Power to barn

[Jasper]

I am looking for advice regarding running power from my house panel to a barn appoximately 120' from the house service. Some have suggested direct bury cable and some would prefer conduit. I would require sufficient power to run 8 to 10 fluorescent lights and support running small electrical tools and a table saw drawing up to 20 amps.
Any and all suggestions are appreciated.

Jasper

 

[sal64]

hello my barn is 140ft from house i ran gray wire 8 or 10 gage cant remember buried 6 inches i run 5 8ft florecent lights 5 gal air compresor with no problems.i no it isnt to code in my area supose to run it in conduit but i wish i ran 220 so i can run a welder mite do that in future .

 

[Gilford]

Greetings. I had a similar project a few years ago, but wanted a 100 amp service in the shed which is probably 200' from the house. I used #2 copper and put it in 2" conduit. I rented a trencher to make the trench. As I glued the conduit togetner, I inserted rope inside so I could pull the wire through later. I have 16 flourescent light fixtures and often have 3 220v machines running at the same time, there has never been a shortage of power available. Other members will have good suggestions too, but this worked out good for me, no regrets.

 

[studor]

Look at 3acres thread in this forum with same title last week -- most of the advice will apply (I think even the distance is about the same)

 

[jamesa]

I jsut ran a 90 amp service to my shop/barn #2 trailer wire in 1 1/2 . 220 feet put it 2-3' deep would have gone 3' on all of it but we have some water lines in teh 3-4 range.

#2 al is good for 100amp but with drop ill get about 90amps plenty for my 50 amp welder adn 80 amp plasma cutter.

I would put a 50 amp service in at a min if you plan on runing anything but lights

10/3 is good for 30 amps if your only doing lights.

8/3 50 amps less drop for distance

 

[valley]

Hi Jasper, I did close to what you plan last November. I laid plastic coated armored with 10-2 to the small barn. I did put in a sub panel at the house but not at the barn. I have freeze protected water buckets 5 light and several power outlets. It isn't a problem to use a drill or saw out there or a small heater for an animal giving birth in winter. The plastic coated armored is from a house I just wired, given me by the owner, or I would have used PVC. If I were going to put in a table saw and a welder, that type of thing, then I would go to #8 and a sub panel at the barn a sub panel is always convenient. Hope this helps. Richard

 

[Lineman North Florida]

Whatever size wire you decide to use ,do yourself a favor and put it in c onduit, eventually direct buried wire gets nicked during installation and it will burn out causing you to try and find the bad spot and dig up the yard to fix it. Make yourself a rat out of a plastic bag tie a string to it and take your shop vac and put it on the other end and it will suck the bag along with your string in and you are ready to pull your wire in. Hope this info helps.

 

[DTCOOPER]

James,
Not sure where you calculated your wire size.. To get 100amps with aluminum conductors, at 220', you'll need 2/0 wire.. This is based on 3% max voltage drop..
About 58 amps is all you'll get reliably out of #2 aluminum at that distance, in conduit.
check out this link.... Voltage Drop Calculator

 

[buckeyefarmer]

James,
Not sure where you calculated your wire size.. To get 100amps with aluminum conductors, at 220', you'll need 2/0 wire.. This is based on 3% max voltage drop..
About 58 amps is all you'll get reliably out of #2 aluminum at that distance, in conduit.
check out this link.... Voltage Drop Calculator

Not sure I fully trust that calculator. When I put in copper, it will use 60C ratings for the wire, and not 75C or 90C. That makes a big difference. Also the PF makes a huge difference. for most lights, not an issue, for motor loads it can be.
For AL, I would use 2/0 as 2AWG is only rated 90A @ 75C, non adjusted for drop. Should ask the inspector first, his answer is the right one.

