# Running Electricity to the garage



## guest

im planning a garage for this spring/summer.. before i can do it, i need more excavation/fill.. so while i have a dozer her, i plan to have him tip his blade and have a trench dug to run electricity from the house to the garage.. 

I plan to put a condiut in prior to the slab being poured.. 

I am looking to get wire, 
do you think outdoor SER 100 AMP is sufficient?


i want something strong enough that i can run a compressor or various power tools. i plan to put a small electrical box out there too.. The other draws of electric; garage openers (some day), lights, power tools, table saw... 



The distance will be about 50 Ft from the house so ill put the wire in 1.5" pvc as its under the driveway... 


anything else i should be thinking of?


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## Greg

120 & 240? How many amps. 

How about running a water line (PVC) so you can have water/sink etc.

Gas line for a Heater?

Do you have a generator? How about a dedicated line back to the house to connect to a transfer switch?

Telephone extension line or an intercom for the garage?

Line for a security system?

Do you have a compressor? How about a pipe for air to the house for whatever you want to clean near the house?

Lots of possibilities. Think of them all now before you cover it up.

Greg


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## guest

Greg:
Not sure about amps 220 i think?

The compressor is a 120 plug style if thats what you mean... 


Water is tough for the garage.. we are on well and septic so no easy way to get water in or out- access to the septic.. 

intercom good idea Id probably do cordless walkie talkies so i could call in for a beer... 

Phone: cordless or cell

The generator is a good thought.. but so far weve been here going on 6 years and have only had 2 power outages so i have no generator. 

Heat: im going to put a wood stove in there... someday..


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## Fusion1970

That would be way cool to build a garage from the ground up, while doing everything you want. Good ideas mentioned. About the only other thing I could think of is a 4" water drain in the center of each bay. 

Good luck,
Greg no. 2


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## jodyand

Well I'm no electrician so i cant tell you what size wire to use but if it was me i would have a 200amp breaker box just so if you ever need it for a welder or bigger air compressor.
Jody


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## archyb2

S J
Mayby you could just bury 3 or 4 conduits,maybe even a larger one, with a small nylon cord in each one, they would always be there, you never know what you might want to do 5 yrs down the road and the cord would let you pull whatever through there at a later date.

Archie


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## farmallmaniac

That air hose one is a very good idea as is the 3-4 conuits 
Ryan


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## Ingersoll444

If you can at all swing it, a 220V line would be best. You may not need it now, but when some one walks up to you, and gives you that "awsome deal, that I just could not pass up" on a nice sized compressure, or welder, you will wish you had one. And with out a doupt run more then one tube. That stuff is cheap, and agean, you just never know.


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## Chipmaker

As long as your opening up a trench to lay a power feed I would also lay in a larger PVC line say a 4" just in case you ever want to pull any other type lines through it. Don't know if any particular codes will apply to you in your area, but around here its not uncommon for folks to bury regular white 4" PVC and use it to pull wire and such through later on. I used to have my air compressor in my shop thats attached to the house, and it was always very noisy, so I relocated it out in the shed about 80 feet away, and plumbed the air line into the shop, now its quiet, and the place stays much cooler during summer months as well. I am hoping to relocate my large rotary phase converter to the shed this summer, and get rid of that high heat and noise source as well. 


As for a panel box, I would put a 200 amp panel box in as a minimum as someone already suggested. You do not have to supply it right off with 200 amps, but its much easier when the time comes you need more power to already have the right sized panel box installed. If you check around you may be fortunate enough to scrounge up drops of UF type wire for free or next to nothing. I have a friend that runs underground feeds for a company and when the rolls of cable get down to under 100 feet or so, they toss the remaining cable, so I can easily get most any size wire I need for free. Its direct burial and requires no conduit.

So all I need right now is a few more feet of cable so I can run a man made generated three phase circuit iin addition to a regualr 200 amp service to my foundry shed and out buildings. No such thing as too many amps in an electrical service.


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## guest

good info...

I think the 100 amp wire will support 220 volts right? 
im not an electrician.. but i agree i would want it to be able to handle 220v just in case...


good ideas thanks 

i like the drain idea... i will look into what it takes to do that....

seeing as this will be only a 4" slab.. i wonder if 1.5" conduit or a 4"drain pipe would weaken the slab?

i planned to use a 1.5" conduit for the electric run.. 
but its a good idea to add an extra or use a bigger conduit pipe for future use... I could add an extra 4" pipe run and cap the ends and bury it for future use...


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## dougand3

The gauge of the wire determines how many amps it will safely carry. Even small 14 gauge romex cable (your lights, small appliances, many of your duplex outlets) will handle 600 volts BUT only 15 amps.

