Introduction: How to Wire a Shed for Electricity

Versión en español

I found myself in need to move my noisy woodworking to my back yard to avoid waking up my lady who works night shift. I decided to wire my shed and after some homework and the help of the Instructables community I started my project. Before we start I assume that you know how to wire the different fixtures.

First you will need:

Step 1: The Right Conduit

The right conduit to use is a liquidtight conduit approved for use underground or outside installations. It is a metal conduit covered by resistant plastic. You should find out if there is a code regarding buried electrical lines. My conduit will be buried between 18" and 24". You do not need to worry about frost lines because you are dealing with electricity and not pipes carrying water.
I bought 50 feet of conduit, more than the distance between my house and my shed. The conduit will be connected to a switch box in my basement and to a junction box inside my shed.
You will need an electrician's fish tape to pull the wire inside the conduit. If you find difficult to pull the wire there is a clear lubricant that you can use to make the job easier. Make sure that the lubricant dries before you connect the wire to the main box.

Step 2: Wire

The wire that I got for this project was a type 12-2. It is the right wire for home wiring and for my needs in my shed. Make sure that the wire is inside the conduit before you start the installation.
I became aware that it is against electrical codes to use sheathed cable inside a conduit. Therefore you need to pull three unsheathed wires inside the conduit with a fish tape.
  • Black wire for the "hot" or "live wire"
  • White wire for the neutral
  • Green or uninsulated wire for ground

Step 3: Switch Box

The switch should be inside the house for safety reasons. If you need to turn off the electricity that goes to the shed, the wire underground outside the house will not be energized. Also you will be able to turn off the electricity when you leave for vacation.
One end of your conduit will be connected to this box. When all the wiring is safely installed you can wire the switch to your home electrical panel.

Step 4: Digging the Trench

I dug the trench to bury the conduit by hand ( I mean not literally but with a shovel). I dug for several days, taking my time. If you want to spend some money and rent a trench digger you can but money was an issue for me so this old man decided to dig the trench himself and do it at his pace.
I found a large rock while digging and I did not have any dynamite to blast it so, I patiently dug around it.

Step 5: Wiring the Shed

After I determined the best location for the junction box, I built a panel where I could keep everything together: the junction box, the electrical outlets and the light switches.
I drilled pocket joints in two pieces of 2 x 4 and screwed them to the supporting studs. Then I screwed a 3/4 inch board on the 2 x 4 's.

Step 6: Connecting the Circuit to the Switch and the Main Box

I selected one of the basement windows the entry for the liquid tight conduit. I drilled the hole in the window using a spade bit big enough for the conduit to go in. I connected the conduit to the switch box thus allowing me to turn the electricity off when on vacation.

Step 7: And There Was Light, and the Light Was Good!

Finally I can set my tools to work in or around my shed. My dear wife will be very pleased that I move my noise making to the backyard. A future addition will be an outside motion light. I hope that the information will inspire you to do the same and give ideas.

Comments

author
Rj3lambe16 made it! (author)2017-04-05

Although using liquidtight to bury might be acceptable by code, it still is far from professional. Using PVC or UF wire would be the professional way to wire a shed. Not to mention ising PVC would be much less of an eye sore if done correctly.

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Supertux made it! (author)2017-01-06

Thanks for the help but is it legal.

author
APPLESLAYER1551 made it! (author)2016-08-19

this did not tell me how to wire a shed no help at all

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blkhawk made it! (author)blkhawk2016-08-19

If you don't believe to be skilled enough to work with electricity then by all means hire an expert.

author
Garfielda made it! (author)2016-08-13

We are renting shed and want to run electric for an AC. No one will be living on the property will it be OK to skip the conduit? It will only be hooked up temporary for 1-2 months max.

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blkhawk made it! (author)blkhawk2016-08-14

You can use direct burial electrical cable.

author
Tombooya made it! (author)2016-02-23

I Got a small hunting shed its 12x40 I want to wire it to beable to live in for a week or two at a time. Of course I can't afford a electrician. So I have to tackle it by myself Lord help lol. Want I want to know is can and how would I wire from a generator which would act as the house I'm hopeing. Any help would be great thx.

author
blkhawk made it! (author)blkhawk2016-02-23

Check this Instructable for ideas:

https://www.instructables.com/id/Easy-Generator-to-Home-Hook-Up/

author
Retanotech made it! (author)2012-05-14

what about shop vac and parachute to pull string through burried pipe or unburried pipe to then pull wire?

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blkhawk made it! (author)blkhawk2012-05-14

Have you tried it?

author
Tombooya made it! (author)Tombooya 2016-02-23

Tombooya Reply
I Got a small hunting shed its 12x40 I want to wire it to beable to live in for a week or two at a time. Of course I can't afford a electrician. So I have to tackle it by myself Lord help lol. Want I want to know is can and how would I wire from a generator which would act as the house I'm hopeing. Any help would be great thx.

author
RogerD4 made it! (author)RogerD42015-02-17

Yup - won't pull past an obstacle any better than wire/tape BUT it pulls faster if there is none. I did 350' in two runs and decided to try the vacuum. A little 'plastic bag' with the 'seal' part pulled off and 'tied' in half and a vacuum, mighty quick!

author
altontoth made it! (author)altontoth2013-09-29

Using a vacuum and a small chunk of plastic is actually QUITE common for long pipe runs in the electrical industry, though I've never tried it on flex, so it may or may not work.

