# Burying electrical to a shed???



## Beeman (Dec 29, 2002)

I need to bury an electric line to a shed. Has anyone used direct bury romex type wire? I plan on running a 12-2 with ground and wonder if the romex is better or as good as conduit.


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## YuccaFlatsRanch (May 3, 2004)

Just going to a shed I'd bury the romex, but mark where it is to keep you from digging through it in the future. Be sure your wire run isn't too long for 12/2.


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## fishhead (Jul 19, 2006)

If you have pocket gophers be sure to protect the wire. I buried 900' of wire and the gophers ruined it before I could even finish hooking it up. When I pulled it out of the ground it looked like they took a slice every inch for much of it. The longest stretch that was any good was about 20'.

$500 down the drain plus I had to rent a trencher again for $100.

There are online calculators that will tell you what size wire you need for different length runs.


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## Spinner (Jul 19, 2003)

ground critters will chew thru the wire, it needs to be inside gray pvc pipe.


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## fishhead (Jul 19, 2006)

In order to be gopher proof it should be 2" in outside diameter although my electric company assured me that 1 1/2 schedule 40 pvc was enough.

I don't understand why they don't put a gopher repellant/poison on the coating like they do with natural gas line.


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## tiogacounty (Oct 27, 2005)

First, Romex is a brand name for a cable designated NM for non-metallic. It is not designed or approved for direct burial. It has a very light outer jacket and it can easily be damaged by sharp backfill. I have used it for temporary situations where it was buried, and it fails pretty easily. The direct burial cable is called UF for underground feed. It has a much tougher jacket, it is more expensive than Romex, harder to skin, and much more durable. Personally, I put everything in PVC conduit. It adds little to the cost and prevents a lot of headaches. Good luck.


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## Beeman (Dec 29, 2002)

tiogacounty said:


> First, Romex is a brand name for a cable designated NM for non-metallic. It is not designed or approved for direct burial. It has a very light outer jacket and it can easily be damaged by sharp backfill. I have used it for temporary situations where it was buried, and it fails pretty easily. The direct burial cable is called UF for underground feed. It has a much tougher jacket, it is more expensive than Romex, harder to skin, and much more durable. Personally, I put everything in PVC conduit. It adds little to the cost and prevents a lot of headaches. Good luck.



I just used the name romex to describe the type of cable, didn't know the right name. I've always run everything in plastic conduit before, I guess I was just looking for reinforcement of what I've always done or a cheaper easier way to do it. I've always pulled individual wires thru the conduit, is that what everyone else does?


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## hunter63 (Jan 4, 2005)

Buried 250' romex UF 10-3 wire,(wanted 20 amps), using a spade to cut the slit, then pushed wire down into slit. called a farmers trench around here.

Been there about 10 years no problems.

Used 10-3 as it gave me two 110 circuits with the long run 250'.
Went down the hill from the pole/breaker, to the shed. Still does.
Cost about $180 bucks then, hate to see what it would cost now.

Actually had to dig it up for the cabin site prep, then rebuired it again 2004.


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## Jolly (Jan 8, 2004)

I've got UF in gray conduit, but I'm kinda a belt and suspenders kinda guy.

Murphy was an optimist, you know....


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## e.alleg (Jan 13, 2006)

I JUST last week bought a 250' roll of 12/2 (plus the ground) UF-B direct burial cable on Ebay. $112 delivered. $140 at the home store plus tax and the requisite soda/candy for all the kids so ordering online was a pretty nice savings. I dug the trench by hand 2' deep, it takes some time but at 2' nobody is likely to hit it by accident. All I use it for is one light in the chicken coop and maybe a freeze-proof waterer in the winter so 12/2 is fine. If you plan on using a lot of electricity go with a larger wire, it will save on your electric bill in the long run and prevent any problems associated with the voltage drop. For a garage or workshop where you want a permanent maintenace free power line I would use 8/3 in conduit buried at least 36" deep with a few inches of sand below and on top of the conduit. Sit down when buying the large cable. OUCH!


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## fishhead (Jul 19, 2006)

I just bought 300' of 4-4-6 aluminum overhead wire for a buck a foot.

When I buried the 900' of underground line I fed it through each section one at a time without gluing the sections. Then when it came time to bury it I made sure to force each joint together so there was no way for a gopher to get at the wire. I just used schedule 40 pvc and not the schedule 80. Both pipes almost satisfy the 2" outside diameter that prevents a gopher from getting a bite on the pipe and according to my power company that's close enough. So far so good and the buried pipe trench is still a major highway for any gopher that comes through.


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## Old_Town (Dec 13, 2006)

Beeman,

As the others have said, I would run the circuits in Sch. 40 PVC. I would also oversize it by one size. If you ever want to increase your ampacity you will have a pipe large enough. Make sure you use long sweep "electrical" elbows and not plumbing fittings. 

