Running a 220v line to a shop

[SciFiJim]

What I don't know about 220 volt electricity could easily kill me. I don't even know what questions to ask. I want to build a shop in my back yard and wire it for both 220 and 110 volts. I know that I want a sub panel for those lines. I want to bury the line in a conduit. I don't currently have a use for the 220 but want to build for future need. What amperage should I be looking for. I assume a 110 line would be a 20 amp circuit. My question is, can a 220 line be split to run 110 circuits, or do I have to run separate lines for that? What amperage would I need for the 220 line?

edit to add - While I may eventually hire it done, I want to know what is going on so that I will know that truth and can detect BS.

[lylejb]

Ok. This is actually easier than it sounds. 220 is actually 2 110v lines, running in opposite phases. You can think of phases of a.c. like waves on the ocean, in that it's a wave that goes up and down. The trick with 220.is that one wave is going up, as the other is going down. The resulting difference is twice as much as either one by it's self. 110 is simply 1 of these phases as the hot, and a neutral 0 volt wire. The first question you need to plan for is how many amps you want to plan for. Its always advisable to wire for more than you think you will need.

Fortunately, there's a sort of sweet spot, cost wise, at 100 amps. That's what I did in my shop. I needed to run a 220v air compressor, as well as the usual 110v lights and outlets, and quickly found that I could put in 100A service for less than a smaller panel.

here's what I went with for a panel http://www.homedepot.com/p/Square-D-...PCVP/204836397

This panel kit provides a main shut off breaker, so you can be sure its off if you need to add to, or work on equipment. it comes with a few breakers, and plenty of room for future circuits. Basiclly, you could wire a house with this panel.

I run a 100A breaker in the main panel http://www.homedepot.com/p/Square-D-...00CP/100156187

Then run 2-2-2 aluminum triple wire to the panel. It's sold by the foot at the local home depot, and its way less than copper. About $1.50 a foot, or so. Its rated for underground service entrance (USE) so it can be direct buried.I did use pvc conduit from the panel to the bottom of the trench on both ends. The 3 wires are phase (hot), phase (hot), and neutral.

For ground, I drove a ground rod at the shop.

This might seem like more than you need, but you can connect almost anything, and it worked out to be the best value for me.

Hope this helps.

[Ickisrulz]

I have run power to two out buildings from my house. The digging and cable running is the hard part of the process and you only want to do it once.

I ran 100 amps to a sub panel in my workshop. This has the typical wood working equipment and I have plenty of power. I can't see going any less than 100 amps.

From the sub panel you just run the circuits you need. They can be either 240 or 120 of varying amperage depending on what you need.

You will need cable. I got mine from "wire and cable your way" which is much cheaper than local places. I used mobile home feeder cable (2-2-2-4) which is aluminum, good for 100 amps and can be direct buried. You will also need a 100 amp circuit breaker for your houses' breaker box and then a panel for your outbuilding. You will need to ground the box in your shop (driving 2 rods into the ground and connecting them to the sub panel with copper wire) and then connect the 4 cables from your "sub panel" to your main breaker box. It's not hard, but can be physically demanding.

(By the way, from what I understand if you need to run more than one circuit to an out building, you have to have a sub panel. But why wouldn't you if you are doing all that digging?)

[Duckiller]

Yes you can split 220 into 2-110. YES, HIRE IT DONE! Couple of years ago I put a 220 line into my garage. Table saw works much better. Joiner has power. Problem is I only put in one 220 outlet. Have to swap power cords. Put in several 220 and 110 outlets. Plus you need lots of lights. Allow for a good vacuum. I added a 200amp box to a 1956 era box. Now I have central air and a 30 amp outlet for my trailer plus the garage.

[rancher1913]

hundred amp sub panel at the minimum, and depending on distance you may need a ground rod or may be able to run the ground back to your main panel, you will need a local electrician to tel you which your code requires. bury the wire in conduit, its cheep insurance against future encounters. you can ask your local building inspector what he recommends then you will know for sure what will work for code in your area.

[Hickory]

If you're running this line any distance 60-70 feet you might want to invest in larger gauge wire, especially if operating equipment drawing a lot of amps.

[Ickisrulz]

hundred amp sub panel at the minimum, and depending on distance you may need a ground rod or may be able to run the ground back to your main panel, you will need a local electrician to tel you which your code requires. bury the wire in conduit, its cheep insurance against future encounters. you can ask your local building inspector what he recommends then you will know for sure what will work for code in your area.

