Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 09-21-2011, 09:49 PM   #1
Newbie
 
Join Date: Sep 2011
Posts: 4
Share |
Default

Updating wiring for detached garage question


I just bought an older home and just figured out the garage shares a 15amp circuit with 4 bedrooms and the laundry room.

The house has 125amp service.

My goal: is to get 30amps to the garage and have a 240v receptacle for a future welder, lathe, compressor, etc. And some 120v 15 and 20 amp receptacles and over head lights.

I can easily run a new line from the main to the garage subpanel through the crawl space/attic of the home. The main panel is about 50 feet from the garage plus factor in another 20misc feet.

My plan: Is to purchase a 30amp double pole breaker, (for the main) and then run 8/3 romex.

My question: Is this a good start? I'd like to make sure, that I can run a 240v line then take it back down to 120 with various 15amp and 20amp breakers.

inlet510 is offline   Reply With Quote
Old 09-21-2011, 10:33 PM   #2
Electrical Contractor
 
kbsparky's Avatar
 
Join Date: Sep 2008
Location: Delmarva
Posts: 3,361
Default

Updating wiring for detached garage question


You'll need a small sub-panel for the garage.

With #8/3 romex, you should be able to use a 40 Amp breaker in your main panel.

From the new sub-panel, run your circuits for the outlets and lighting on separate breakers.

__________________
-KB

Life is uncertain -- eat dessert first!!
kbsparky is offline   Reply With Quote
Old 09-21-2011, 11:49 PM   #3
JOATMON
 
ddawg16's Avatar
 
Join Date: Aug 2011
Location: S. California
Posts: 6,836
Default

Updating wiring for detached garage question


Quote:
Originally Posted by kbsparky View Post
You'll need a small sub-panel for the garage.

With #8/3 romex, you should be able to use a 40 Amp breaker in your main panel.

From the new sub-panel, run your circuits for the outlets and lighting on separate breakers.
Ditto.......

Just make sure you don't have more than 6 breakers in the sub.....and do not tie the ground and neutral together in that sub panel....

Some juristdictions would also require a ground rod at the garage.
__________________
"The dream is free but the hustle is sold separately."

My 2-Story Addition Build in Progress Link ... My Garage Build Link and My Jeep Build Link
ddawg16 is online now   Reply With Quote
Old 09-23-2011, 11:03 AM   #4
Newbie
 
Join Date: Sep 2011
Posts: 4
Default

Updating wiring for detached garage question


If I ran 30amps, could I run 10/3? Or would that be pushing it? A book I have says to factor in some buffer room, but at the same time the cable should already have that engineered into it right? Theres never going to be a constant 30amp load, it may get up to 27 for a few seconds at a time.

I'm trying to save some money but at the same time be safe.

Also what type of wire do I use for the short overhead run from the house to the garage? UF rated wire?
inlet510 is offline   Reply With Quote
Old 09-23-2011, 12:31 PM   #5
Licensed electrician
 
Join Date: Sep 2007
Location: Maryland
Posts: 7,409
Default

Updating wiring for detached garage question


Is the garage attached or detached?
__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
Jim Port is online now   Reply With Quote
Old 09-23-2011, 12:32 PM   #6
Member
 
Code05's Avatar
 
Join Date: May 2009
Location: Easton MD
Posts: 1,841
Default

Updating wiring for detached garage question


Quote:
Originally Posted by inlet510 View Post
If I ran 30amps, could I run 10/3? Or would that be pushing it? A book I have says to factor in some buffer room, but at the same time the cable should already have that engineered into it right? Theres never going to be a constant 30amp load, it may get up to 27 for a few seconds at a time.

I'm trying to save some money but at the same time be safe.

Also what type of wire do I use for the short overhead run from the house to the garage? UF rated wire?
You can use 10/3 UF on a 30 amp breaker if you support it independently with a messenger cable.

Since you going to a residential garage, which is subject to vehicular traffic, a minimum height of 12' is needed for the entire span.
Code05 is offline   Reply With Quote
Old 09-23-2011, 12:36 PM   #7
Member
 
Code05's Avatar
 
Join Date: May 2009
Location: Easton MD
Posts: 1,841
Default

Updating wiring for detached garage question


Quote:
Originally Posted by Jim Port View Post
Is the garage attached or detached?
Title says detached. Who knows?
Code05 is offline   Reply With Quote
Old 09-23-2011, 12:40 PM   #8
Member
 
Code05's Avatar
 
Join Date: May 2009
Location: Easton MD
Posts: 1,841
Default

Updating wiring for detached garage question


Quote:
Originally Posted by ddawg16 View Post

Just make sure you don't have more than 6 breakers in the sub.....and do not tie the ground and neutral together in that sub panel....
Unless there is a main breaker or disconnect.

