300ft run for power to shed?

[crabjoe]

I need to go as cheap as possible. LOL, who doesn't think like that these days when it comes to the price of wire.

What I want to do it get power to my shed. From the panel in the house, it's about 300ft. I'd love to have 120/240 there, but I can get by with 120.

Here's the issue. So far, everything I've tried to run, runs fine on an extension cord, but I'm being told, I need to install some super thick wire. Being that the extension cords are on 12 awg, why can't I get away with using something like 10-3 UF? Does the voltage drop that much?

BTW, what wire is used for a submersed 240v well pump?? Is it 10/3 or 8/3? I ask because my well pump is about 300ft from the panel, and it runs fine and I guess it meets code.

[HayZee518]

first of all the calculated voltage drop cannot be more than 3% per hundred feet. if you were to feed the shed I'd have to know what the anticipated load would be - what you intend to run from there. the feeder would need to be a four wire becaue a sub-panel has an isolated neutral, an equipment ground and two hots. as far as the well pump goes, the installation guys really don't follow a certain code they just run a triplex 12 and hope for the best. IMO for a well a 10/3 might do the trick but again you've got to consider voltage drop. sure the pump might work but you are lessening the life of the pump at a reduced voltage.

[crabjoe]

The biggest thing I expect to run is a table saw. I'm not sure what the amp draw is but it runs fine on a 15amp circuit. Other then that one item, nothings going to draw amps close to it, even my chop saw.

In the future, I might run a Mig welder, but even that's only rated to work on 120v/15amp. I figure 240v would be nice, but if need be, I'll get a generator to run anything that draws 20+ amps. Right now, I don't have anything that won't run on a 15 amp circuit.

Do you think it would be ok to just run 10/2 with a 20amp breaker at the house? This way I wouldn't need a sub panel.

[Speedy Petey]

The smallest I would go is #10.
10/3 will give you two 20A circuits. This would be a shared neutral circuit with two hots. If you have 120v loads running on both circuit this will actually lessen voltage drop.
Voltage drop is a convenience and design thing. Not a code requirement.
Without a known load you cannot know what the VD is going to be. With no load there is no VD.

[crabjoe]

I had a friend that does commercial work stop by yesterday. He was able to see the distance and for a single 20A circuit, he said I should be fine with 10/2, but nothing less. So I know now I can get by with 10/2 or 10/3 for 20amps.

So today I'm at Home Depot and look at wire pricing. I knew prices were high, but my jaw is on the floor!! This has got me thinking if I should just run aluminum. Maybe I should do 6-6-6-6 SER aluminum. I can't find it again, but I could have swore that it was available for 99 cents a foot. It was a place with in driving distance from me too.

[Speedy Petey]

SER is service cable. You do not want to run that in conduit, especially for that distance. The size conduit required, and extra work involved, would offset any savings you might see.


If you go the circuit route, as opposed to a sub-panel, DEFINITELY go with a MWBC (multi-wire branch circuit or shared neutral circuit <10/3 cable>).
For one extra conductor you will get an extra circuit, which will in turn help lessen voltage drop when both are being used as I said earlier.

[crabjoe]

Can't I just tun the Service cable without conduit then hook up a sub panel?

I'm thinking it would still cost less, maybe not much less, but having a sub panel would makes things a lot nicer. Plus, I found probably go 40amps with the service cable. This would mean I wouldn't need to worry about anything I might want to run.

BTW, do you think 4ft burial will be deep enough that I won't need to worry about anything other then digging for a swimming pool?

[Speedy Petey]

SER is NOT direct burial cable. In fact, I was thinking of USE when talking about running in a conduit system, not SER.

You would need USE or URD to run direct burial or in underground conduit. O you can use THWN individual conductors. Even then you need to protect the cable where it emerges from the ground or where subject to damage.

18" is deep enough for code. 24" is better.

[LazyPup]

As a plumber I will leave the wire sizing to the electrical experts however I am in full agreement with Speedy that I would prefer to see a PVC conduit and individual THWN conductors.

About a year ago I was working on a house sewer line from the structure to a septic tank. As I was digging the old sewer line up my shovel cut through the sheath of an unmarked buried cable running to a garden shed. When the shovel shorted out the wires it blew about an inch of the tip off my shovel and nearly caused me a heart attack.

Please, Please, Please, for the sake of us who make a living digging in the dirt, when you run a direct buried electrical service put it in conduit, and don't forget to run a "Red" marker tape indicating a buried electrical conductor.

You can get a roll of red plastic marker tape that is printed "Buried electrical line" at any good hardware or home supply center. Bury your line 18 or 24" deep, whatever your local code requires, then about a foot above the line lay a strip of the marker tape in the full length of the trench so that anyone digging in that area will hit the plastic tape first and be warned of the potential danger.

[crabjoe]

I'm going to bury this thing 4ft + deep because I'm going to run it near my property line and I plan on putting a fence up. I don't want to hit the line when I digging post holes. I'll make sure to put a Red marker above the line.

As for the wire, I might just go with 10/3 UF with ground. I found a roll of 250ft and the guys asking $150 for it. I can make up the other 50ft by running the line inside my house and putting a connection box on the outside for the 10/3 to connect to. This way I can run 8/3, inside, if that makes any difference.

Keep you're fingers crossed for me, that I get the 10/3.

BTW, anyone know how close I can run a waterline near the electric? I'd like to get water down at the shed too.

Thanks all!

[HayZee518]

if you are going to run 10/3, stick to 10/3 inside the house. don't go splicing 8/3 onto it. somewhere down the line the next guy's gonna see a double pole 30 breaker onthe 8/3 and may increase it to a double pole 40. in this case you'll be jeperodizing the 10/3

[crabjoe]

Here's another idea. with the 10/3, I won't have a sub panel at the shed. So now I'm thinking adding a sub panel on the other end of my house where the line to the shed will be. It would make things easier too because that's the side of my home where my current workshop is in the basement and I always need to put an outlet or what not in. In fact, I have to run a line for a water softener, so having a sub panel there would make it easier.

[HayZee518]

about the only reason you would have to put in a sub-panel is to make the "home runs" "shorter." or the need for more circuits than the 40 circuits in a main 200 amp (or higher) panel. I had wired a house in massachusetts that was 80 feet long and 50 feet wide. the main panel was in one corner of the basement. what that means is each home run back to the panel would have to be 80 plus feet. so the kitchen had a sub panel, the garage had a sub panel and the out-building had a sub-panel. any sub-panel feed is a four wire - isolated neutral and an auxillary ground bar inside. you could use a sub in your location with a #8/4 romex feeding it. would be protected by a double pole 40 breaker.