Sub Panel Attached Garage

[Toneloc]

Having a little analysis paralysis on updates to my attached garage.

I'm getting ready to wire and insulate/drywall. Trying to future proof as much as possible.

Thinking of putting a subpanel in the garage rather than running the wires from the basement.

Since I have the studs exposed, I can run romex behind the drywall for my outlets. This points to recessing the subpanel so it will be flush with the finished drywall.

But in the future, if I wanted to add a circuit, say for an Electric Car Charger, or welder, it would be better to surface mount the sub panel.

Anyone got some recommendation or pictures of how to run a panel that has both connections running behind the wall and conduit connections?

Also, is Aluminum SER my best option from the basement through the stud walls without conduit?

 

[Kevin Essiambre]

I've done panels that are recessed into the wall several times. On some we ran conduit into the attic to a junction box. On some we just left it as is and fish wires into the panel afterwards.

Surface mount is better for adding (simply because it's easier) and better for R-value if you're mounting it on an exterior wall, but how much are you anticipating to add?

Why not run a conduit now for anything you may want, then later it's just a matter of pulling in the wiring?

 

[Terry D]

Having a little analysis paralysis on updates to my attached garage.

I'm getting ready to wire and insulate/drywall. Trying to future proof as much as possible.

Thinking of putting a subpanel in the garage rather than running the wires from the basement.

Since I have the studs exposed, I can run romex behind the drywall for my outlets. This points to recessing the subpanel so it will be flush with the finished drywall.

But in the future, if I wanted to add a circuit, say for an Electric Car Charger, or welder, it would be better to surface mount the sub panel.

Anyone got some recommendation or pictures of how to run a panel that has both connections running behind the wall and conduit connections?

Also, is Aluminum SER my best option from the basement through the stud walls without conduit?

Aluminum SER is cheaper than copper. No need for conduit.

If you are going to flush mount the panel, try to run everything now before you drywall, or you will have to fish wiring later, don't know if will have a attic or not. Surface mount raceways, like EMT, seem to work better with surface mount panels. It is possible to come out of a existing flush mount panel and add EMT

 

[Toneloc]

Thanks guys. Found I can't post a picture without 5 posts. This is a basic 28x28 - 2 stall garage. I'm thinking to locate the panel in between the garage doors. Does this seem like a good location for the panel?

Reason why....

1) I was thinking right below the panel in that location would be a good spot for EV Charger in future. Also seemed like a good location for a welder outlet. Those would be easy manage so close to the panel.

2) This is thinking way far ahead, but if I ever add another 3rd stall on the garage it wouldn't be too terrible to run more wiring from this panel location.

I am planning a 220 circuit for 3.5 hp air compressor, and another for a 1.5 hp belt sander for current needs. Then just some outlets on the walls. The light circuit is already run off the main box in the basement. I have a finished office above. Previous owner put up dry wall on the ceiling already, so no easy access above.

 

[Toneloc]

Also...I'm seeing confusing info, but what size aluminum or copper would I need for a run of less than 50'?

Would prefer to run inside the wall studs, which are 2x4.

 

[Terry D]

Thanks guys. Found I can't post a picture without 5 posts. This is a basic 28x28 - 2 stall garage. I'm thinking to locate the panel in between the garage doors. Does this seem like a good location for the panel?

Reason why....

1) I was thinking right below the panel in that location would be a good spot for EV Charger in future. Also seemed like a good location for a welder outlet. Those would be easy manage so close to the panel.

2) This is thinking way far ahead, but if I ever add another 3rd stall on the garage it wouldn't be too terrible to run more wiring from this panel location.

I am planning a 220 circuit for 3.5 hp air compressor, and another for a 1.5 hp belt sander for current needs. Then just some outlets on the walls. The light circuit is already run off the main box in the basement. I have a finished office above. Previous owner put up dry wall on the ceiling already, so no easy access above.

Put the panel where it is convenient for you, there are no rules to what wall it has to be on.

 

[Terry D]

Also...I'm seeing confusing info, but what size aluminum or copper would I need for a run of less than 50'?

Would prefer to run inside the wall studs, which are 2x4.

What size sub panel are you thinking. A 6/3 copper NM-b will give you 60 amps. Depending on what is allowed in your area, a #2 Aluminum SER will give you 90 or 100 amps. You do not have to worry about any voltage drop with that short distance

 

[Toneloc]

I'd like to go 100 AMP.

I see # 3 copper is good for 100AMP @ 75C.

I was thinking 3-3-3-5 copper SER, which is 0.9" in diameter, so thinking this will be fishable through the 2x4 studding with too big of a hole.

 

[Terry D]

I'd like to go 100 AMP.

I see # 3 copper is good for 100AMP @ 75C.

I was thinking 3-3-3-5 copper SER, which is 0.9" in diameter, so thinking this will be fishable through the 2x4 studding with too big of a hole.