12 gauge = 20 amps

10 gauge = 30 amps (your 220volt water heater).
Look at your water heater and notice the romex wire going into it....that is 220volt and probably 10 gauge and 30amp.

A big cable (I don't now their designation) to handle 100 amps will surely handle 220v.


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## Chipmaker

Well if you want a full 200 amp availability you will have to go with 2/0 wire as its the minimum size rated to carry a 200 amp load. However just when do you really think you will ever pull a full 200 amp load. To run it you would have to subfeed off your house entrance panel, awith a trough and a fused disconnect or breaker. Ihave an Ampacity chart on my website that lists the sizes of wire according to amperage draw or load capacity. Its on the Technical stuff page, and towards the bottom, titled AMPACITY CHART.

Its usually more the capacity of the breaker box in the amount of breakers you caninstall for various circuits, that comes into play more so than actual amperage load, so thats why its best to go with a larger 200 amp box with more breaker capacity, even if you only install a 100 amp service feed. Short of having a 50 or 60 amp draw on a electric welder running full out, and perhaps a couple of plug in electric heaters goping, and a 20 amp air compressor running full out 100 amps is a lot of juice. I have a #4 wire feeding a 30amp fuse type box in my foundry shed, and it handles a 20 amp air compressor, lights, fan, radio and a wood lathe or chop saw as well as a 2 hp sand muller. Just not all at the same time.


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## Greg

*Ramblings...*

SJ,

I agree with Chipmaker on the 200A breaker box. You will need to bring in electricity from your service box at the house, so I would go with the same size wire, thick but safe. You might also consider a lockable breaker switch to the garage feed right at your service entrance so you can turn off the whole garage, if ever necessary, right from the house. I would run your AC conduit separate from any other wiring conduit. You just might get AC "buzz" on any other cables/wires you run to the garage if you have them together.

Your service feed will bring in 2 120VAC wires, a ground and a neutral. Each has it's function, and neutral is NOT the same as ground. Neutral will be the "return line" and ground, usually an unsheathed copper wire connect to a copper rod driven into the ground for shock protection.

For your 120VAC circuits, you use one 120VAC line from the feed for those. The 2 lines are connected to opposite sides of your breaker box terminals so you will have capacity for multiple 120VAC circuits.

For 220VAC you will use the 2 120VAC wires to give you 240VAC. So you will have the already have the ability to use 220.

I would run a multiple wire "telephone" wire to the garage. You can use it for a telephone, intercom, alarm, or other low voltage use.

If you have cable or satellite TV, run a cable to the garage for a TV there.

Outlets:

Outlets are like "toys"... you can never have too many! Figure out how many you think you need...then double it! 

You will need sockets for your garage door opener(s) in the ceiling near where the motor will be located. You need outlets just inside the garage doors so you can plug in tools you will use outside without have to string extension cords across the garage floor.

How about your work bench? You need lots so you are not plugging in and out cords when you switch tools. 

Are you going to put in permanent florescent lights in the ceiling, or hanging units? You need outlets for them. How about outside lights? How about a ceiling fan for circulating the air, especially if you put in a wood stove.

Assuming you are going to insulate the garage, be sure to have all these in first. Check your electrical code for location. Some have specs for how far off the ground the have to be, etc..

I would NOT run the conduits under the concrete! Run them to the side of the garage, then inside. If you have a problem, you do not want to have to break up the floor. 

Water/Drain:

Installing a drain in each bay is a great idea. Do it now! When I installed a drain system in my yard last year I ran 3 perforated PVC pipes from the yard, brought them together will "Y" adaptors and ran them to one of the lowest place in the front yard. I then dug a pit about 4' wide x 5" long x 5' deep. I filled it with large gravel it works well and would handle the amount of water from your drains. Be sure to slope it. 

You will need water to "wash down" whatever, so might as well run it other places too. You might want to put in a small apartment size refrigerator for a "cold one", snacks etc. If you pick up a used full size, you could connect up the ice-maker! Beats running back and forth to the house. You can also get a small RV sink, and be able to wash-up or clear your eyes if you do something dumb. Again, don't run the pipes under the concrete. An outside faucet is handy for gardening work or pressure washer. Much better than dragging hoses.

Enough for now. Take what you like, ignore the rest.

Greg

P.S. you can pick up a good "basic home wiring" book, from Sunset Homes, at your local hardware or book sore. Remember, electricity can kill. Have your wiring inspected by a licensed electrician BEFORE you finally connect up anything. You can do most of it yourself, but get final approval by an electrician. And remember, whatever amps you use in the garage and the house, will come out of your home service entrance capacity. If you don't have enough capacity coming in, you will have to increase you service capacity.


