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 11-16-2011, 08:27 AM   #1
Member
 
Join Date: Mar 2011
Location: San Jose, CA
Posts: 35
Rewards Points: 25
Question

Re-running 120 to my garage - want to do it right


Hello

When I bought my house, there were 6 copper wires strung in the air between my house and the separated garage. The insulation was cracked and copper was exposed. First thing I did was shut off the main, cut those wires down, and cap the ends.

I want to run 2 x 20 amp lines to my garage underground using conduit. It's about a 20 foot run that goes under a cement path in one spot, and does not run under any auto thruway of any kind (no road or driveway). I have 2 20 amp slots allocated on my breaker panel for the runs, and I can easily string them under my house to the point of exit to the garage.

A few questions:

- If I want to run data lines or phone lines, how far apart does the separate conduit need to be, and can it be above the electrical conduit? (electric is 24" down, can data be 18" in the same trench?)

- Should I install new ground bars and a sub-panel for just 2 circuits? Or is it better just to run romex to a junction box at the point of exit and then single strand in the conduit for the 2 lines?

- Any other suggestions before I get started?

spdorsey is offline   Reply With Quote
Old 11-16-2011, 09:52 AM   #2
Member
 
Join Date: Nov 2011
Posts: 48
Rewards Points: 25
Default

Re-running 120 to my garage - want to do it right


- If I want to run data lines or phone lines, how far apart does the separate conduit need to be, and can it be above the electrical conduit? (electric is 24" down, can data be 18" in the same trench?)

As long as you put them in separate conduits you can have them in the same trench.

- Should I install new ground bars and a sub-panel for just 2 circuits? Or is it better just to run romex to a junction box at the point of exit and then single strand in the conduit for the 2 lines?

I would just use a j box. No need for a sub for 2 circuits.

Colomboj is offline   Reply With Quote
Old 11-16-2011, 10:22 AM   #3
Member
 
Join Date: Jun 2007
Posts: 3,508
Rewards Points: 2,004
Default

Re-running 120 to my garage - want to do it right


Good job on removing the existing mess overhead.
But you cannot do what you propose. You cannot run more than one branch circuit or one feeder to any structure on your property.

NEC Article 225.30 States.
II. More Than One Building or Other Structure
225.30 Number of Supplies. Where more than one building
or other structure is on the same property and under
single management, each additional building or other structure
that is served by a branch circuit or feeder on the load
side of the service disconnecting means shall be supplied
by only one feeder or branch circuit unless permitted in
225.30(A) through (E). For the purpose of this section, a
multiwire branch circuit shall be considered a single circuit.

So this leaves you with three options. A feeder and sub panel. A single branch circuit or a MWBC (multiwire branch circuit).
Searching this forum using the keywords I have used will explain each option in detail.

Running data cables between the two structures is a good idea and should be run in the same trench with the power conductors. Conduit for each is the very best way to go.
Research your three options and when you decide which one you will use, we can assist further if required. If you do the research, you will need no more assistance. This subject has been beat to death 100's of times on this forum. Good Luck.
J. V. is offline   Reply With Quote
The Following 3 Users Say Thank You to J. V. For This Useful Post:
HARRY304E (11-18-2011), Jim Port (11-16-2011), spdorsey (11-18-2011)
Old 11-16-2011, 10:35 AM   #4
liscenced electrician
 
Join Date: Jul 2008
Location: Oregon coast
Posts: 983
Rewards Points: 500
Default

Re-running 120 to my garage - want to do it right


Pipe it from your electrical panel into a sub panel. Run individual conductors. You need 2 hot wires. A nuetral and a ground. You also need to drive ground rods. If I was going though the effort, I would run a minimum of #10 and a 1" pvc conduit. Low voltage just needs to be shielded cables but it isn't a bad idea to try to put a little space in between the 2 conduits.
jimmy21 is online now   Reply With Quote
Old 11-16-2011, 12:26 PM   #5
Retired from the grind
 
gregzoll's Avatar
 
Join Date: Dec 2006
Location: Midwest - Central Illinois
Posts: 14,271
Rewards Points: 2,204
Default

Re-running 120 to my garage - want to do it right


If all you are wanting in there is 120v/20a to power a light and a outlet for the garage door opener, you can get away with #12/2. If wanting more, so that you can run a welder, shop tools, etc, then I would look at maybe a 240v/60a circuit. The later will require a sub=panel, the other would not need a sub, since the breaker in the house would serve as the disconnect.
__________________
Ren: Now listen, Cadet. I've got a job for you. See this button? Ren: Don't touch it! It's the History Eraser button, you fool! Stimpy: So what'll happen? Ren: That's just it. We don't know. Maybe something bad, maybe something good. I guess we'll never know, 'cause you're going to guard it. You won't touch it, will you?
gregzoll is online now   Reply With Quote
Old 11-16-2011, 02:29 PM   #6
Member
 
