Adding electrical outlets to my garage


  #1  
Old 03-06-22, 10:47 AM
M
Member
Thread Starter
Join Date: Mar 2022
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Adding electrical outlets to my garage

Electrical project (hope this makes sense!)

My garage needs additional power outlets so I will be running (qty 2) romex 12/2 cables from the electrical panel on one side of my basement, through the floor joists (along with all the other wiring in my house) to the other side of the basement. There I will be installing a junction box and switching to thin wires. These wires will go through conduit from the junction box, through the end joist of the house and into my garage (close to the floor.)

I would run these thin wires on the outside of the finished drywall in a conduit to the garage ceiling, where it then will make about a 4í run to the right. Here I reach an exposed unfinished wall (that I will be insulating and finishing later). I would use conduit through the wall studs to run the thin wires to the new outlet drop locations.

Next year I will be adding a sunroom to the back of the house. Since my 200 amp electrical panel will now be full with no more available spots, I will be removing the 2 breakers I am using to add power to the garage. Now I can use these 2 open spots to add a 100 amp subpanel next to the main panel. Then I can re-route the 2 garage wires into breakers in this subpanel. From this subpanel I will later run circuits to the sunroom and a single circuit through the back yard into a shed.

Does this all sound correct? What am I doing wrong (other than getting the subpanel now which I canít). Is there a better way to do this? Am I correct that I cannot run romex through the small conduit AND I canít just run bare thin wiring in the insulated (exposed) wall without using conduit through the studs?

What kind of wiring/conduit should I be using for this project? Everything needs to be 100% to code because I will be getting the subpanel project permitted and I will be selling the house in a few years and donít want any issues.

Thanks again! I have some limited experience with electrical and a neighbor who says he knows how to do all this Ė but I just donít want to trust that he knows ďthe properĒ way to do all this lol.

A million thanks for your input!

Mike

 
  #2  
Old 03-06-22, 11:01 AM
S
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 20,211
Received 1,177 Likes on 1,135 Posts
I didn't see anything about whether the garage was attached to the house. Also, to be technical, I believe you should be talking about THHN/THWN wire when you use the word "thin."
 
  #3  
Old 03-06-22, 11:26 AM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 15,026
Received 625 Likes on 534 Posts
Rather then running 2 - 12/2 cables you may run a 12/3 cable a share the neutral between the two hots. You will have to handle tie the two single pole breaker to meet code.

I would recomend running the cable(s) all the way into the garage and install the juction box down low since you will likely need a juction box there anyway to make the hard 90 degree turn. The cable(s) will come into the back of the juction box and there you can convert to THHN wires in conduit.

It may be dificult to run conduit inside the walls so it might be easier to run 2 -12/2 cables where the drywall ends. You can run Romex inside conduit as long as the conduit is large enough. A 3/4" conduit I belive is large enough for 2 - 12/2 cables. Just makes sure to bush the end of the conduit with a connector or coupling where the cables leave the conduit.
 
  #4  
Old 03-06-22, 12:50 PM
M
Member
Thread Starter
Join Date: Mar 2022
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Thanks! Yes, sorry the garage is attached to the house and the THHN wires are what I think I mean. I've only ever worked with romex so I didn't know THHN wires were a thing. Learning about them now.

I will look into the 12/3 wire and handle tie idea. I should have said that one circuit is dedicated for two radiant heaters I have mounted in my garage/future wood shop and suspended from the ceiling. So the outlet for these will be installed on the ceiling. The other circuit will be for outlets in the "yet to be drywalled" wall of my garage to handle running a few power tools. If I run the 12/3 wire then both circuits will trip if one does, correct?

Another, maybe more simple option for me, is to just run romex everywhere. The wall that is currently finished is only about a 3 ft section, then it meets up with the unfinished areas. I'm hanging 10 sheets of drywall, might be easier on me to just replace that piece too. Actually, I can probably run the wire in the wall without doing much damage to the drywall. It's only about 3' so I'm pretty sure I can just bore a hole right through a few studs with an extended drill bit. Then the only place I think I really need conduit will be across the ceiling for the heater outlet.

