging for 15 years on normal plug circuits and never tripped/blew a fuse yet, and thhat is an arc welder. But more room here so i could get into bigger metal pieces

That's not 2 inch a 50sq mm cable is around 10mm in diameter for each conducter

 

Deershooter

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250m is a long way.....have you considered a generator. You could then also have 3 phase which might give you better machinery options.

50mm2 cable is right for the load and distance, anything less and the volts drop when you switch anything on will dim the lights and if they are fluorescent they will go out totally and then come on again.

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That's not 2 inch a 50sq mm cable is around 10mm in diameter for each conducter

 

Deershooter

 

Cheers deershooter so sorry for such a daft question but 10mm per conductor is that the same as 10mm armoured cable?? Or if not wot size off armoured cable would i need to have 10mm conductors?

(as i do know its not 10mm outside dia, about the only thing i do know :oops: ) And do u only need the 2 conductors using the armour as earth or would i need 3 core (so 3x10mm conductors)

 

Gene is no good, have thought about it, but would have to constantly run to do freezers and or turn it on/off every time i need to put a light on the sheds or dog kennel. Plus there is a neighbour near the shed so not fair on them

Would imagine plenty of farms will have cable runs that long between sheds

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Your problem will stem from whats known as volts drop. There are calculations that need to be done first. Length of run, maximum loading, how the cable will be installed, ie underground, open air. A cable, in principle, acts like a water hose pipe, it doesn't matter what pressure/voltage your trying to put through it. If the cable is to small the volts will drop. If the hose is to small the water will only trickle out.

With electrics, the volts drop and the current rises. Most electrical devices will only work correctly within a small percentage either way of the said voltage. Bottom line is the longer the run and the higher the current needed the larger the cable needed to overcome this along with heat build up under normal loading. Don't forget the price for cable will rise accordingly. Dont expect it to be cheap.

I just put in 300m of 25mm squared 3core swa which cost arround £1800 cable only for a 16amp supply.

Edited by superspark
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Your two freezers and some lights are likely 'nothing', compared to driving a multi-kW welder. You need a sparky to advise you on what you could (or could not) run. Running high power kit through a 'too small section' cable could cost you dear if you burn out the compressor motors in your freezers. They don't like reduced voltages.

Edited by oliver90owner
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Cheers very much deershooter and super spark, that was exactly wot i was looking for

 

The building has had a power supply in past for prevoious owners and am looking into putting the supply back in direct (hence this question) but things are looking more complicated as pole is in my neighbours garden and despite there being an underground cable already in want to put a new underground cable and new legal wayleave agreement which is pushing the price up considerablely.

 

Generator just isnae really an option as would have to run it 24/7 365 to power chest freezers as well as the inconvenience of having to turn it on/off every time i need to turn a light on in shed or at the kennels am building probably halfway between the house and outbuilding so would have to walk way past kennels every time i want to turn a light on

Even to buy a generator big enough to power a welder is not cheap + the running costs and maintence, so even at £2500 for the cable would still be better than a genny

 

 

I've found a 2x50sqmm (to BS5467) for £6.76 inc Vat from Supalec Direct, but the problem is ur into almst 2T per Km so be looking at manhandling and dragging 1/2T of cable throu woods and over rough ground. While i'm sure its doable (even if i have to tirfor it) won't be much fun.

 

Cheers again fr the advice

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Sorry to resurect this thread again.

 

I was hoping to get a direct supply but now thats not looking possible, neighbours won't give permission to put a new cable in their garden (which i can ubderstand a wee bit as they're just putting house on market, but i won't be logging or splitting in more firewood for them now) and as pole is in there garden (althou only 2ft) to bring the cable the oppisate way and round boudry wouls require another wayleave agreement with a 3rd party, so looking at 1200-1400 quid in legal fees before any work done. Or come from another pole so an extra 50m of cable/trenching

 

Does anyone know any cheap suppliers of 50 sqmm armoured cable?

 

Or Is it possible to buy second hand/reclaimed cable?

 

Would imagine a temp power source like festivals etc might run long runs of cable. Or would some scrappy's sell it, even if not 1 long run, could afford a few joints (30-50 quid) if ur saving a lot on cable Think scrap value is 70p a meter

I know most folk would prob advise aggainst secondhand cable but its probably going to be a semi temp supply (prob 10ish years) so was mening to leave it on the ground most of the route it would be at the foot of a fence throu mature forestry so no danger of anyone digging on top of it.

 

The lad that owns a holiday house down the road is in the electrical trade and was shocked at first when i mentioned 50mm cable as so big but when he ran it throu his computer was right enough for the length of run. and he says it's not as dodgy as it sounds running a cable on ground giving the site or even a 2nd hand cable

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Firstly, a second hand cable may be in the old colours and will not comply with the current wiring regulations.

Secondly, I would suggest a three core cable as relying on the swa for a earth return is not the best way to go about things. Either way it's going to be an expensive project.

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Strictly speaking it would not need signed off or anything, but at the same time i don't want to use dodgy or really ancient cable. Still want the job safe

 

Just thought/hoped there might be some suppliers/specailist scrappies that might deal with stuff out of factories as some could be fairly modern and reuseable

 

Was actually thinking about my options at work this avo, possibly rigging up some 12V lights of a battery system and solar/windmills and leisure battery alongside a geny may be an option and save starting the genny every time i need to loo for a tool, but even a decent genny to take a welder will be 1K plus and u still have running costs and maintence/brealdowns on top too.

A cable would still be the prefered option really.

 

Cheers

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