 

[ScottK]

I used 10/2 romex (it was much less expensive than separate conductors at Home Depot by some fluke of pricing) and put it inside 3/4 inch pvc conduit 2 feet deep. I laid the romex out straight and then slid the conduit over it as I glued it together and then dragged the whole thing and dropped it in the trench with some helpers (aka kids). Even when I have used outdoor (direct burial) cable, I still put it inside conduit to protect it. The conduit is really cheap insurance. I say don't waste money on the direct burial stuff and get the best deal you can on whatever is available and put it inside pvc conduit.

 

[hydrovane218]

I second scottk's advice. A couple of years ago, I built a 2 1/2 car garage about 20' off to the side of the house. I ran a 60a sub panel in the garage off the house's 200a panel. I ran NMU 6/3 loomex cable(direct buriel rated)and for extra safety/piece of mind, I put it in 3/4 PVC conduit. I ran 3 wire(plus ground) cable since I wanted 230v for my compressor and welder and it worked great.
My 2 cents would be to go the same NMU cable(in your case, 10/2 should be plenty, especially given no major motor loads or a welder) and put it in PVC conduit also.
Good Luck

 

[Inspector507]

If anyone is doing this in an area that is subject to inspections by the local regulatory agency, you need to check what they are looking for. Type NM cable is not permitted to be run outdoors or underground. Not even in any type of conduit.

 

[nhkabotab7800]

i vote for conduit...i ran a new direct bury wire to my pool after the existing wire got hit somewhere while new leach field was being installed....two years later tree between pool and house hit by lighting, and you guessed it wire fried....only now i have a pool deck over the area the wire needs to be run....well it turned out to be a great excusse to but a backhoe and dig a trench and burry conduit.... just my story....in case you were wondering

the backhoe sure is fun though

 

[MikeInEburg]

I Just want to reiterate what Inspector507 said - NM type cable (Romex) is REALLY not appropriate in outdoor applications - even in conduit. The jacket is just not made to be immersed in water - and that is what will happen in many conduits - mostly due to condensation. Saving a couple of dollars today is usually not worth the safety and service life risks.
Mike

 

[Lineman North Florida]

You say you only want to power a few lights and a table saw, that is now, your needs can change drastically in say 10 years. If you went ahead and buried you some inch and a half or better yet 2 inch conduit you could still go with the romex and when your needs change you have the capability to upgrade your wire size to suit your new needs. I can't tell you how many friends I have helped go back and re-do what we could have done right the first time. No matter what you decide conduit is the only way to go, your kid's will thank you for it one day.

 

[Gomez]

I would run #6 copper, (NOT ROMEX, as stated Romex is not rated for underground/outdoor applications) to a 60amp subpanel in the garage.

 

[tglass]

I agree with DTCOOPER, run the double ought wire in conduit. The sting of the extra cost will be easy to get over sleeping good at night, and adding anything like a welder later won't be much of a headache. Whatever you do, don't forget to run lines like telephone, tv cable, remote light switch from the house. Not to admit I did.

 

[Lineman North Florida]

ROMEX TYPE UFB!!! Suitable for direct burial in outdoor applications. as written on manufacters box it came in Colonial cable company, power companies have been doing it for years.

 

[Inspector507]

UF-B is listed for use underground and outdoors. Nothing wrong with that. NM-B aka Romex is not.

 

[Cat_Driver]

The advantage of trenching to your barn is that you can think of other options in the trench.

Example, you can add a security line from the house to barn so if someone breaks in you get a signal in the house. OR, a video cable to add a camera, how about a light switch at the house so you can turn on the outside lights of the barn from the house.

The options are endless when trenching and using conduit rather that just dropping direct burial cable in the dirt.

Take you time, think out many options and always go bigger cable than needed for either future or to keep the cable cooler.

Copper in my opinion is the only way to go.

I ran a 600 ft cable and added a video cable conduit, and a phone cable conduit all at the same time. Years later I was glad I did because I was able to easily add video monitoring because of break ins, and the phone conduit was big enough to add a 25 pair cable for phones, internet, and securoty.

It was cheaper doing it with an open trench than digging another trench while trying to miss the original conduit later on.