undergroudn electrical wire

Discussion in 'Shop Talk' started by Bummer1002, Jun 14, 2004.

  1. Bummer1002

    Bummer1002 Well-Known Member

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    Can anyone tell me what I need to do and how I need to do it if I am to bury about 300 feet of wire underground? I will be running it from the house, to a shed out back and will be having it power a small electric fence, and about 4 lightbulbs in a shed.

    Thanks
    Bummer
     
  2. lacyj

    lacyj Well-Known Member

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    Do you want to do it to code or cheaper and easier? DH says that 10 gauge wire would probably work. If you don't want to use schedule 40 conduit(which is code) you could use regular PVC water pipe. It is supose to be buried 3 foot deep, but if you don't plan to be digging in that area, it could be two foot deep or less. You can rent a trencher to do the digging yourself. There is also direct burial wire, that doesn't have to go into pipe. This is more bendable and will go around big rocks and trees easily.
    lacyj
     

  3. rambler

    rambler Well-Known Member Supporter

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    There are niffty little simplified wiring handbooks sold at all the lumber yards & box stores. Under $12. Get one. It will tell you exactly how to do this, and is simple to follow. It will keep you relatively safe & at least close to code. A very, very good investment.

    Do you have a tractor & a subsoiler point? You can use that to make a groove & lay the direct burial wire. It needs to be 18" deep at least, local cose might be deeper or might need conduit or if you are going under driveways or the like.

    You can rent a trencher from many locations, little walk-behind ones.

    It's a lot of work with a shovel, but an option for you.

    Code these days is that you branch off your curicit breaker in the basement with a breaker, run 4 wires to the shed, and put a disconnect or small breaker set in the shed that is _not_ bonded but uses the 4th wire back to your basement breaker.

    If what I just said does not make any sense at all to you, you need to study up on electrical work, or get a semi-pro to do it for you. You could lay the wire, just have them do the connections.

    It is real easy to get 2 wires connected & provide electricity, but done wrong & especially mixed with livestock, it easily becomes a fire or electrocution hazzarm. Might 'work' fine for 5 or 10 years, but some day, the wrong conditions.....

    Sometimes these government types go too far, require too much garbage. But at least the basic idea of the NEC is a good thing, and keeps you & your critters & your buildings safe.

    --->Paul
     
  4. Bummer1002

    Bummer1002 Well-Known Member

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    I'm going to rent a trencher for a half day as it shouldn't take that long, the shed is just about in a straight line from the house. I'm going to definitely be putting it in as close to code as possible. My dad will be taking care of that, he's good at wiring. I guess the only thing I need to know now is, what type of wire to use? He was thinking about Romex?

    Thanks!
    Bummer
     
  5. Tractorman

    Tractorman Well-Known Member

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    Use type UF romex wire it is rated for direct burial and sunlight resistance NEC is 18" deep and future plans will determine if you need a sub panel or just a circuit. A fence charger and 4 bulbs will be fine but if you start runing a air compressor you will have voltage drop issues. I am a licensed electrician so if you have any more question please let me know
     
  6. gobug

    gobug Well-Known Member Supporter

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    Electrical conduit is cheap, and you can run cheaper individual wires through it. The IRC2003 (international residential code) is followed in my county. Wire labeled for burying must be 2 feet deep. But if you use conduit in an area without vehicular traffic it can be 1 foot deep. It can be 6 inches if you cover the conduit with 4 inches of concrete.
    gobug
     
  7. Bummer1002

    Bummer1002 Well-Known Member

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    That's just what I need to know....thanks!

    Great thanks!

    This is going to go right across my lawn, so I guess that's without vehicular traffic.

    So what I have learned so far, is that UF Romex wire is the way to go, and I can have it buried 12 inches underground and still conform to code, and stay safe.

    Thanks guys, any more input or advice is appreciated!

    Bummer
     

  8. Huh???? 18", not 12". You said you are going direct burial right? Not conduit?

    --->Paul
     
  9. SteveD(TX)

    SteveD(TX) Well-Known Member

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    I just finished a long (700 ft. ) underground electric run. Had an electrician design the system and do final hook-ups and I did the rest. Did TONS of research on this before I started. Still, I'm no expert, but if it were me, I would go with a little heavier wire just in case in the future you want to run some tools, etc. in the shed. Also, if you have gophers, moles, etc., you might not want to do direct burial wire. I have them, and went with the grey shed. 40 pvc conduit buried 18" deep. Using no. 6 awg wire would allow for heavier future use and the voltage drop associated with a 300 ft. run. Also, you might find that a sprinkler co. will dig your trench for you just as cheaply as you can rent a machine for half a day. Good luck and listen to the licensed electrician for further advice.
     
  10. comfortablynumb

    comfortablynumb Well-Known Member

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    I agree, for all the more it costs i would use 60 amp line cable. then of you want to run something out there you wont go "ahh crud we shouda"
     
  11. Even though direct burial 10 guage romex is the way you should go, I would suggest you buy one of those long coils of inexpensive black plastic tubing (at home or garden center) to lay down. Since the cable you are using is rated for direct burial, there is nothing that says you can't run it through the cheap tubing. If you ever have to replace the cable (for example you run your post hole driller through it or you are trenching for a water line, need to upgrade, add a circuit, etc.), you can easily do it. This will give you a little more protection from burrowing rodents or when you are digging with your shovel to plant that new fruit tree. No matter what kind of conduit, pipe, or tubing you use, I would always use direct burial cable outside even though it costs a little more. If you ever have a breach in your pipe, there is no problem. You can even branch off the center (carefully, with the power off when working) in the furture without having to seal the pipe joint (as long as there are no unsealed splices in your cable).