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buck2217 made it! (author)2015-06-28

Good I'ble well set out thanks

author
dufus2506 made it! (author)2013-04-28

You should never run jacketed wire through a conduit. You should buy the spools of individual conductors, and use those.

Part of a wire's rating (how much current it can carry) is it's ability to give up heat. If you put insulated wire into a conduit, it becomes like a little oven trapping the heat that the current creates.

If you MUST use jacketed wire, you should de-rate the wire. So, a 12 gauge wire that would normally be rated for 20 amps, would instead have a 15 amp circuit breaker.

Be safe.

author
irishalan made it! (author)2012-12-09

hi i could do with your help would i be ok wiring frima double plug socket in house to shed .i got two little sheds out back joined to each other first one i want one double plug socket one switch one celling light. next i want to drill through to second shed have two double plug sockets one switch one celling light i all ready have one of the double wired in from house i can use it for chop saw light eg; i wont be uesing every thing together but need to know if one double plug from house be enough irishalan ta

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blkhawk made it! (author)blkhawk2012-12-13

Your setup should work. Make sure that the wire or extension cord that you plan to use is approved for outdoor use.

author
mrbigtw made it! (author)2012-12-13

Hello, thanks for this writeup. I'm looking to do something similar for my shed. I'm thinking 2 overhead lightbulbs with switch, a very small window like a/c unit in the summer,and small space heater in winter, and a couple other outlets for skillsaw, etc. Its about a 75 foot run, so I'm almost thinking 10 gauge, 20amp. Maybe 30 amp breaker? I'm curious about your wiring to your mainbox. Do you have this line with a new single breaker box and also a breaker in your mainbox? so a double breaker?

author
blkhawk made it! (author)blkhawk2012-12-13

The small box that you see is only a switch to turn the electric off at the shed whenever I am on vacation or if I am performing an electrical upgrade in the shed. I am not an electrician and I am not sure about the power requirement for your a/c and heater. You could post a question in the Question and Answers forum to find out the breaker amperage rating needed.

author
evad made it! (author)2012-02-17

I'd think about adding a ground fault interrupter type outlet...

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blkhawk made it! (author)blkhawk2012-02-17

Thank you for the suggestion. I also thought about it, since most of my woodworking is done outside the shed.

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tinker234 made it! (author)2011-10-16

excuse me could i somehow make a quick removable system for this

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blkhawk made it! (author)blkhawk2011-10-18

If you have an idea, please share with us!

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tinker234 made it! (author)tinker2342011-10-23

well i was thinking of using telescopic rods that would run from my home to the shed

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lemonie made it! (author)2010-08-29


Useful I like it. However, I notice the NM-B cable says "INDOOR" on the pack, and is intended for normally dry conditions - you are confident that it will last in the ground?

L

author
altontoth made it! (author)altontoth2010-08-29

Although technically you shouldn't be running a multiconductor cable like that through a conduit (dissipating heat is harder for a cable in pipe), the outdoor rated cable is typically intended for direct burial (to full voltage yard lights, for example). When I did a friend's shed, we used PVC pipe ($8-10 per stick), and bought the wire (3 separate conductors, not as a cable). Also picked up a yard plug this way (put a PVC elbow into a bucket with a small post, poured concrete, planted it in the ground). Cheers

author
blkhawk made it! (author)blkhawk2010-08-29

If a wire gets too hot it means that the wrong wire is used. Liquid tight conduit is approved to be used outside or buried. PVC is commonly used but I would not recommend it because it is not designed with weatherproofing in mind. If you rather use PVC, wouldn't you run with the same overheating problem like you claimed?

author
2 stroke made it! (author)2 stroke 2011-06-24

sorry a little late but i use the grey electrical conduit made of pvc it is made by scepter and is approved for out door use and my wire inside does not get hot it is fine but liquid tight is better and easier to install if you are wiring under ground like you did my uncle is a electrician so im sure he did a good job :P

author
2 stroke made it! (author)2 stroke 2011-01-24

i run indoor cable 12/3 romex through a conduit to outside my house from my garage breaker panel where i do my welding its about 12ft of a run for the cable through PVC conduit and i use a small 120 volt welder with full 20 amp draw i think you should be fine for wood working, liquid tight under ground u should be fine :P

author
altontoth made it! (author)altontoth2010-08-31

PVC is used in ground level slabs in commercial all the time. The point I'm trying to make is that you're not supposed to pull a multi-conductor line voltage cable through any sort of conduit (PVC, EMT, and liquid-tight). That's actually in both the CEC and the NEC (as far as I'm aware...at least the Canadian Electrical Code). Though to be perfectly honest, if it's just a shed, it doesn't really matter HOW it's done, as long as it's not an installation for someone else, and you're the one who's happy with it and it's safe.

author
altontoth made it! (author)altontoth2010-08-31

Hm. And of course, when I go to look up the specific rule numbers. I can't find it. I know that it was quite clearly drilled into our heads through three years of electrical training that if a line voltage multi-conductor cable is going through a raceway, it's for a limited distance only, to protect against mechanical damage. But, lacking the actual page number etc, I'll rescind my point regarding conduit.

