Questions on burying power and water

[PorkyCat]

Hi All,
I've got a barn about 110' from the house that has its electricity provided by overhead wire from the house to the barn (where there is a panel).
I'd like to put that wire underground and need advice on doing so. Like, should I/can I bury PVC pipe and use the existing wire. If so, what size? How deep? I'd like to run a water line to the barn as well. Can I use the the same trench? Any tips or ideas would be appreciated.
I've rented a mini excavator tomorrow to dig out some stumps and thought I might have some time left over for trench work. So I'm all ears. Thanks!

 

[Kubotasrking]

A couple links for you:
T8-6 Underground Burial of Belden Cable
IEEE (electrical) Code Issues - Burying PVC conduit

I do not think overhead cable and underground feeder cable have the same outer layer insulating from water. I think you will need new cable, buy many others will likely have the 100% sure answer.

I wouldn't place them in the same trench because of potential future issues such as repair. You will have to repair both after excavating to get to the issue...

Best of luck!

 

[SPIKER]

Porky:

sorry not enough information to answer you. where is the barn wire feed comming from? the meter or inside the house from a circuit breaker panel?

what size wire is it? generally FLY wire (which is usually what is suspended has a cable along with the wires, and tends to slightly chafe the wire insulation after a while blowing about. you need to know what size the existing wire is what kind of shape it is in, (end to end full inspection) hate to burry something and have it go bad shortly there after or even before getting it in. also after bakeing in the sun & heated by electrical current it may have very damaged insulation...

you can buy dirrect burrial wire pretty cheaply and no need for conduit if it is already protected by breakers someplace... anyhow more info can help...

mark M

 

[PorkyCat]

Good questions. The wire is actaully coming from a breaker box in the house, not a meter. The overhead wire does have a cable with it. I don't know the size of the wire. I'll have to check that. I hear what you're saying about not wanting to bury it and have it go bad. I'll look into the direct burial wire. Can you tell me likely sources of supply or name brands?
My main concern for tomorrow is to figure out if I need to dig a seperate trench for the power line and water pipe while I have the excavator on hand. Can you advise on that?
Thanks!

 

[_RaT_]

Good questions. The wire is actaully coming from a breaker box in the house, not a meter. The overhead wire does have a cable with it. I don't know the size of the wire. I'll have to check that. I hear what you're saying about not wanting to bury it and have it go bad. I'll look into the direct burial wire. Can you tell me likely sources of supply or name brands?
My main concern for tomorrow is to figure out if I need to dig a seperate trench for the power line and water pipe while I have the excavator on hand. Can you advise on that?
Thanks!

Consider conduit. It provides great protection from critters and backfill and allows easy installation when done correctly. Buying THHN wire is also a nice way to go, it has great current carrying ability and pulls nbicely. I am just finishing up a run in 1.5" PVC conduit with 3 #4 cu wires and a #8 ground wire. The breaker is 70 amps. Depending on the size you need, Lowes or Home Depot may carry what you need. I just did a post about the lousy service at HD and Lowes in the wire dept. You need them to cut the stuff for you. Remember to, a spool of wire gets a considerable discount over cut wire. Good luck. Remember a conduit for phone and other low voltage needs.

 

[OakHillFarmer]

I hope I'm not too late.

You can't bury electrical and water in the same trench. At least not here in MA. Plus, the water must be below the frost line which varies by region. Here, a water line is a 4' bury and electrical is a 2' bury.

Good luck!

 

[CurlyDave]

I'd like to put that wire underground and need advice on doing so. Like, should I/can I bury PVC pipe and use the existing wire. If so, what size? How deep? I'd like to run a water line to the barn as well. Can I use the the same trench? Any tips or ideas would be appreciated.

I've rented a mini excavator tomorrow to dig out some stumps and thought I might have some time left over for trench work. So I'm all ears. Thanks!

You need to fill out your profile, so we know where you are -- don't be shy.

My power company (Pacific Power in OR) says explicitly: "The customer may be able to place signal and other electrical conductors in the same trench as Power Company conductors...

"The Power Company will not install electrical conductors in a common trench with non-electric utilities, such as water, sewer and other drainage lines..."

Now your line is not a power company line, but I suspect these guys know a lot more about it than any of us.

I would be inclined to put the water line in a separate trench, call the power company for trench separation distances.

I would not burry used overhead wire.

 

[RonMar]

Direct burial wire will probably be the easiest. The size wire will depend on the electrical load. What size breaker is the overhead line on now and what will you be running in the barn? The only place I have ever seen water and electric in the same trench is the line typically run to the well head for a domestic well.

 

[gotrocks]

"Code or No Code". Back in the '60s I put pvc water and 3 (#6) alum wire in same hand dug trench from house to barn/shop. We had a thunderstorm (with lightening) one afternoon. Lightening hit a pecan tree in the back yard that is approx 20 feet from the trench. The "charge" went down the tree and I guess through the roots to the trench, it ruptured the pvc water line and burned ONE of the wires into. Also traveled into shop and house. Destroyed a couple of breakers (one in each location) and also a couple of switches on tools in shop. Water leak located the damage. Dug down and spliced both and ALL IS WELL. (At least it still works.)

 

[anthonyk]

You'll DEFINITELY want to put it in some sort of conduit.
If you're ever doing some sort of yard work, or running sprinkler lines, whatever, and you put a shove through your buried wire, you could be in for a real surprise. Use conduit, preferrably steel. It's worth the money.
I buried my own telephone cables from the street to the house, about 2 and a half to 3 feet deep, and dang if I didn't cut them myself while planting some trees. Imagine if I'd cut into a nice 120 vac line instead. It would have been adios amigos.

good luck,

anthony