10/ 3 wire ??

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I am going about 150 feet to a shed, and plan to run number 10 gauge wire. This is simply a shed, and I want to be able to run power tools and have some lights in the shed. I plan to use UF wire, and of course go 2 feet underground.
Someone advised to run 10/3 instead of 10/2, but I forgot the reason why. It seems they were indicating I could have TWO circuits instead of one. Is that correct ? If so, then it seems that I could have 2 separate 20 amp circuits, but I am not sure.
When we say 10/3 wire, is that two main live wires, and one common ground ??
Thanks a lot !!
--James --
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Yes, 10/3 will give you two circuits, or one circuit and a spare. It is good for 30 amps, so would be fine to connector to 20 amp breakers

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Thanks to Ralph and RBM for these informative answers !!
--james--
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RBM wrote:

You can have several circuits if you run it to a small breaker panel in the shed which is what I'd recommend.
Matt
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No, not two singles, you MUST connect to a single- 240 volt breaker (opens both legs of the ungrounded conductors simultaneously). Run to a larger outlet box and split both circuits off from there, one for recepts and one for lights.
If it's a fairly long run, I would go along with RBM and set overcurrent at 20 amps (to account for voltage drop).
With 12/3 you could run about 125 ft (from circuit origin to shed) with a 3% voltage drop (about 8 volts) at 240 volts (another reason to use 240 out to the shed instead of 120). With 10/3 you could run about 200 ft (assuming the same 16 ampere load, gives about 8 volts voltage drop.)
Dennis

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>> >> >>>I am going about 150 feet to a shed, and plan to run number 10 gage >>>wire. >>>This is simply a shed, and I want to be able to run power tools and have >>>some lights in the shed. I plan to use UF wire, and of course go 2 >>>feet underground. >>> >>>Someone advised to run 10/3 instead of 10/2, but I forgot the reason >>>why. It seems they were indicating I could have TWO circuits instead >>>of one. Is that correct ? If so, then it seems that I could have 2 >>>separate 20 amp circuits, but I am not sure. >>> >>> >>>When we say 10/3 wire, is that two main live wires, and one common >>>ground ?? >>> >>>Thanks a lot !! >>> >>>--James -- >>>

If the circuit is to be split into two separate circuits, without two or more ungrounded current carrying conductors terminating on the same yoke or strap, and the installation is governed by the US National Electric Code (NEC), then there is no requirement to use a two pole breaker unless the circuit will supply 240 volt loads.
Some will argue very forcefully that it is good practice but I disagree. A double pole breaker will open both circuits on a fault or overload thus plunging the entire building served into darkness because a saw hung up in a piece of paneling for instance.
Separate buildings always need a building disconnecting means. On residential property this can take the form of a common snap switch or set of three way switches in each ungrounded conductor. Better practice is to use a double pole switch that will open both ungrounded conductors simultaneously. Best practice would be to use a disconnect that is listed for use service equipment which would be required if it were not residential property.
--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
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Along that line I'd suggest using a 30amp breaker at the house, to protect the feed wire from over current, and a small panel in the outbuilding, with some 20 amp breakers for the local circuits.
Then you can have multiple circuits in the building, preventing what you fear, everything going dark on a fault. And you don't have to go back inside the house to reset the circuit.
And you can have specialty circuits with different over current protections if you need to protect a specific device.
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When you specify 10/3 wire, you normally get a cable with 4 wires in it. There will be a black,red,white, and an uninsulated wire. The best way to wire it is to connect the black and red wires to the breaker box so that you have 230 volts across them and the white wire is the neutral. There will be 115 volts from the white wire to the black wire and also to the red wire. The bare wire is the ground and it might be referred to as the green wire. Number 10 wire is good for 30 amps, but if you are running it 150 feet and try to use the full 30 amps the voltage drop may be too much.. Try to ballance the load on the two circuits if you can. This is not always possiable while using differant tools. You could put the lights on one circuit that you don't use much and use the other one for the tools.
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Hi James,
As always, check with local authorities; however, in Canada you can run multiple hots with a single neutral as long as you use seperate phases.
Be careful!
Justin
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They have electricity in Canada??!!
DAMN!
Next thing you know you'll have indoor plumming!
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Yup, we even got telephones without wires and 'puters and funny colored money.
It is tricky to run the 'lectric heaters in our igloos, you have to keep turning them off so the ice can harden up again.
We have a 12 lane highway, but you have to watch out for the 18 wheel snowmobiles, they think they own the road.

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lol!
Wood stoves in ice fishing shantys can be a challenge!
Kidding aside though, knew a guy on Lake Champlain near Canada that had a wood stove in his along with TV, sofa, chairs and then some. This was not a typical shanty. Occasionally they drilled a hole and fished by accident when they got drunk enough.
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wrote:

I'ts sometimes difficult, but important, in igloos and ice shanties, to keep the wood dry. If you don't do this, you may woodecute yourself.

Remove NOPSAM to email me. Please let me know if you have posted also.
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wrote:

with 10/3 went to a shop and split into two 20 amp circuits at a subpanel.
My advice, run two. I ran mine thinking I would just use a few tools and lights. Shop developed into something bigger with several 220 volt machines. I had to run another line out.
Frank
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10awg is the minimum size that you can run and legally use as a feeder to a subpanel. (minimum feeder size is 30 amps).
If you know you are going to have larger loads than just lights and outlets, rather than running a second line, run larger wire.
Instead of running UF cable, I would run (2) PVC conduits, one for power, and one for communications. I would make them a minimum of 2" diameter, maybe 3" for power. Allow for expansion, once the conduit is in the ground, it's easier to pull new wire, than replace the conduit or buried cable.
For a 150' run, I would go up at least one gauge to allow for voltage drop, and go up at least one gauge above your intended load to allow for expansion. That would mean #6, which is rated for 50 amps, would be my suggested minimum, allowing for a 40 amp subpanel, with allowance for some voltage drop. Since it is in conduit, you will be pulling individual wires, not UF cable.
You will probably want to pull some phone and CATV cabling in the other conduit. Just remember that any cabling in underground conduits needs to be waterproof, and should be considered to be under water.
--
-- Welcome My Son, Welcome To The Machine --
Bob Vaughan | techie @ tantivy.net |
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James wrote:

You can run also 220 and 110 both if you use the third conductor as a neutral. This would require you to have a separate grounding rod at the shed. I'm not up on the latest code and I believe it has changed as to when you may or may not use a ground rod at an outbuilding like this. I'd check with a local inspector or electrician who is familiar with the current code.
Matt
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Oddly enough, we mean two hots, one common, and one ground. total of four wires.
Red and black are hot, and white is neutral and bare is ground.
--

Christopher A. Young
You can\'t shout down a troll.
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wrote:

Don't confuse this any more than you have to. Feed it from a 2 pole 20a breaker in the house and use GFCI receptacles in a 4" square box as soon as it gets ointo the shed. Feed 12/2 to the rest of the down stream outlets connected to the "load" side of the GFCI.
If you put another sub panel out there you kick a whole other can of worms, ground rods etc. This "multi-wire" circuit is just ONE circuit in NEC speak so your life is easier. You can still tap off of the "line" side of the GFCI with both phases to feed 240 volt outlets.
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wrote:

Yes, and that way you also have 220 access for something like a 220 air compressor motor. Of course if you even plan to get a welder and use it in there, go to #6 - 3 wire.
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