View Full Version : shed/garage electronics,

15-07-2013, 09:50 PM
So, my shed has a power line running out to it that is wired from a socket in our conservatory. I'm not sure how above board it is :l

when I turn my lathe or steppers on the lights blink.

I'm thinking that I might need some better/thicker cabling? or for it not to be daisy chain from an extension?

any ideas?


15-07-2013, 10:11 PM
Really Depends on what amps your pulling but working from an extension isn't good idea in any case.!! Your just asking to burn the place down and by that I mean the house not the Shed.:dejection:
On top of this Insurance will just laugh and give you the finger when found using extension or any kind of dodgy wiring.!

Really you want it on it's own circuit with it's own fuse and using appropriate sized wire for the amount of draw. Anything less is just not worth the risk IMO.

15-07-2013, 10:59 PM
okey dokey, I'll get in touch with a professional

Clive S
15-07-2013, 11:10 PM
I think that you will find that you will need to have an isolator in the house and a consumer unit in the shed and the cable will need protecting with an rcd I would use wire armoured cable between to two. ...Clive

Robin Hewitt
15-07-2013, 11:43 PM
The lights will blink if they are on the same circuit, lighting is usually on a separate circuit so as not to worry you.

15-07-2013, 11:49 PM
Taking electricity outside - DIYWiki (http://wiki.diyfaq.org.uk/index.php?title=Taking_electricity_outside)

Web Goblin
20-07-2013, 11:56 AM
Get a pro in for this one as there is much more to it than running in a bit of cable, length of run, load required, volt drop cable type, earthing and supply type. For some domestic supplies ( TNCS I think) its not recommended to extend them outside of the house so alot of the time a phase and neutral is ran from the house BD to the shed DB and them the installation is them earthed via a TT system at the shed.
So short story get a decent spark.

24-07-2013, 10:18 PM
Could you post the quote for a pro to do the work if you get one. I am after the same and had a quote for it but think its a little pricey...
Rcd, 60ft of armoured cable, 4 double sockets and flo tube - 480.

Web Goblin
25-07-2013, 06:09 AM
Without knowing exactly what is getting fitted and seeing the job it might be a good price. I take it that the spark will run in the cable, drill through any walls in the way, fit distribution board in the shed, connect up cable in house and fit rcd, fit all sockets and lights in shed and wire them. Fully test installation and provide you with test cetificates. How is cable being run from house to shed? Digging trench? All in a good days work so price might be ok.

25-07-2013, 08:21 AM
I agree, there's at least 80 of parts at trade prices, then factor in labour costs at 35+ an hour and running 60ft of cable especially if trenches is a good days work, possibly 2 if he's a one man operation.

29-07-2013, 01:55 AM
So back to my original question, my new machine running 4.2a 50v steppers and a 3kw spindle I'll be drawing somewhere in the range of 5-6 thousand watts.
even a basic consumer unit will cover those needs easily.

what do you mean by having an isolator in the house? do you mean one line straight from the house's RCD to its own MCB in then going to the shed?

I'm probably not going to attempt it and see if my family are owed any favors, I just want to learn a bit more :)

29-07-2013, 07:21 AM
At 6kW you'll almost certainly need a separate circuit and isolation switch off the meter (unless you have a recent 17th reg consumer unit with a spare unprotected way) and a secondary split load distribution unit with 2 rcd and separate power & lighting circuits in the shed as you certainly don't want to lose the shed lighting if the power circuit trips. You'll need 4mm SWA cable as 2.5mm is marginal on voltage drop.

29-07-2013, 10:52 AM
.. 4.2a 50v steppers and a 3kw spindle I'll be drawing somewhere in the range of 5-6 thousand watts.......I just want to learn a bit more :)

4.2A @ 50V is 210Watts

X 3 = 630w

It`s 630W at 50V or 250V , for calculation and allowing power supply losses call it a 1 kilowatt plus your 3 Kw spindle sounds like your allowing 1-2kW for lighting...

if you want to learn a bit more , read the link previously provided.

BUT if you are unsure about calculating loads , exporting power outdoors is considerably more involved and will be best left to someone comfortable with calculating things like earth impedance and disconnect time.