#2 aluminum is much cheaper, not that much larger

 

[pattenp]

Be aware that SER cable if run within insulation needs to be sized based on 60degC, not 75degC. NEC 338.10(B)(4). There is leeway under 310.15(A)(2) Exception. If less than 10% of the SER is within insulation to a max of 10ft then you can use 75degC.

 

[Terry D]

Be aware that SER cable if run within insulation needs to be sized based on 60degC, not 75degC. NEC 338.10(B)(4). There is leeway under 310.15(A)(2) Exception. If less than 10% of the SER is within insulation to a max of 10ft then you can use 75degC.

Am I reading this wrong, its says for cables with the ungrounded conductor # 10 or smaller

 

[mobetta]

I would not put my panel between two overheads.
nor my welder

car chargers generally have a 25' cord on em

 

[alfredeneuman]

I have a finished office above. Previous owner put up dry wall on the ceiling already, so no easy access above.

Drywall (or plaster) is required any where the garage shares common wall or ceiling with a "living space".
I'd run flex conduit through the walls to future proof. That way you can add wires for any changes.

 

[pattenp]

Am I reading this wrong, its says for cables with the ungrounded conductor # 10 or smaller

Where are you reading this from? I see no wording of the such in 310.15(A)(2) or 338.10(B)(4)

 

[Terry D]

Where are you reading this from? I see no wording of the such in 310.15(A)(2) or 338.10(B)(4)

338.10(B)(4) of the 2017 NEC. Page 195 top left. It is shaded. so possibly a change from 2014

 

[pattenp]

338.10(B)(4) of the 2017 NEC. Page 195 top left. It is shaded. so possibly a change from 2014

Don't have my 2017 book with me. I was looking at the 2014. Need to update myself. Thanks.

 

[Terry D]

Don't have my 2017 book with me. I was looking at the 2014. Need to update myself. Thanks.

I looked it up because I was never aware of it. The only other book I have is a 2008, there is nothing about installing it where it will be covered by insulation

 

[pattenp]

I looked it up because I was never aware of it. The only other book I have is a 2008, there is nothing about installing it where it will be covered by insulation

The insulation part was added in 2011. Actually I need to get a 2020 book as I don't like using the online version on the NFPA site.
It just dawned on me why the #10 or smaller change when I believe #8 is the smallest SE comes in.

 

[larry4406]

Drywall repairs are quite easy should you decide to fish some circuits later. Flush mounting of panels and outlets is not the fatal end-all inflexible decision that some make it out to be. Yes its an extra step but certainly not the end of the world.

 

[ROBZ71LM7]

I did a surface mount panel because my garage was already built and I would've had to remove almost all the drywall all the way around my garage to add circuits (it's a big one). Having done it both ways here's my opinion:

Conduit
Pros
Great for making modifications and ease of upgrading or adding circuits
Looks industrial (maybe a plus)

Cons
Higher cost
Extra area to catch dirt
Appearance maybe a con for some
Takes up wall space

Romex in walls
Pros
Cheaper!
Cleaner appearance
Cons
Difficult to add after the fact or upgrade service
Difficult to add circuits


If I built from scratch I would do a hybrid. I would flush mount the panel and run romex for 3 different 120V circuits all around the shop with lots of outlets everywhere. There is little risk of having to modify that circuits. I'd also run a couple 240 circuits in the wall if I know where I might weld or have an air compressor, mini-split, etc.

Next I would surface mount two or three of decent sized 4-11/16" junction boxes and run conduit from the flush box to each of these. Keep the conduit between the boxes and panel to 24" or less and you can do 60% fill without derating. This leaves you with tons of options for future surface conduit runs without having to ever touch drywall again or fish circuits into the attic and down the wall.

 

[alfredeneuman]

Cons
Takes up wall space

The wall space for a panel is required to have a 30"W X 36"D workspace (without any obstructions) anyway

 

[ROBZ71LM7]

The wall space for a panel is required to have a 30"W X 36"D workspace (without any obstructions) anyway

My bad for not being clear, I was referring to the wall space potentially lost or hindered from all the surface mount conduit. In my situation the conduit has limited my usage of the wall space in areas.

 

[quickfarms]

I my garage the welder outlet and two 110 circuits are located in the wall between the garage doors and is very convenient when working in the driveway which is normal in Southern California

When I built my current shop 18 years ago I installed a 100 amp sub panel and over wired the shop with two 220 volt outlets, compressors are in the old garage and feed the shop using an underground pipe, and 12 110 circuits. All the wire was run in rigid pvc under the slab and flexible conduit in the walls with additional conduits for future expansion.

The conduit has made any additions and alterations very simple.

Additionally I ran two empty 3/4 conduits from the main panel to the sub panel for future yard lighting. These conduits are going to be used for a RV pedestal and two 50 amp circuits to the new shop which is going to be located between the panels.