One last question - I have two courses of concrete block running around the garage, with the sill and wall sitting on top. Am I okay to run romex just above the sill (ie, not very far up the drywall) since the two blocks puts me 16" off the finished garage floor?
 
  #5  
Old 03-06-22, 01:59 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 70,890
Received 3,154 Likes on 2,834 Posts
A 12/3 NM-b cable will give you 2) 120v @ 20A circuits.
Will that be enough for your hanging heaters ?
Most garage heaters are 240v.
 
  #6  
Old 03-06-22, 02:58 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 15,026
Received 625 Likes on 534 Posts
If I run the 12/3 wire then both circuits will trip if one does, correct?
No. Only one will trip as they are handle ties together and not a common trip two pole breaker. (Note: you can use a two pole if you choose)

I have two courses of concrete block running around the garage, with the sill and wall sitting on top. Am I okay to run romex just above the sill (ie, not very far up the drywall) since the two blocks puts me 16" off the finished garage floor?
Yes.

Since you are talking about a wood shop perhaps you should look into install a smaller sub panel in the garage for the wood shop. Something like 40-60 amp circuit and an 8 to 12 space MLO panel would be all that you need and should carry just about everything you will want to run. Just some food for thought.

 
  #7  
Old 03-06-22, 03:02 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 70,890
Received 3,154 Likes on 2,834 Posts
If I run the 12/3 wire then both circuits will trip if one does, correct?
If there is a tie handle in place then both MAY trip together.
 
  #8  
Old 03-06-22, 03:56 PM
M
Member
Thread Starter
Join Date: Mar 2022
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
A 12/3 NM-b cable will give you 2) 120v @ 20A circuits.
Will that be enough for your hanging heaters ?
Most garage heaters are 240v
These are just small radiant heaters I bought on Amazon. They work pretty well, just to take the chill out of my table area. Don't tell anyone but they are currently running together on a 20amp circuit via a 100' cheap old extension cord running out to my backyard where I had a small spa years ago and still have a circuit there. I just did it as a test but since they are working I left it while it was cold. I need a better setup for next winter so time to lose the extension cord.

​​​​​​​Since you are talking about a wood shop perhaps you should look into install a smaller sub panel in the garage for the wood shop. Something like 40-60 amp circuit and an 8 to 12 space MLO panel would be all that you need and should carry just about everything you will want to run. Just some food for thought.
Actually this was the original plan, however now that we are committed to a shed and sunroom on the side of the house opposite the garage (right near the main electrical panel) it seemed better to put the subpanel there. It's not much of a wood shop, just a few power tools. I want to run my table saw and have my compressor kick on at the same time without tripping the circuit. That got old quick!

 
  #9  
Old 03-06-22, 04:15 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 11,165
Received 166 Likes on 149 Posts
So the outlet for these will be installed on the ceiling. The other circuit will be for outlets in the "yet to be drywalled" wall of my garage to handle running a few power tools.
You need GFCI protection for each receptacle, however, the GFCI receptacle cannot be on the ceiling as it wouldn't be readily accessible. For the ceiling mounted receptacle I'd install a dead front GFCI device on the wall and use a normal duplex receptacle on the ceiling.
 
  #10  
Old 03-06-22, 04:28 PM
P
Member
Join Date: Feb 2016
Location: United States, Virginia
Posts: 1,856
Received 214 Likes on 181 Posts
In my experience 2 single pole breakes with a handle tie provides independent trip. That's the reason for using 2 singles vs. a 2 pole common trip.
 
The following users liked this post:
  #11  
Old 03-06-22, 06:06 PM
M
Member
Thread Starter
Join Date: Mar 2022
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
You need GFCI protection for each receptacle, however, the GFCI receptacle cannot be on the ceiling as it wouldn't be readily accessible. For the ceiling mounted receptacle I'd install a dead front GFCI device on the wall and use a normal duplex receptacle on the ceiling.
Thanks! I'll do that. In the summer when I am not running my heaters that circuit would be unused. This way I can use it if I want, and in winter I just won't use it.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: