Running Power and Water to Barn

Thanks for all the input so far everyone.

I'm basing my wire sizes on these online calculators like here:
http://www.csgnetwork.com/voltagedropcalc.html
but they seem to vary a bit. Does anyone know how to do the actual calculation manually? When I plug in my situation for the 2ga wire at 320 feet I get a 3.6% drop which sounds acceptable to me. I believe code requires 5% or 3% depending on situation so that seemed close enough. Most of the time it'll be loaded much less than 50 amps too.

I think I understand the grounding. I believe the rule is that a 3-wire service is allowed when there are no other metallic connections between the structures, and you have to install two grounding rods at the remote panel. It treats it just like a separate service essentially.

I did find a better deal locally on the #2 aluminum direct bury triplex at $0.97/ft, so maybe I can go that route after all. Anything in copper over #10 gets so expensive I might as well go to aluminum wire.

I'm struggling to see what the problem with running them in the same trench is. With the water table here, the wire is going to be under water most of the time anyway, so I don't see what having a water pipe close would hurt. I understand it would have to be hand dug to repair a problem due to them both being close, but all I've got is a shovel anyway. I am going to be renting a trencher to install so I guess running a second trench would not be that big of a deal.

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Their other calculator
http://www.csgnetwork.com/wiresizecalc.html
says you need 1/0
If you want 50 amps out there anytime you need the right sized wire. Ever run an electric weedeater on 150 foot of 16 gage wire....it makes the smoke come out. Use anything with solenoids? low voltage makes the smoke come out. Improper sized wire causes problems. Do it right or don't do it at all.

That's why there are professionals that do this day in and day out. That's why codes were invented.
Even if you don't use a pro, it would behoove you to contact one so that can learn what it takes to get the job done properly and up to code for your area.
Cheap is good but safe is better.

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On the resistance of wires and why a welder could be a problem. The resistance charts are great as far as they go, but they are based on wire at a standard temperature. When you run a large current through a wire, the voltage drop is because of resistance, and resistance heats the wire. Not only is excessive heat damaging to insulation, but a physically hot wire has more resistance than a cold one. When wire is above ground in mid-air, that might not be an issue. When it is underground in an enclosed space, that heat can build up and melt through insulation. With motors and a lot of other items, when voltage drops, there is a compensation that occurs because the amperage increases. That exacerbates the problem. Power companies routinely run massive amounts of power over small wires at high voltage because the current is proportionately lower. If power was distributed at 120 volts (as Edison tried to do) the wires would have to be massive, and they would be physically hot much of the time from line loss.

The problem with high current load gets worse if you have a junction that is enclosed. Junctions corrode and have increased resistance. Our home in Florida was within days of burning up when I was sniffed an odd odor out back and discovered that the meter box was too hot to touch. When the electrician came out, we found the insulation on the wires from the meter to the breaker box had become so hot that it had turned to scraps of carbon. The two hot legs were within an eighth of an inch of creating a dead short that throwing a breaker would have no effect on.

When you run a welder, do you turn on a light? Do you need a fan if it gets too hot? Once a line is in place it is all to easy to forget the limited capacity, and people who visit or later buy the property might have no clue that wiring isn't up to snuff. If you run small gauge wire, put the appropriate circuit breaker on it and don't try to run high amperage equipment.

On conduit and replacing wires. I learned the hard way that this sometimes doesn't work the way you expect. I had a nice 110' length of 4/0 x 3 + ground that I installed in underground conduit. When the home was placed, I discovered that I needed 120' and that splices were not an option here. I hooked the cable to a rope to the trailer hitch of my van, and very neatly stripped the insulation off one side, where it was pressing against a 1' radius curve in the conduit and the joint snapped from the force. I was not happy, since I had planned on re-using that for wiring to a shop. If you plan on replacing wire in conduit, use long sweeps, have runs of no more than 100 feet, and use plenty of lubricant.

Put 4" of Styrofoam insulation over the pipe before filling the trench.

Jim

run your wire and pipe through plastic field tile. easy to pull it out of the end if you need to put in new pipe or wires. also keeps the rocks and the frost off it

Harry that's interesting about the conduit. So for my 320 foot run it is worth it to bother with the conduit or will it give me so much trouble pulling the wire that I shouldn't bother. It's not exactly a straight path either, there would be some curves necessary. I guess if it's hard to pull out it will also be hard to pull in. I certianly would not want to damage the wire trying to pull it, I can't afford to buy it twice.

Will my welder work okay if I run the proper wire which I guess is 1/0 aluminum for 50 amps? Or will it not work at all at that distance. I have to believe it will work if I use the proper wire. Looking at some of these other calculators I see that the first one I used seems to be undersizing for some reason... I guess you get what you pay for eh?

Jim, that's a good idea to put styrofoam above the wire where it crosses the drive, I can do that for sure.

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When you start dealing with long runs like that, things start to get weird. I have a couple of 1/4 hp pumps that I use to pump water from our creek. One of them sits at the end of a 100' extension cord and works fine. The other, down by the creek, is at the end of 250' of extension cord. On a good day, with the wind blowing right, and the moon in the proper phase, that lower pump will start up fine. Most of the time I have to go down there, remove the bell housing and spin the cooling fan to get it started.

I think what you may want me to say is that your welder will probably be OK. I can't do that. My guess (and this is just a guess) is that under load the voltage will drop from 120 to maybe 100 or 95 volts. That means everything on that circuit will be operating under brownout conditions. Some stuff can handle it, some stuff can't.

When you put wire in a conduit of that length, you generally don't pull it all the way. You uncoil the wire and lay it alongside the trench, then slide a section of conduit over it to the middle of the run, slide another and join it, and so on down one half of the run, then you repeat the process on the other side and when finished drop the conduit in the trench. When I installed our conduit, the power company mandated that I put in an above ground junction box about 150' away from the pole. My guess is that they have figured out the distance that they can safely pull wire if it needs replacement.

All I can do here is relate real-world experience. I'm not very comfortable with some of the suggestions you are getting or the direction your heading, so I think I'll bow out of the thread at this time and just hope that I don't get to say "I told you so." Before leaving, I do have a suggestion though, when you get your cable, run it on the ground and try out the load at the other end before burying the cable. Use a voltmeter to measure the real voltage. If it anything less than 105, you are likely to run into problems with at least some equipment.

(FWIW, the pig on the pole that services your house has various taps. If the power company has a long run to your entrance, they select a tap with a slightly higher voltage to compensate. That is why they can safely have long runs at 120/240)

BTW styrofoam bead board will load up with water, destroying insulating qualities, and will quickly crush under load. (One devious way to keep drivers from parking on a swale when they ignore the signs is to drive long nails into a thin board, push beadboard over the nail shafts and bury the thing just under the sod, with the nails pointing up. People can walk over it safely, but a car or truck will crush the foam and puncture the tire. Don't do this, as it could hurt someone if you missed replacing a crushed one. I'm just illustrating the properties of beadboard in a way that you will remember.)

You mean insulation over the pipe, not the wire. You can just go a foot deeper by the road & it will be fine. Or use insulation, but use the right type - special colors & cost more for use under ground. Don't waste time with the cheap stuff.


Same with your wiring. Is the point to have a good useable safe electrical box out at the remote site, or is the goal to spend as little as possible? You don't get the same results from those 2 goals.

I think they use 3% drop for feeder lines as you are running, assuming the juntion box & more wiring in the end building will consume another 2% on average. If you are laying down a feed line that already uses 5% voltage drop, then any other wiring or extention cords will drop you well below 5%.....

So, if you use the right wiring, yes you can use a welder out there.

So many on here only look at dollar signs. If you want enough power to run a welder out that far, you simpley have to use the right materials to get that amount of power out that far.

Plastic tile & other types of 'conduit' are not actually allowed by code - you are supposed to use electrical conduit to run electric lines in. Why? I donno. But that is code, and while some parts of code seem to be spliting hairs, other parts are based on decades of observation & experience & safety.

I'm not smart enough to know which is which.

--->Paul

I'm not a smart electrical or pipe person but when I had to run a water line under the driveway I took an old heavy duty lead pipe from the junk pile and ran the line through it under the driveway. It has been over 8 years and nary a leak yet. It was a 10 foot section of drain pipe from when the house was replumbed. Recycle. Have a good one.

Paul,

I'm very aware of the do it cheap vs. do it once argument. My situation is that I can really only afford to do it cheap, but I'd like to do it right even if I have to stretch the budget to do so. #2 direct buried Aluminum I might be able to swing, but 1/0 or 2/0 is going to be out of the question. So if #2 is really not going to be enough to be useful, I might as well just get some #12 extension cords to get a light and water heater working for now and forget about running a real feeder out there. At least I can use the extension cords elsewhere if I do get a real feeder put in later.

I've gotten some very good candid feedback here and I appreciate that. Basically that my idea of using #2 for 50A service will not work, I can get maybe 35A on a #2. If I give up the idea of running a big welder out there, maybe that's enough. Or maybe I should wait a year and see if I can afford bigger wire next year. I'll still have to think about that. I guess I was hoping that someone would say voltage drop on the 50A #2 feed will be okay, maybe the lights might flicker but it'll work. Guess that's not the case from what everyone is saying.

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cfabe, you dont need to run the black water line through any thing i have a line on my farm that's been in since 1953 and its still working fine. it would be worth checking with the power company about getting them to put power to your barn. i have a well that's about that far from the house and it cost $13 month for the service. and if any thing ever goes wrong with the wire they fix it, the easement is nothing i dont know why people worry about that, its for your use not anyone else. they cant just hook onto it and go to another place without your approval and they will never be back unless something happens to it and needs fixing.

We wanted drinking water and electric back in our little park. I don't remember if it was 6-800 feet from the house. Pump water from the pond to the back garden and orchard, Power for the airstream trailer and possibly a visiting motorhome and who knows? The water, I regret now, is seasonal. I haven't finished it yet but I should have put in a couple of hydrants.

I assume within code, because it was recommended by a relative that works for the power company, I direct buried
00 aluminum underground feed. 3 individual wires ...1 common and 2 can be 110-115. I used a copper ground rod back there for the ground.

I also put in phone cable just in case.
Now that we're where we are, I wonder if I should have put in a cable for the computer.

Brain damaged.... I also don't remember exactly but some of it I put a steel rod through the lower links of the 3 pt on the little Kubota and through the spool, and then drove and fed it into the trench