Underground cable to workshop

skinny · Nov 1, 2012

Hi

I am planning to put a cable out to a shed to setup a workshop in there. I use a lot of wood working tools (band saw, lathe, planer thicknesser), plus welder and grinders. Ill also want a lighting circuit. All single phase. The cable has to go about 10 m underground and will go under a stone track. the track gets occassional agricultural traffic.

I dont plan to do the eletrical work myself but im trying to work out the safest most practical way of getting the cable from A-B. I wnt to inform myself before I get prices to get the work done and to work out what donkey work I can do myself.

I ve got a heap of questions and any advice would be most welcome.

How deep should my trench be?
What should I back fill with? we are on a hill and when we hve heavy rain there can be a bit of surface water running down the track. Could sand cause the trench to act like a drain?
Is it a good idea to use some form of conduit underground and if so, what?
what type of cable would be best ? Ill get the electrician to specify exact thickness but it would be useful to know what it be likely to be.
Would it be a good idea to get an earth spike?

Thanks in advance

Skinny

Knobhead · Nov 1, 2012

Ask you're electrician, it's his expertise you're goimg to be paying for.

GLENNSPARK · Nov 1, 2012

Tony said:
Ask you're electrician, it's his expertise you're goimg to be paying for.

agreed....
get an electrician in...he will do a design based on the expected load demand....volt drop and installation methods...

Steven Brooks · Nov 1, 2012

Hello Friends,

It is not particularly hard to run underground cable to a detached garage or other outbuilding, especially if you have some basic wiring experience. If you have no experience, then, please take advice from a good electrician other wise it will be a big risk for you.

Thanks and Regards,
Steven Brooks

diditrain · Nov 1, 2012

[ElectriciansForums.net] Underground cable to workshop

hope you can see the image clearly

jumpin jax · Nov 1, 2012

Why not put a 32mm duct or bigger in and then the electrician can then put the cable of his choice in and you have then done the excavating work ready

Phillcbr400 · Nov 1, 2012

Agree with jax, speak to your electrician first too get a design together and you do the ducting.

Octopus · Nov 1, 2012

I think the key he is "under a track used by occassional agricultural vehicles" and thus deeper PLUS mechanical protection would be a minimum.

As others have said get a couple of sparkies round and see what they say but I'd say that the depth should be greater.

High Tower · Nov 1, 2012

I would say the depth will need to be at least a metre, with a loose top surface that won't distribute any weight, and the promise of a tractor or two "me lovers"!! (sorry couldn't resist). The cable needs bedding in on sand, it needs a cable tile and warning tape.

However with the kind of loads you describe you will need to consult a spark as there are quite a few calculations to be done to size the cable correctly!!

Engineer54 · Nov 1, 2012

skinny said:
Hi

I am planning to put a cable out to a shed to setup a workshop in there. I use a lot of wood working tools (band saw, lathe, planer thicknesser), plus welder and grinders. Ill also want a lighting circuit. All single phase. The cable has to go about 10 m underground and will go under a stone track. the track gets occassional agricultural traffic.

I dont plan to do the eletrical work myself but im trying to work out the safest most practical way of getting the cable from A-B. I wnt to inform myself before I get prices to get the work done and to work out what donkey work I can do myself.

I ve got a heap of questions and any advice would be most welcome.

How deep should my trench be?
What should I back fill with? we are on a hill and when we hve heavy rain there can be a bit of surface water running down the track. Could sand cause the trench to act like a drain?
Is it a good idea to use some form of conduit underground and if so, what?
what type of cable would be best ? Ill get the electrician to specify exact thickness but it would be useful to know what it be likely to be.
Would it be a good idea to get an earth spike?

Thanks in advance

Skinny

How far are you willing to go, to make this cable trench suitable for it's environment?? I get the impression that you would like this cable trench to also act as a drain to take away a certain amount of this surface water during heavy rains?? That can also be achieved, but as i say, it very much depends on how far your willing to go in as far as work and cost investment.