Join Date: Aug 2011
Posts: 90
Rewards Points: 75
Default

Re-running 120 to my garage - want to do it right


I concur with the subpanel option. I would run a larger size wire (#8 or #6) to allow a future upgrade to 30 or even 50 amp service in the garage. Run 240v with three wires plus ground. On the garage subpanel, you can have two circuits (or more if you buy a bigger box). Install the ground rods. Do not bond the neutral to the ground in the subpanel. Of course, use a double breaker in the main box.

I would run a separate conduit for the communication cables, and I would just bury both at 24".
brgmgb is offline   Reply With Quote
Old 11-16-2011, 02:55 PM   #7
Retired from the grind
 
gregzoll's Avatar
 
Join Date: Dec 2006
Location: Midwest - Central Illinois
Posts: 14,271
Rewards Points: 2,204
Default

Re-running 120 to my garage - want to do it right


They could also use "Octopus" cable for the com. That would give them two data (cat-5e or cat-6), two rg-6, and a cat-3. It would have to be the "flooded" jacketed type for use through the conduit. Reason being, is that moisture would play havoc on the cabling, which can happen in conduits.

http://search.yahoo.com/search;_ylt=...param=&rd=pref
__________________
Ren: Now listen, Cadet. I've got a job for you. See this button? Ren: Don't touch it! It's the History Eraser button, you fool! Stimpy: So what'll happen? Ren: That's just it. We don't know. Maybe something bad, maybe something good. I guess we'll never know, 'cause you're going to guard it. You won't touch it, will you?

Last edited by gregzoll; 11-16-2011 at 03:03 PM.
gregzoll is online now   Reply With Quote
Old 11-16-2011, 03:07 PM   #8
liscenced electrician
 
Join Date: Jul 2008
Location: Oregon coast
Posts: 983
Rewards Points: 500
Default

Re-running 120 to my garage - want to do it right


Quote:
Originally Posted by gregzoll View Post
the other would not need a sub, since the breaker in the house would serve as the disconnect.
I think you mean over current protection. The garage would still need a disconnect. The way i do it is mount a 4 square box up high, at say 72" and put a commercial grade 20a light switch in. and label the cover. With it up that high, it won't get confused for a light switch, and if anyone ever wants to put a sub panel in, it gives plenty of room to cut the pipe off and mount a sub panel. Also, if only using #12. Still use 1" so that larger wire could be pulled in later
jimmy21 is online now   Reply With Quote
The Following User Says Thank You to jimmy21 For This Useful Post:
spdorsey (11-18-2011)
Old 11-16-2011, 03:36 PM   #9
Retired from the grind
 
gregzoll's Avatar
 
Join Date: Dec 2006
Location: Midwest - Central Illinois
Posts: 14,271
Rewards Points: 2,204
Default

Re-running 120 to my garage - want to do it right


That is how I would do it, keep things simple.
__________________
Ren: Now listen, Cadet. I've got a job for you. See this button? Ren: Don't touch it! It's the History Eraser button, you fool! Stimpy: So what'll happen? Ren: That's just it. We don't know. Maybe something bad, maybe something good. I guess we'll never know, 'cause you're going to guard it. You won't touch it, will you?
gregzoll is online now   Reply With Quote
Old 11-18-2011, 08:51 AM   #10
Member
 
Join Date: Mar 2011
Location: San Jose, CA
Posts: 35
Rewards Points: 25
Default

Re-running 120 to my garage - want to do it right


J.V. - Thanks for the code snippet - that answers a few questions. I have a clearer idea of what to do. When we bought the house, it had 3 structures in the backyard (the yard is 85' deep), and 2 of them had electric running to them. We tore down all except the garage, but none have elec right now. Perhaps we are grandfathered in because 2 structures had elec before? (just a shot in the dark).

Jimmy and Greg - I'd LOVE to run a 50 amp circuit to the garage, but I'm pushing the service as it is (I have 100 amp service). I just ran wire and new outlets/switches throughout the entire house and rewired much of the breaker box from knob/tube to romex. There is one spot left in the panel, and I can afford a 20/20 double breaker for the garage without overloading the house - just barely.

I may be upgrading my service sometime soon. Ugh!

The garage will be a "man cave" of sorts - containing a computer, TV, fridge, and a small photo studio. I will also use power tools in there, but not very often at all.