Good Luck,
Ty


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## Ramblin Wreck (Jun 10, 2005)

I think PVC would be better, but I bury mine inside black plastic pipe like you sometimes see used to run water lines. In our area you can buy it in rolls of 200 feet or more. It's cheaper than PVC, and I've been able to get complete runs to buildings without splicing (meaning it installs quicker since there is no sections to glue together). You will have amp/voltage degradation on long runs, so plan accordingly. Good luck.


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## tiogacounty (Oct 27, 2005)

Ramblin Wreck said:


> I think PVC would be better, but I bury mine inside black plastic pipe like you sometimes see used to run water lines. In our area you can buy it in rolls of 200 feet or more. It's cheaper than PVC, and I've been able to get complete runs to buildings without splicing (meaning it installs quicker since there is no sections to glue together). You will have amp/voltage degradation on long runs, so plan accordingly. Good luck.


 As A long time electrician, I can't figure out why more people don't do this? Technically, it's not a code approved conduit, but it's tough, fast to install, and cheap. I wouldn't hesitate to use it.


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## Old_Town (Dec 13, 2006)

tiogacounty said:


> As A long time electrician, I can't figure out why more people don't do this? Technically, it's not a code approved conduit, but it's tough, fast to install, and cheap. I wouldn't hesitate to use it.



There is a product that is approved for direct burial for power that is essentially PVC on a huge roll. It sometimes has the pull rope in it and even wire ready to lay in the ditch. It's a product like innerduct but for power. I have never run any but I have seen it.

It really does not get much easier than schedule 40 PVC. It's long lasting, cheap , corrosion proof and easily installed. I like to use galvanized rigid elbows at the pulling end so the pull rope won't cut into the PVC elbow. Make sure you use plenty of pulling lube on the longer runs. 


People often try to slip the conduit over the wire and build the raceway as they go. Not only is this more labor intensive, it's against NEC code.


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## daytrader (May 8, 2005)

ok, The under ground quality romex. is good stuff. Just wait a sec.

I would ALWAYS use conduit. Even with the under ground romex.

The reason. Romex has a BAD problem of working its way up. When in cond or even plastic plumbing pipe. It is much harder to work its way up.

The first time you are mowing the greass and take on some romex, you will know what I mean. 

Buy good quality romex and use simple plastic water pipe. It isn't that much more.


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## Old_Town (Dec 13, 2006)

There really is no need to run "romex" of type UF sheathed cable inside of conduit. Type THHN single conductor wire is designed to be pulled in conduit, not multiconductor sets. 

Running romex or UF in pipe is a complete waste of time and money.


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## Jim S. (Apr 22, 2004)

Beeman, you live in TN. It is required in TN that your line be in conduit. Good reasons, too:

1.) Direct to ground lightning strikes are frequent.

2.) There is rock in the ground that can move and damage wire, allowing water infiltration.

I had some direct-bury from a previous owner. Both of the above made it necessary to replace it all over time with conduit. I used the direct-bury inside plastic conduit. Double protection if water does get in the conduit. Romex is banned from underground use by code.

Old Town is correct, you can opt to use single conductors approved for underground use.

Schedule 80 is acceptable under TN and national code for all portions of your wiring that are underground. The portion of your conduit that extends aboveground to connect the building or whatever MUST be Schedule 40, however, to meet code. They require the 40 aboveground because it has greater impact resistance.

Using Schedule 80 underground saves a bit.

The bury depth on your wire is supposed to be 2 feet.

If I were doing it, I would run 10-2. That provides you the opportunity to upgrade later to 220 service in the 30-50 amp range, depending on the length of the wire used. Otherwise, you would have to tear it all up if you ever wanted to upgrade for any reason.

You will want to protect your wiring on both ends with a fuse or circuit breaker. This is national code for a subfed wire to an outbuilding. Small single-breaker boxes are cheap for the shed end and adequate for 110 single circuit work.

You are required under code to run your conduit up the outside of your building, then either (ideally) directly through the wall into the fuse or circuit breaker box, or no more than 3 protected feet to get to it. Then your branch circuits run from that. I say this because the most common error is, folks will run it inside. That violates the code.

You can see the Schedule 40 conduit going up the side of this building...










It feeds through the wall directly to the panel...










Be sure you measure twice before you get your wire. By code, there can be no connections between each fuse box, it must be a single run. Don't come up short.

Hope this helps. I have run a LOT of underground wiring in 4 states, all of it inspected.


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## farminghandyman (Mar 4, 2005)

It is my understanding your to use schedule 80 conduit as it exits the ground if it is in a "Area of Physical Damaged" zone, which is usually considered the first 8 feet (from ground up and be protected down 18"),

And I am reasonable sure there is to be slip/expansion in RNC joint in the conduit as well. nec 352.44 I believe is used to determine this.