These days when you install a sub panel, you have to use both grounding rods and run a ground cable back to your main panel. The code books have changed in the last 15-20? years.

[Plate plinker]

What I don't know about 220 volt electricity could easily kill me. I don't even know what questions to ask. I want to build a shop in my back yard and wire it for both 220 and 110 volts. I know that I want a sub panel for those lines. I want to bury the line in a conduit. I don't currently have a use for the 220 but want to build for future need. What amperage should I be looking for. I assume a 110 line would be a 20 amp circuit. My question is, can a 220 line be split to run 110 circuits, or do I have to run separate lines for that? What amperage would I need for the 220 line?

edit to add - While I may eventually hire it done, I want to know what is going on so that I will know that truth and can detect BS.

Two important questions are:
1- How many feet away will the new building be from the service panel?
2- How many amps do you require? Total of your needs. (saw?smelter?vacuum?)

Thats where you should start out.
Myself I would go large since it cost more to do it twice.

[454PB]

When I wired my shop, I put in a 200 amp service. I didn't really need that much, but the difference in cost was only about $200.

[Sweetpea]

You have had some good advice, it is not hard to do, but it will kill you if you don't respect it.

Yes, you do need to put a ground rod in, since it is detached from the house.

You do not need a separate ground rod for a subpanel in the same structure.

[Pinsnscrews]

Aluminum Wire is not acceptable in many locations by the Building Codes, so check with yours if your outbuilding has to be inspected.

[warpspeed]

The main panel to your house should be 220 V. Most newer houses have 200 AMP main service.

If you run a sub panel from the main it too will be 220 V. 100 AMP should be fine. I run all kinds of stuff with a 100 AMP panel in the garage.

The 220 V plugs will be 220 V as a function of the circuit breaker, pulling 110 of each leg as described so eloquently by lylejb. IIRC, mine are all 20 amp but that's a function of the tools that plug into them.

If you have an electric dryer or stove it will have 30 or 50 amp plugs, both of which are different.

Oh, and hire someone to do it.

[MaryB]

I went 60 amps, heaviest use will be the air compressor, maybe a small flux core wire feed welder. Since I am the only one who works in there only one power tool will be running at a time. Run your 220 to a breaker panel that is grounded as mentioned then you can add circuits using appropriate breakers. 120 volt breakers only plug into one phase and only have space for one wire(as long as it isn't a double breaker but only need those if you run out of panel space), 220 volt breakers will plug into both phases and have space for 2 wires.

[GL49]

Some good advice, some may lead you astray if misinterpreted. Best advice I've seen is "hire it done". You may be able to work with a contractor, you provide the parts and the ditch to their specifications, they come in, pull and terminate the wire. You'll save some money, and still have a safe installation that meets the requirements of the NEC. Yes, I am an electrician, teach electrical school, and been doing so for quite some time. Texas is one of the better states to live in when seeking qualified electrical personnel.

[farmerjim]

Go big. You can never have too much power. I have 300 amps at the house and 200 at the barn.

[Ickisrulz]

Aluminum Wire is not acceptable in many locations by the Building Codes, so check with yours if your outbuilding has to be inspected.

The NEC allows aluminum feeder cable (vs branch wires which is not allowed). So unless a city or town has some weird regulations, aluminum feeder cable is fine and seems to be preferred due to the cost savings over copper.

[rancher1913]

the responses so far show why I suggested you get with your local building inspector and go with his recommendations, different areas of the country do things differently, not wrong, just different codes they follow.

some areas aluminum wire is forbidden, some its blessed. some areas forbid the ground rod at the sub because of the difference of potential, some don't care about it.

[lightman]

Retired Sparky here. You've been give lots of good advice. Probably the best was "hire it done". Its not rocket science but it does require a little knowledge in the electrical field. My advice is to add up what you plan to put in the shop, add a % to that, measure the distance and calculate the service size and wire size. I'll help you with the wire size calculations if you want.

My shop is only about 20 ft from my house and I feed it with a 100 amp circuit. I can run whatever I want without problems. For what its worth, I like copper much better than aluminum. And I spent a lifetime installing and maintaining aluminum. If distance does not cause the cost to be prohibitive I would go with copper, in conduit.

[owejia]

Underground aluminum wire is not run in conduit so it can transfer the heat generated by the electricity flow out into the soil to keep it cool.

[Ickisrulz]

Underground aluminum wire is not run in conduit so it can transfer the heat generated by the electricity flow out into the soil to keep it cool.

Aluminum feeder cable can be run in a conduit.