Running electricity out to my garage (detached)

Reply

  #1  
Old 03-22-11, 08:49 PM
Member
Thread Starter
Join Date: Mar 2011
Location: USA
Posts: 4
Lightbulb Running electricity out to my garage (detached)

I am wanting to run wire and install electrical outlets in my garage. there will be a total of 5 outlets in my garage. The distance from the breaker box, through the attic and over to the garage is 93 feet. I am trying to find out if I should run 10/2 wire off of a 220v 30 amp breaker in the main box. and attach another box in the garage with the 110 outlets feeding off of it. does this sound right? and do any of you guys have any other ideas if not?
 
Sponsored Links
  #2  
Old 03-22-11, 09:28 PM
Member
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 175
You would need 10/3, because you need the nuetral for 120v. And its 240v not 220. The pro's on here will tell you more.
 
  #3  
Old 03-22-11, 09:36 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 32,659
am trying to find out if I should run 10/2 wire off of a 220v 30 amp breaker in the main box. and attach another box in the garage with the 110 outlets feeding off of it.
If you are just going to have 120v general purpose receptacles the breaker can not exceed 20 amps unless you use a subpanel. 10-2 wire could not be used to supply 120v circuits if attached to a 240v breaker because there would be no neutral.

Tell us your expected loads, elders, Compressors, Fixed tools like table saws? Electric heat, any need for 240v? Once weknow your needs we can better help you.

I'd suggest reading a book such as Wiring Simplified available at Home Depot, Amazon and other places so you better understand wiring.

Tech note: Nominal residential voltages are usually 120v and 240v ± 10%.
 
  #4  
Old 03-23-11, 06:02 AM
Member
Thread Starter
Join Date: Mar 2011
Location: USA
Posts: 4
I wont be running anything large in my garage. just a compressor and may have a drill press plugged in at some point. Other than that it will be general home items. maybe a space heater during the winter. I am just trying to figure out what wire and breakers I should get. If I were to run the 240 to my garage and in to another box there, I couldnt break it down to 110 outlets as needed?
 
  #5  
Old 03-23-11, 07:13 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,359
The subpanel installed would allow you to have the 120 volt circuits.
 
  #6  
Old 03-23-11, 07:13 AM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 32,659
If I were to run the 240 to my garage and in to another box there, I couldnt break it down to 110 outlets as needed?
No. You need 120/240v. A subpanel supplied with 3-conductor cable or individual conductors in conduit. Probably a 60 amp panel would be a good choice.

just a compressor and may have a drill press plugged in at some point. Other than that it will be general home items. maybe a space heater during the winter
Is the compressor 240v? What is its horsepower, amps on name plate. Same info for drill press and heater.
 
  #7  
Old 03-23-11, 09:20 AM
Member
Join Date: Oct 2005
Location: Milwaukee WI
Posts: 1,338
It sounds like you're doing this aerial (running to attic), but if not, trench in a conduit or suitable duct sized for the maximum reasonable usage in the garage, including whatever tools you want and 240V charger for electric auto. I'm guessing 1-1/4 or 1-1/2 but I am not an electrician. For 100 feet, your cost premium to put in a much larger conduit than needed is still pretty minimal.

Pull in whatever conductors meet code and your needs today, and know that if you need to upgrade in the future you can just pull in new conductors without trenching again.

Also run a parallel raceway for low-voltage.
 
  #8  
Old 03-23-11, 12:16 PM
Member
Thread Starter
Join Date: Mar 2011
Location: USA
Posts: 4
I will be running it through the attic. So I guess what I am trying to find out is what breaker I should buy for my current breaker box (there are 5 openings still, 2 on one side and 3 on the other) what size wire, and then of course what size breaker box and breakers in the garage for general purpose garage use. this is in a neighborhood so there wont be any huge loads happening
 
  #9  
Old 03-23-11, 12:42 PM
Justin Smith's Avatar
Member
Join Date: Dec 2010
Location: Cressona, Pa, USA
Posts: 2,546
For what you are saying, a 40A breaker and 8AWG wire should be sufficent with a 6/12 panel.
 
  #10  
Old 03-23-11, 02:55 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 32,659
My suggestion would be a 60 amp two pole breaker for your panel, a 100 amp breaker panel for your garage. The 100 amp panel with main breaker can often be bought with breakers for a lower price then some smaller panels.