    Note: You can use a vacuum cleaner hose to suck a string through the conduit to pull your cable. You may need to tie a wad of cotton or ball of paper on the end of the string.

    You may consider using 10/3 because of distance and plan on hooking it up to two legs in your breaker box if you have the room. If both circuits are on the same 'leg', the current will be limited to the capacity of the shared neutral. One circuit can be used for lighting and the other for convienience outlets. I would also suggest you place a small breaker box in your shed. Use 15 or 20 Amp breaker in the shed for each leg and a dual 30 Amp breaker (interlocked so entire line between the two boxes is either off or on) at the house.

    Plan for a ground-fault circuit for your outlets in your shed. You will have to get advice from someone else on whether a fence charger will work on a ground-fault protected circuit since a electric fence works on the principle of creating a ground-fault (part of the circuit is through the ground).

    If you are a true homesteader and you want/need (or can't resist the urge for) your project to grow beyond what you had originally planned, you may wish to run a water line at the same time. Most would probably suggest you use a seperate trench, and while you have the machine and know where the first one is and you will be laying the pipe anyway, you may as well run water when you are in that state of mind. Seek advice of others whether it is advisable to run water line in same trench as electric line. I have in the past, though some would argue it is more difficult to repair a water leak with both pipes together in the same trench.

    Dale in Tx
     
  12. Bummer1002

    Bummer1002 Well-Known Member

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    Thanks a lot for the good ideas, especially about using a shop-vac to such the string through. I really appreciate them.

    Bummer
     
  13. joan from zone six

    joan from zone six Well-Known Member

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    and then, after you have your conduit, waterline, romex, whatever, in the trench and are closing up, backfill about half full and drop in a run of bright colored surveyor tape in the trench and finish the backfill - then, if you (or someone else) is digging in the future you'll at least have a "heads-up" before you hit the goodies
     
  14. Beeman

    Beeman Well-Known Member

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    Just my opinion. I would run elect. conduit and use individual wires and not romex. I would also pull 4 wires so if you wanted 220 you could hook it up. I would also pull phone wire and possibly another set of wires in case you wanted to control something with a switch from the house. For the slight difference in cost it is always better to use a larger conduit so you can add wires later. I wouldn't use 10 ga. for that long of a run.
     
  15. I like the idea someone had to use surveyor's tape, but I wonder if the plastic will fall apart eventually. Perhaps you may wish to lay a steel wire (like barbless barb-wire--or Bob-wyre in Texas) near the top so you can find the line later using a metal detector.

    Since this project is only for a small shed, I think 10-3 romex (red, black, white, and a ground) should work fine. This will get you two 15 amp circuits and since the wire is oversized by two sizes, you should be fine at 300 feet for what little you need to run on the circuit. 14 gauge is normally used for 15 amps, 12 gauge for 20 amps, and 10 gauge for 30 amps, so I see no problem running 15 amps on 10 AWG. For crying out loud, we are only talking about a few light bulbs and a fence charger in a shed.

    I still think that plastic tubing and romex will be the easiest and fastest to install. (No joints of pipe to glue and only one cable to pull.) Personally, I don't like the idea of separate wires when a little more cost will get you the extra protection of direct burial romex. (It will still be a lot cheaper than the 8 gauge or heavier wire someone was advocating when saying 10 AWG was not heavy enough.) If you use large enough tubing you can pull in large wires in the future if necessary.

    You may wish to purchase a copy of "Wiring Simplified" at the electrical department of your building materials super store. This is a simple fairly comprehensive book. Worthwhile if you can find it. It is a small book about 6" by 8" and about a half inch or more thick. It is based on the latest national electric code. Don't waste your money on those fancy color books.

    Dale in Tx
     
  16. Beeman

    Beeman Well-Known Member

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    "For crying out loud, we are only talking about a few light bulbs and a fence charger in a shed."

    That's right now, We all have bigger dreams down the road. What happens when they add on the shed and wnt a welder and air compressor later. Easier to do it bigger now, but that's just my opinion.
     
  17. We really don't know the needs of "Bummer" though he only wanted 4 light bulbs and a fence charger. If I want a shed to park my riding lawn mower, I do not build a 60x120 foot barn. 6 and 8 Gauge cable is awful expensive just for 240 watts of light bulbs or about 2 amps plus a little more for the charger unless a MAJOR expansion is in the future. If the question were about a shop or barn or garage then I think perhaps a larger line is in order. Using tubing large enough for future expansion will allow pulling new wire for even the unplanned future enhancements. If a welder is in the future in the shed, then of course, wire for what might be conceivable, though for a welder, I would highly recommend a welder/generator so backup power were also available. A typical air compressor can still run on the 20Amp circuit.

    Bummer, by the way, what will the shed be used for??? Your planned usage (including future dreams) will dictate what you should use. I would concur with Beeman if you are planning on building a shop or garage near your shed or beyond your shed in the future.
    Dale in Tx