240v Extension lead, How long can you go

[rijidij]

I'll be building a shed about 120m from my house soon, and there's no power point at that end of the property. I need to get power there just while I'm building the shed, it will be wired up at a later date.
I realise it's a long way to run a lead and there are limits to what you can draw through it, but what could it handle if it was at least a 15a rated lead.
The biggest piece of equipment I will probably need is my 15a air compressor, although I do have a smaller 10a compressor I could get away with.
Other than that it will just be power tools or battery chargers.

Will a long lead be ok, or would it be better to go with a generator.

Thanks for any advice.

Cheers, Murray

[bee utey]

For the daily stuff, solar panels, a deep cycle battery bank and an inverter. For the big stuff a generator. You could also rig a petrol powered compressor for the big jobs, coupled with an alternator to top off the battery in overcast weather. Or just do the underground trench and get a decent cable (16mm2) to the shed permanently.

[rijidij]

For the daily stuff, solar panels, a deep cycle battery bank and an inverter. For the big stuff a generator. You could also rig a petrol powered compressor for the big jobs, coupled with an alternator to top off the battery in overcast weather. Or just do the underground trench and get a decent cable (16mm2) to the shed permanently.

Thanks, I should've been clearer, it's just for the building of the shed that I need power, I've edited my post.

Cheers, Murray

[Tombie]

I would run the power feed first, then build the shed...
You can fit a stand alone JB/Distro board at the shed site and plug into that.

Just changing the order around [emoji6]

[incisor]

i run 6 @ cheapy 10amp 30m leads from bunnings from my builders power pole 170m up to the shed at wattlemere and have run a 10amp compressor for a short time without difficulty. leads got warm but not hot and the motor on the compressor only got to it usual temp.

so decent 15amp leads should cope easily with a 10amp load over 120m in my experience.

[isuzurover]

If you scroll down to the bottom of this page there is a chart with voltage drop over distance for a given wire size.
Industrial Extension Leads Maximum extension lead length (http://www.industrialextensionleads.co.uk/maximum-extension-lead-length-3-w.asp)

In practice you can see how hot the leads get. If they get too hot IME the plugs will start to melt/distort.

[Chops]

We used to run the shearing shed from a single lead of 10amp, about 45mts, then a 15amp, about 55mts with no problems. Ran the lights, shearing unit and radio and sometimes a fan all at once, and at other times and ran my stick welder down there.
Never had any issues other than sheep pulling the plugs apart :mad: ,,,, soon fixed that though. The hardest part was rolling it all up when we were finished. :(

[Killer]

Why not run the compressor directly at the power source and run long hoses. My compressor blows fuses when connected to a 25m lead. If you are worried about pressure loss with that length you may need bigger diameter hose, or maybe a second air reservoir at the shed.

Cheers, Mick.

[ozeraser]

You know it would be less loss if you ran a long air hose :) (damn Killer got in first :p )

Voltage Drop Calculator (http://www.calculator.net/voltage-drop-calculator.html)
find the thickness of your cable, find the amperage drawn by the compressor.

[bee utey]

I would run the power feed first, then build the shed...
You can fit a stand alone JB/Distro board at the shed site and plug into that.

Just changing the order around [emoji6]
Wot he said. 120m of extension cord is pushing your luck.

http://www.aulro.com/afvb/attachment.php?attachmentid=116076&stc=1&d=1478146098

[Beery]

Voltage drop is going to be a killer if you're trying to pull 15A throught that length. Even the 15A leads are only about 1mm2 cores. You're 15A compressor motor will try and compensate for the low voltage by drawing even more current...and so the problem perpetuates.

It'll struggle to restart once its starting under load with pressure in the tank.

Like Tombie said, reverse the construction plan.

[Trout]

Dads old shed was about 100m from the house. He ran all his tools on lead for years. You used to have to listen out for the compressor as some times it would not start under load and the motor would stall. :o

[Homestar]

I made and used a 100 metre lead once for a similar thing without issue - as it was temporary - like yours will be Murray, go and buy a roll (100 metres) of 2.5mm twin and earth TPS - the cable that's used to run to power points from the switchboard in your house. It's not too expensive if you don't go to Bunnings - go to your local Electrical wholesaler.

Get a heavy duty 15 amp plug and socket (they have larger holes for the cable to go through) and fit these to the whole roll of cable. You won't get the whole bit of TPS into the plug and socket, just the wires, then some tape around them and your done. Should be able to run anything through that - just use a standard 15 amp extension lead for the last 20 metres.

A 15 amp compressor may be pushing it, but the 10 amp unit will work fine.

I think the word most people have missed here is the 'temporary' bit - Murray said nothing about needing power there once it's built or that he would be running permanant power, he just needs a temp supply. Running through leads will be fine over this distance, don't get hung up with all the voltage drop calculations - yes, you'll have a few less volts at the other end, but most equipment - including your compressor - won't care - it will just draw a bit more current to do the job.

EDIT - just worked it out and you'll only get around 10 volts drop across the 100 meters of 2.5mm TPS with an 8 amp load (about what your small compressor will draw when running. A couple more for the other 20 meter lead and your done.

Go for it. :)

[rovercare]

Just cause I enjoy watching the advice on offer:D

[AK83]

..... I need to get power there just while I'm building the shed, it will be wired up at a later date.
.....
Cheers, Murray


.....
I think the word most people have missed here is the 'temporary' bit - Murray said nothing about needing power there once it's built or that he would be running permanant power, he just needs a temp supply. .....

I think the best way forward and save some money in the long run is to take Tombie's advice too.

Why waste money on 120m of leads that may not be fully up to the task, when the inevitable permanent power link is going to be done anyhow!

Another thing is to worry about is the quality of any cobbled together leads which are almost certain to be made in China .. and the recent spate of faulty or sub standard products(especially in the building sector) coming from China would be a cause for concern .. especially electrical.

start digging the trench!