If it is direct bury it has to be 18" with a warning tape placed 12" above the wire,300.5(d)(3)
Direct burial cables of UF or USE are to be 24", nec300.5 table. there is a table with a chart to show type and where located for the depths of bury.



> this from 2005 nec,
> NEC 300.5
> (D) Protecting Underground Cables and Conductors from Damage. Direct-buried conductors and cables must be protected
> from damage in accordance with (1) through (4).
> ...


an illustrated guide to a basic understanding of the National Electrical Code
(this is not the entire code but it hits many of the major high lites.)
âTop 101 Rulesâ from Mike's Understanding the NEC, 2005 

http://www.mikeholt.com/download.php?file=PDF/Top101RulesUNEC-1Part1.pdf

http://www.mikeholt.com/download.php?file=PDF/Top101RulesUNEC-1Part2.pdf

http://www.mikeholt.com/download.php?file=PDF/Top101RulesUNEC-1Part3.pdf

http://www.mikeholt.com/download.php?file=PDF/Top101RulesUNEC-1Part4.pdf


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## Nel frattempo (Mar 29, 2007)

I do not know about wire types BUT do be careful where you bury it. When we bought our property, we did not know the location of the electric wire to the barn and a shed, the boys were digging to put in more post holes around garden, it was wet and drizzly and when they touched the wire fence it shocked them! The former owner had the metal wire fence touching the electric line! So - careful! Good luck


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## Andy Nonymous (Aug 20, 2005)

Hey Jim Steele, I've done a fair amount of electrical work (over the past 30 years), and it seems you have your schedules reversed: according to ASTM, for metal as well as plastic pipe, schedule 40 is 'standard', schedule 80 is 'heavy wall', and schedule 20 is 'thin wall'. Sch 40 Rigid Metalic Conduit or PVC is good for direct burial, and RMC or sch 80 PVC required where subject to physical abuse (such as on a pole, or side of a building). I did install one service with rigid sweeps and risers and sch 40 PVC between them, requiring bonding bushings on each end of the run, but usually try to use PVC the whole length, and bring the pipe up on the inside of a pole buildiing (as your example appears to be) and into the bottom of the panel - PVC does get brittle with long exposure to the sun, it makes for one less hole / air weather leak into the building, saves effort in running wire (especially the larger sizes) through an LB, potentially reduces condensation in the pipe (inside vs outside temp swings), makes it easier to re-side in 40 years, and it's one less thing to weedwhack around.

Just my two coppers.


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## farminghandyman (Mar 4, 2005)

Jim S, First: I am not picking at you, but one other item in the picture.

I see a gas hot water heater, there, it should be set on a platform 18" off the floor, in a garage or shop area, flammable fumes could be ignited by the pilot lite or burner, (gasoline and LP, as well as some solvents, are or can be heavier than air and can set on the floor).
(and is covered in both the IRC 2801.6 and UPC 508.14), 
I do think this item is for your safety, 

but I have see one shop go up in flames by a similar situation,

(IRC International Residential Code),
(UPC Uniform Pluming Code),


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## Old_Town (Dec 13, 2006)

Andy Nonymous said:


> Hey Jim Steele, I've done a fair amount of electrical work (over the past 30 years), and it seems you have your schedules reversed: according to ASTM, for metal as well as plastic pipe, schedule 40 is 'standard', schedule 80 is 'heavy wall', and schedule 20 is 'thin wall'.



That's right. The inside diameter of Sch. 80 is smaller due to the greater wall thickness, because of this I like to again, oversize the pipe to facilitate the wire pull. I am not a big fan of any PVC run above ground. Even sch. 80 degrades quickly in a direct sun environment. I like to use rigid steel, IMC or in some cases EMT for the above ground portion of the conduit run. 

I have little use for direct burial cables. They are expensive, labor intensive and troublesome. I have seen very few underground circuits installed in PVC that have failed. On the other hand, I have seen numerous direct buried circuits that failed, in often a relatively short period of time. I have been a licensed electrician since 1996.