Quote:
Some juristdictions would also require a ground rod at the garage.
Never heard of one that did not for a sub- panel and two is the norm.
Code05 is offline   Reply With Quote
Old 09-23-2011, 12:48 PM   #9
Licensed electrician
 
Join Date: Sep 2007
Location: Maryland
Posts: 7,409
Default

Updating wiring for detached garage question


Quote:
Originally Posted by Code05 View Post
Title says detached. Who knows?
This was the part that raised the question.

Quote:
I can easily run a new line from the main to the garage subpanel through the crawl space/attic of the home. The main panel is about 50 feet from the garage plus factor in another 20misc feet.
__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
Jim Port is online now   Reply With Quote
Old 09-23-2011, 12:51 PM   #10
Member
 
Code05's Avatar
 
Join Date: May 2009
Location: Easton MD
Posts: 1,841
Default

Updating wiring for detached garage question


Quote:
Originally Posted by Jim Port View Post
This was the part that raised the question.
Gotcha, I missed that.
Code05 is offline   Reply With Quote
Old 09-23-2011, 01:49 PM   #11
A "Handy Husband"
 
rjniles's Avatar
 
Join Date: Feb 2007
Location: South Carolina Low Country
Posts: 3,942
Default

Updating wiring for detached garage question


Quote:
Originally Posted by Code05 View Post
Never heard of one that did not for a sub- panel and two is the norm.
Canada CEC apparently does not require ground rods for a sub panel in an outbuilding. OP does not list his location.
__________________
Location:
Coastal South Carolina
rjniles is offline   Reply With Quote
Old 09-23-2011, 02:02 PM   #12
Newbie
 
Join Date: Sep 2011
Posts: 4
Default

Updating wiring for detached garage question


To clarify, the garage is detached, I would be running the wire through the home to the back of the home where the original wire drops down from the 2nd story to the garage so clearance isn't a problem.

I do know about the ground rod and will be picking up 2? My question is what type of wire do I use for the transition from the home to the garage.

Attached is a pic, I'm in California you can tell by the sun in my illustration.

inlet510 is offline   Reply With Quote
Old 09-23-2011, 02:08 PM   #13
JOATMON
 
ddawg16's Avatar
 
Join Date: Aug 2011
Location: S. California
Posts: 6,836
Default

Updating wiring for detached garage question


Quote:
Originally Posted by Code05 View Post
Unless there is a main breaker or disconnect.
Correct....forgot to put that in.....ask me how I found out.......

Quote:
Never heard of one that did not for a sub- panel and two is the norm.
Quote:
Originally Posted by rjniles View Post
Canada CEC apparently does not require ground rods for a sub panel in an outbuilding. OP does not list his location.
That has been a topic of disccusion over on the garage forum I'm on.....believe it or not, there are some parts of the country who do not require/enforce it....

Some say, if you have a sub in your house, there is no way to install ground rods in addition to what you already have...hence, why would a detached garage need ground rods as long as you run the ground from your main to the sub.....

Of course, there is a big difference between a sub in your house and a detached garage some distance from the house.
__________________
"The dream is free but the hustle is sold separately."

My 2-Story Addition Build in Progress Link ... My Garage Build Link and My Jeep Build Link
ddawg16 is online now   Reply With Quote
Old 09-23-2011, 02:22 PM   #14
Member
 
Code05's Avatar
 
Join Date: May 2009
Location: Easton MD
Posts: 1,841
Default

Updating wiring for detached garage question


Quote:
Originally Posted by ddawg16 View Post
Correct....forgot to put that in.....ask me how I found out.......





That has been a topic of disccusion over on the garage forum I'm on.....believe it or not, there are some parts of the country who do not require/enforce it....

Some say, if you have a sub in your house, there is no way to install ground rods in addition to what you already have...hence, why would a detached garage need ground rods as long as you run the ground from your main to the sub.....

Of course, there is a big difference between a sub in your house and a detached garage some distance from the house.
You can add as many rods as you like to a house, they just cannot substitute as an EGC.

Code05 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Questions regarding wiring 220 to attached garage... John Green Electrical 0 01-20-2011 09:23 AM
garage / bedroom wiring code question 205bhamjim Electrical 4 01-20-2010 09:55 AM
Garage Heater Wiring ceiling penetration Question DenverBob Electrical 5 12-28-2009 01:01 PM
Detached Garage Load Question andyjk1 Electrical 14 10-19-2009 02:32 PM
Garage - Protecting wiring installation eastment Electrical 4 11-26-2005 11:52 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.