The replies are fantastic and very helpful. I appreciate all of them.
spdorsey is offline   Reply With Quote
Old 11-18-2011, 09:19 AM   #11
Member
 
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 6,964
Rewards Points: 2,024
Default

Re-running 120 to my garage - want to do it right


You can run the #6 wire (for 50 amps) to the garage now and for the time being, power it with the 20/20 double breaker. Later when you or someone else upgrades the main panel and service you can give it the full 50 amps.
__________________
Forget super sized fries. The Washington Redskins could promote healthy eating with First Lady Obama by choosing a (red skinned) turnip for a mascot.
AllanJ is offline   Reply With Quote
Old 11-18-2011, 09:37 AM   #12
Retired from the grind
 
gregzoll's Avatar
 
Join Date: Dec 2006
Location: Midwest - Central Illinois
Posts: 14,271
Rewards Points: 2,204
Default

Re-running 120 to my garage - want to do it right


spdorsey, only would you overload, is if your home is all electric.
__________________
Ren: Now listen, Cadet. I've got a job for you. See this button? Ren: Don't touch it! It's the History Eraser button, you fool! Stimpy: So what'll happen? Ren: That's just it. We don't know. Maybe something bad, maybe something good. I guess we'll never know, 'cause you're going to guard it. You won't touch it, will you?
gregzoll is online now   Reply With Quote
Old 11-18-2011, 09:53 AM   #13
Banned Electrician
 
HARRY304E's Avatar
 
Join Date: Nov 2011
Location: MA, Master Electrician
Posts: 209
Rewards Points: 162
Default

Re-running 120 to my garage - want to do it right


Quote:
Originally Posted by spdorsey View Post
J.V. - Thanks for the code snippet - that answers a few questions. I have a clearer idea of what to do. When we bought the house, it had 3 structures in the backyard (the yard is 85' deep), and 2 of them had electric running to them. We tore down all except the garage, but none have elec right now. Perhaps we are grandfathered in because 2 structures had elec before? (just a shot in the dark).

Jimmy and Greg - I'd LOVE to run a 50 amp circuit to the garage, but I'm pushing the service as it is (I have 100 amp service). I just ran wire and new outlets/switches throughout the entire house and rewired much of the breaker box from knob/tube to romex. There is one spot left in the panel, and I can afford a 20/20 double breaker for the garage without overloading the house - just barely.

I may be upgrading my service sometime soon. Ugh!

The garage will be a "man cave" of sorts - containing a computer, TV, fridge, and a small photo studio. I will also use power tools in there, but not very often at all.

The replies are fantastic and very helpful. I appreciate all of them.
Run 2 ,1-1'4" PVC to the garage run 4 #10 conductors use a twp pole 30 amp breaker in your house panel to feed your sub panel.

Use another two pole breaker in the sub panel that will be your disconnect in the garage.

Drive two 5/8th's ground rods and run #6 copper to the ground rods from your sub panel.

The load you just described will never trip that breaker unless you are using Electric heat in there.

the large pipes will allow you to upgrade later on
HARRY304E is offline   Reply With Quote
The Following User Says Thank You to HARRY304E For This Useful Post:
spdorsey (11-18-2011)
Old 11-18-2011, 09:59 AM   #14
Member
 
Join Date: Mar 2011
Location: San Jose, CA
Posts: 35
Rewards Points: 25
Default

Re-running 120 to my garage - want to do it right


I'll hopefully never need heat in there, as we plan to insulate the garage before we finish the walls. I could always have a gas line run out back, it wouldn't cost much considering the savings and convenience.
spdorsey is offline   Reply With Quote
Old 11-18-2011, 10:08 AM   #15
liscenced electrician
 
Join Date: Jul 2008
Location: Oregon coast
Posts: 983
Rewards Points: 500
Default

Re-running 120 to my garage - want to do it right


I would still take 60 amps to the garage. Just because you have the available power out there doesn't mean you are overloading the service. It makes it nice that the lights won't dim everytime your refrigerator kick on. Which they likely would if you only ran #12

jimmy21 is online now   Reply With Quote
Reply

Tags
conduit, exterior, garage, trench, undergorund


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
In theory: expand attached garage, or add detached garage? hyunelan2 Building & Construction 5 11-09-2012 05:34 PM
The 12-Gauge Garage Jack Olsen Project Showcase 28 07-08-2012 10:21 PM
How to wire a detached Garage? (w/ Conduit?) FLintonRice Electrical 7 06-27-2011 01:08 PM
Water running from Driveway into Garage. CAD Building & Construction 5 06-17-2010 07:30 PM
running wire to detached garage amakarevic Electrical 2 02-28-2008 02:17 PM




Top of Page | View New Posts

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