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blkhawk made it! (author)blkhawk2010-08-31

Thank you. I thought that I was doing everything right. (Proverbs 9:8-9) "Give a reproof to a wise person and he will love you.  Give to a wise person and he will become still wiser. Impart knowledge to someone righteous and he will increase in learning"

author
nagehmai made it! (author)nagehmai2010-08-31

Its technically against code to run regular indoor sheathed 12/2 Romex inside an underground conduit. The reasoning behind this is, as altontoth mentions, is due to heat dissipation issues. You can, however, run unsheathed wires inside the conduit instead. Since you're just powering a shed, you're not likely to burn anything up with what you've done though. Another, and probably cheaper alternative for anybody else looking to do this, is just to drop direct-bury NMWU Romex into your trench and forget about the conduit. This is what I used to run power to my chicken coop.

author
blkhawk made it! (author)blkhawk2010-08-31

I thought about running the direct-bury cable but I thought that the wire needed some type of protection. Thank you for the suggestion.

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blkhawk made it! (author)blkhawk2010-08-29

The liquid tight conduit is weatherproof and waterproof. Its purpose is to protect the wire inside but to be on a safer side I could also use cable designed for underground or outside applications.

author
lemonie made it! (author)lemonie2010-08-29


It's down to the conduit I guess. Waterproof should do it.

L

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vincent7520 made it! (author)2011-02-05

Yes it's a real mess and it is also an example of the american contrast : the american are the only people on earth who can send men to the moon or on mars, but I never saw a domestic electric installation which was not a mess like that … 
In europe regulations are so stringent that no handyman would accept to leave an appliance in such a mess : he would be held responsible and the insurance would not cover it ! … 

how funny : same techniques vs different countries / culture => different benchmarks !…

author
Hycro made it! (author)2010-10-03

Man, I would have broke out the hammer, safety glasses, and face shield and broken the rock...but, that's just me...

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beehard44 made it! (author)beehard442010-10-06

i would just make a huge fire pit with the rock as a centerpiece and have a BBQ party using a huge fire pit and pouring severely cold water over the rock.
Done.

author
geo_caver made it! (author)2010-10-04

I am surprise that you did not use PVC pipe as a conduit for the wires as a security against potential animal gnawing or even accidental cut off by simple root removing process or gardening.

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blkhawk made it! (author)blkhawk2010-10-04

I used liquid tight conduit but I might as well used a direct burial cable. It is against electrical codes to use a conduit with sheathed cable inside.

author
NachoMahma made it! (author)2010-08-29
.  I see two huge problems.
  1. There is no ground! You need to use 12/2 with ground cable.
  2. It looks like the conduit runs downhill toward your box in the first picture of step 6. This will allow water to intrude and it will flow straight to your electrical box. Move the box up a few inches. Make sure the conduit starts uphill as soon as it enters the basement to minimize water leaking in.
author
blkhawk made it! (author)blkhawk2010-08-29

The wire does have ground and once the conduit goes in the shed the conduit goes up and it is connected to a junction box.

PICT0206.JPG
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dave566 made it! (author)dave5662010-09-04

Im pretty sure I see a green ground screw in there for bonding the box to ground. Nice work most people ever look that.

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blkhawk made it! (author)blkhawk2010-09-10

Thank you for noticing. I became aware of the importance of correct grounding when I was studying for my A+ Certification Exam. A lack of proper grounding is not only unsafe, it is harmful for electronics like computers and other devices.

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NachoMahma made it! (author)NachoMahma2010-08-29

> The wire does have ground
. Sorry about that. I think I need new glasses.

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blkhawk made it! (author)blkhawk2010-08-29

My glasses will be ready in a week. First time ever! Old age is creeping up on me.

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dhandel1 made it! (author)2010-08-29

Your land lady is fine with you running cable? are you a licensed electrician? If not, I don't think you should be giving advice to people (especially those who have never worked with cable before). I work in the real estate industry, and I know an accident waiting to happen when I seen it. IMHO call a professional when it comes to electrical and gas... is saving money really worth the very possible risk of fire?

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blkhawk made it! (author)blkhawk2010-08-29

As a matter of fact my landlady is very happy with me! Thank you very much. Some states do not require a licensed electrician to perform every single job in your house. Now if you want to be constructive and you feel that you are a qualified expert point out the danger and I will be more than willing to work on the problem but you are not going to intimidate me by saying that you work in the "real estate industry" a very vague title by the way.

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dave566 made it! (author)dave5662010-09-04

To work on someone else's house you do need to be licensed even if it's something as simple as replacing a light. Only if you own the house can you technically do electrical work. Just use common sense and know when a project is over your head.

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