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## farminghandyman (Mar 4, 2005)

I had a job one time where the people want an addition on to there double wide modular home, and the modular sat where there there old 10' wide trailer has sat, 

I asked where do I get temporary power for the tools, and they suggested use the old trailer feed under the house to tap power off of, (I set a small pole and then a breaker box and the plugs are on it, and then wire into or have a power company bring power to it, as a temporary service), 

any way I get under there and find it and make up a plug to fit it, and plug it in and it is dead, go to the distribution pole and the main breakers are on the pole is on, and all the wires in the box are conected, HUM so I go out to the edge of the modular and start to dig a cross trench to locate the wire trench, I locate the wire trench and carefully dig down along side of it and then locate this burnt path in the ground where it had arced it way in to dust, so I take a guess and try again about 50' closer to the pole same situation, 

I report to the owner the situation and show him the problem, 

so I had the temporary wired into a different location, 

To my knowledge he has not to this day disconnected the old line that is burning away under ground back to the distribution pole, (I left that up to him as he was the "electrician" on the job).
I can not imagine how much in electricity that has cost him to let it bleed in to the earth, that was 10 to 15 years ago,


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## Jim S. (Apr 22, 2004)

Yer right. I reversed 'em. Everything has its drawbacks. Metal rusts in a high humidity/rain environment. Hardly used in my area of the the South. Even the utilities use PVC.



Andy Nonymous said:


> Hey Jim Steele, I've done a fair amount of electrical work (over the past 30 years), and it seems you have your schedules reversed: according to ASTM, for metal as well as plastic pipe, schedule 40 is 'standard', schedule 80 is 'heavy wall', and schedule 20 is 'thin wall'. Sch 40 Rigid Metalic Conduit or PVC is good for direct burial, and RMC or sch 80 PVC required where subject to physical abuse (such as on a pole, or side of a building). I did install one service with rigid sweeps and risers and sch 40 PVC between them, requiring bonding bushings on each end of the run, but usually try to use PVC the whole length, and bring the pipe up on the inside of a pole buildiing (as your example appears to be) and into the bottom of the panel - PVC does get brittle with long exposure to the sun, it makes for one less hole / air weather leak into the building, saves effort in running wire (especially the larger sizes) through an LB, potentially reduces condensation in the pipe (inside vs outside temp swings), makes it easier to re-side in 40 years, and it's one less thing to weedwhack around.
> 
> Just my two coppers.


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## Jim S. (Apr 22, 2004)

Also sent to me as a PM. You wanted to make sure I saw this.

The water heater, utilities and bathroom are in an enclosed utility room, separate from the shop. All flammables in the shop are stored in a metal cabinet rated for such. Gas is not stored inside the shop, but in a separate, unheated outbuilding. 

The water heater in the picture is not the one currently in use, but the current one is on the floor, on small 3" high legs it came with, so it wouldn't meet 18" height requirement, either. 

It all passed inspection. The first time.

I gotta quit posting pix for illustration. I have posted those before, and got "called out" on other stuff.  



farminghandyman said:


> Jim S, First: I am not picking at you, but one other item in the picture.
> 
> I see a gas hot water heater, there, it should be set on a platform 18" off the floor, in a garage or shop area, flammable fumes could be ignited by the pilot lite or burner, (gasoline and LP, as well as some solvents, are or can be heavier than air and can set on the floor).
> (and is covered in both the IRC 2801.6 and UPC 508.14),
> ...


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## farminghandyman (Mar 4, 2005)

Jim S.

I learn new things all the time and I start looking around my place, and see things that need to be improved or changed many times.

Some things I never even thought about or was aware of  it as a potential hazard.

After that one shop in town went up in flames I took an entirely different view of how serious potential ignition points in the bottom 18" of a building can be. 

And was concerned you may be unaware of the possible hazard there,

and as your own byline Say's 
"I won't tell you what to do, but I'll tell you what works for me."


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## Beeman (Dec 29, 2002)

Here's what I did. A buddy of mine rented a trencher and he had it for a few days so he let me use it. Trenched the run and used 3/4"gray electrical PVC sched 80 above ground and 40 below. The distance is 60' and I haven't pulled the wires thru yet. All that's going on this one is an outlet at the end for an electric fence charger, I have #12 wire for this.


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## Daddyof4 (Jan 5, 2004)

Jim S. said:


> Beeman, you live in TN. It is required in TN that your line be in conduit. Good reasons, too:
> 
> 1.) Direct to ground lightning strikes are frequent.
> 
> ...


From the looks of your water heater system, you used a manifold with PEX flex pipes? How is that working for you? I know this is off subject but I've heard PEX has a high, high level of benzine in it and can cause health problems over time.


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## watcher (Sep 4, 2006)

I used underground approved wire and burried it 3 feet deep. First 100 or so feet I used nothing but a shovel. Then I got my tractor fixed and used the post hole digger to bore a series of holes then used the bucket to dig out a trench. I don't think much is going to bother it 3 feet down.


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## comfortablynumb (Nov 18, 2003)

string extension cords up in the trees where ya can keep an eye on them.


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## Beeman (Dec 29, 2002)

comfortablynumb said:


> string extension cords up in the trees where ya can keep an eye on them.


 No trees nearby and it would cost more to plant the trees then to run the wiring. I did have the extension cord on the ground, but we mow that area and it's a pain to take it up and put it back every mowing.


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