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## Chipmaker

> _Originally posted by simple_john _
> *good info...
> 
> I think the 100 amp wire will support 220 volts right?
> im not an electrician.. but i agree i would want it to be able to handle 220v just in case...
> 
> 
> good ideas thanks
> 
> i like the drain idea... i will look into what it takes to do that....
> 
> seeing as this will be only a 4" slab.. i wonder if 1.5" conduit or a 4"drain pipe would weaken the slab?
> 
> i planned to use a 1.5" conduit for the electric run..
> but its a good idea to add an extra or use a bigger conduit pipe for future use... I could add an extra 4" pipe run and cap the ends and bury it for future use... *


Seems like some have AMPS and Volts mixed up. AMps is the pressure or force the voltage flows with through a conductor. Volts is the amount of flow. Look at amps like a water hose. A smaller diameter hose will carry less water than a hose with a larger diameter. The larger the wire (or hose) the less resistence there is, so on a hose it will not make the hose sidewalls be as hard and on a wire it will not have as much heat build up from resitance. It normally takes 2 wires (no ground is needed to make 220VAC) and a pair of wires as thin as the hair on yur head is more than capable of carrying a voltage of 220 volts or even 600 volts. It matters not, but what matters is the resistence it encounters when you put a load on it and it tries to supply the demand, those hair thick wires will not carry any amount of amperage, but it will carry all the volts you want. Back in the late 20's and 30's houses were wired with what was called knob and tube. MOst had a set of wires (one hot one neutral for a total of 120 volts) running though them that you just tapped off where you wanted a light etc. Then they went to a 60 amp service when appliances etc started to come into their age.......and the need for 220 i a house was born. 60 amp was the standard basic 220 volt supply for houses for quite some time. It then went to a 100 and later to 125 and then 150, and now today 200 is about the minimum for most dwellings. Granted most folks shops and garages do not need a full 200 amps of power, even my garage shop is subfed with a 100 amp box (lack of room and I had the box and breakers already) and it supplys my welders, lathe, DRO's powerfeeds etc, milling machine, rotary phase convertor, all my plug in power tools like drills and angle grinders, heat guns and lights, and also all my bench tuype tools like 4 belt and stone grinders, drill presses etc. It also subfeeds my foundry shed, all off thatone 100 amp box. The only things that may be running in conjunctio with each other wold be a welder and compressor or a compressor and power tools. YOu need to figure up what your amperage use at any given time would be and add 40% or so to it, so you have a bit of margin, and go with that wire size. For the most part lights and garage door openers and small hand held power tolls do not draw all that many amps. But another thing you need to take into consideration is line loss with the distance that the electrical wires have to run from the house to the garages / sheds panel box. I would not see having any problems with a 1/0 size wire or larger running at the distances you mention, but you need a pretty close distance measurement and figure in your line loss. Yo actually get more line loss in underground wiring thanyou do in aerial drop wire, as it cannot dissipate any heat buildup as quickly, hard as that may seem to belive but dirt is not a good conductor of heat buildup as air is. You shold be able to get wire of sufficient gage for direct burial for under $3.00 a foot that will power most anything most folks would ever hook up to it.

You only need two wires or conductors to obtain 220 volts, but for safety you need a ground wire as well, but most if not all 220 volt items will run with 2 wires. SOme areas electrical codes require the addition of a forth conductor, and its classed as a neutral. About all that wil not work on just two wires is if the idem has any 110 /115 volts items light a indicator light etc.....as they require a neutral or ground to function. I do not recomend using just two wires, but at one time this was the way it was done. See what your code in the area requires 3 or 4 and go with that.


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## Greg

> "AMps is the pressure or force the voltage flows with through a conductor. Volts is the amount of flow."


Sorry, Chipmaker, but I believe you have it reversed. Volts is the pressure and Amps is the current flow. 

Appliances are usually rated in the Amps, current flow, they draw at 120V or 220V.

If you have an Amp meter on your tractor, it measures the current flow at 12 Volts. Many battery chargers have multiple Amp settings for the same 12 Volt. Mine has 2A, 20A and 60A settings.

Greg


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## guest

Thanks for the info guys.. 
I got 1.5" pvc yesterday and 75 ft of this SER 100 amp wire.. its big thick stuff so that should do the trick.. (t was expensive 1.12/foot.. and its not outdoor wire so i needed to put it in pvc (which i planned to do anyway) 

Then upon further thinking, i went back to home depot today and got 100 ft of TV cable and phone line and 1/2" pvc to run those in.. now with the amenities in there.. ill have to fight to keep my family from moving in above the garage... unch: 

still thinking about doing a drain pipe.. want to talk to the excavator to see where/if i would want to run the drain pipe to..


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## dougand3

While you're running cable, don't forget cat5 or cat5e network cable if you have cable or DSL internet. Mighty handy for looking up info on parts while out in the shed/garage. Good for Fing Off, too. 100' with RJ45 connectors is ~$12.


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