If buried use 3/4" or 1" conduit and four #6 THWN wires. You'll need 1white, 1 green, and two blacks. Burial depth 18" minimum or use UF-b cable no conduit except for protection abobove ground burried at 24" minimum. Use a 50a breaker with UF.

If overhead use a 50a breaker and 6-3 sunlight resistant UF-b on a 1/4" steel messenger wire.

Just my guesstimate at 93 feet #8 on a 40a breaker might be pushing it a bit for the anticipated loads.

At the subpanel you will need to add a ground bar. You will also need to drive a ground rod.

Edit: When I suggested UF for overhead I was not aware you could get #6 aluminum qudplex. Use quadplex not UF. Simpler, better looking.
 

Last edited by ray2047; 03-25-11 at 06:28 AM.
  #11  
Old 03-23-11, 06:12 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,213
I will be running it through the attic
Does this mean you were wanting to run the power overhead?

If overhead use a 50a breaker and 6-3 sunlight resistant UF-b on a 1/4" steel messenger wire.
I like Ray's ideas except I don't like to see UF cable run overhead. I think I'd use Ray's ideas at both the house and garage, but I would connect the buildings overhead with aluminum quadplex, 3 insulated and 1 bare ground to support all 4 wires. #6 aluminum should be plenty big. Use a wedge clamp at each end and tie them to insulators lag screwed into the framing. You would need a 3/4" conduit with weatherhead stubbed out at both house and garage. Connect aluminum to copper using tin plated aluminum split bolts connectors with separators like these. Scroll to bottom of page C-36 at link below. Rubber tape and plastic tape connections on insulated conductors.

http://www.elecdirect.com/Data/ProductPDFs/C35-C36.pdf

This is a wedge clamp

Thomas & Betts W621-1 2 6 AWG Wedge Clamp

Use insulators like these.

Red Snap'r Small Lag Screw Insulator, White - 3600655 | Tractor Supply Company

Use Aluminum Quadplex like this.

Quadruplex Service Drop Aluminum Wire and Cable OneStopBuy.com

This will give you a professional looking service to your garage.
 
  #12  
Old 03-23-11, 07:48 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 32,659
I agree quadruplex is better but I didn't know they made it that small. Would not have suggested UF if I thought they did. Thanks for the correction.
 
  #13  
Old 03-23-11, 09:58 PM
Member
Join Date: Mar 2006
Location: NE Wis / Paris France{ In France for now }
Posts: 4,808
Ray.,

Belive or not the smallest quadplex overhead cable is 6.0mm˛ { #10 AWG } ACSR cable but 16mm˛ {#6 AWG } is far more common and most place will stock this size but few case you may have to order it ahead of the time { some may required X numbers of feet to get it otherwise electrical supply centre will have them on hand }

And the other thing you may want to keep in your mind I Know Quadplex 16mm˛ size they can use big as 60 amp breaker but in fact with North Americian side stay with 40 or 50 amp breaker the most and pay attetion when you make the splices between copper and alum conductors. this part you need to watch out otherwise it can fail rather quick if not heed it.

I use Polairs connector or IEIES* connector { Alum brick to use for connecting copper et alum conductors.}

And if you going overhead try to keep at least 12 feet or more clearance on low spot of span.

Merci.
Marc


* It is French verison of Polairs connectors which I get them all the time in Paris.
 
  #14  
Old 03-24-11, 05:46 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,213
Originally Posted by ray2047 View Post
I agree quadruplex is better but I didn't know they made it that small. Would not have suggested UF if I thought they did. Thanks for the correction.
The big box stores definitely won't stock quadplex and the accesories and some supply houses may not have it either. It may boil down to whether the OP has a supply house in his area that will order it for him if they don't stock it.
 
  #15  
Old 03-25-11, 06:16 AM
Member
Join Date: Oct 2005
Location: Milwaukee WI
Posts: 1,338
Originally Posted by heli.clay View Post
I will be running it through the attic.
Heh heh heh. I was inferring a detached garage. Never mind.
 
  #16  
Old 03-26-11, 06:54 AM
Member
Thread Starter
Join Date: Mar 2011
Location: USA
Posts: 4
My house has a detached garage, but it is still "attached" to the house via a covered walk way that goes through the porta cochere (Spelling?) the wire will not be exposed to the elements. It will go through the attick, through the covered breeze way, to the porta cochere, then back into the garage.
 
  #17  
Old 03-26-11, 07:33 AM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 32,659
Originally Posted by heli.clay View Post
My house has a detached garage, but it is still "attached" to the house via a covered walk way that goes through the porta cochere (Spelling?) the wire will not be exposed to the elements. It will go through the attick, through the covered breeze way, to the porta cochere, then back into the garage.
Then that totally changes what we have said. Where I am at least that is a common configuration and the garage is considered attached for code purposes. In that case it is optional to run a subpanel. You might want to talk to the local electrical inspection department and make sure it is considered attached.

If attached you can run separate cables for each load. If the breezeway attic is enclosed you can use NM-b. However I would still suggest a subpanel to keep it simple. However you can just use 3-6 NM-b from a 2 pole 60a breaker. No ground rod will be required at the subpanel but you will need a separate ground bar.

My answer is based on local practice where it is common to have the main panel in the garage and run all branch circuits through the breezeway attic to the house. Local code may vary.
 
  #18  
Old 03-26-11, 08:29 AM
Justin Smith's Avatar
Member
Join Date: Dec 2010
Location: Cressona, Pa, USA
Posts: 2,546
local practice where it is common to have the main panel in the garage and run all branch circuits through the breezeway attic to the house. Local code may vary.
That sounds messy and like a waste of wire.

In my area, the panel is usually located in the basement with a 2'' bored hole in the studs with all circuts branching off of that.

Anyway, I would do what ray suggested with the subpanel, and I would not run the individual circuts throught the breezeway. The subpanel looks more professional and workmanlike.
 
  #19  
Old 03-26-11, 09:05 AM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 32,659
In my area, the panel is usually located in the basement
Except for the first few years of my life I have never lived anywhere in the US that had homes with basements. Despite what some have explained to me about reasons for basements I still think it is odd and a bit dumb to spend money digging a deep hole under a house you are building. A hole that you have to exercise extra vigilance on to keep from filling with water. If you need extra space build up not down is what I say.
 
  #20  
Old 03-26-11, 11:12 AM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,374
I don't know about today but not that many years ago basement square footage was about 1/2 the cost of above-grade. The house I grew up in had a basement and it didn't fill up with water nor did it have a sump pump. There WAS for a short time a problem with rainwater running down the outside stairs, collecting at the bottom of the stairwell and coming under the door but that was easily solved by placing a diversion "speed bump" at the top of the stairs.

Basements, at least the ones below grade CAN be usable living space with far less problems of heating and/or cooling than above grade spaces.

Quite honestly, I wish I had a basement in my present house.
 
  #21  
Old 03-27-11, 08:23 PM
Member
Join Date: Oct 2005
Location: Milwaukee WI
Posts: 1,338
Originally Posted by heli.clay View Post
My house has a detached garage, but it is still "attached" to the house via a covered walk way that goes through the porte-cochere the wire will not be exposed to the elements. It will go through the attic, through the covered breeze way, to the porte-cochere, then back into the garage.
This is a good example of how semantics can be not just relevant but critical in appropriately solving a problem.

I don't know the textbook definitions, but if there is continuous structure between the garage and the dwelling, through which utilities can pass without direct burial, raceway or exposure to the elements, in my book, it's attached, not detached.

This may approximate the underwriter's definition, under which you pay more for insurance with an attached garage than a detached garage. With a detached garage, when the garage starts burning, there is less chance of the fire spreading to the house since the fire would have to cross x feet of open ground to reach the house. If the two are bridged by any structure, without some type of firebreak, it's easy for fire to pass from one to the other.

Obviously there are interval gradations, but your garage is only detached in the sense that you have to walk outside your house before you get inside your garage. On the other hand, my garage is detached in that plus the fact that it is separate from the main house by at least 15 feet of concrete, rock, and lawn.
 
  #22  
Old 03-29-11, 09:10 AM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,295
Originally Posted by ray2047 View Post
I still think it is odd and a bit dumb to spend money digging a deep hole under a house you are building.
Most places up here in the great frozen north you need to dig a 48" foundation to get beneath the frost line anyway, and once you've dug a hole that deep it's only a couple more hours on the excavator and a few more yards of concrete to have a full basement so the additional cost isn't too much compared to what you have to do anyway.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
'