Surface mounting a subpanel

[utbigrod]

Hey, all! Been lurking for a while reading up a bunch on different people's projects and have found lots of good info, so thanks for that! I am adding a subpanel in my attached garage and have a few questions that I haven't exactly found the answers to yet.

Quick background:
I'll be running the panel (a Homeline 12 space 24 circuit main lug panel...my other boxes are also Homeline) off my main, which is outside located on the exterior side of my garage. The run will be simple enough as I plan to locate the subpanel almost directly on the other side of it. I'll be using a 2" pvc LB to come out of the main and into the interior wall. I'm running 2/2/2/4 SER cable off a 90A on the main to the main lug. I'll have 3 20A 120V circuits and 1 or 2 30A 240V circuits (with GFCI first in line). I have a main subpanel for the house which includes some garage wiring already that handles the lights, garage door openers, exterior lights and a few plugs in the garage. I'll be running woodworking machines mainly on these circuits. Also I plan to surface mount the panel on a 3/4" backer which I will apply to the finished drywall vs. cutting out a slot for the ply like I've seen others do. I will then use EMT. Even though I'd love a clean look, my goal is complete flexibility and even easy removal if and when I move out.

Questions:

1. I want to run the 2/2/2/4 straight into the back of the subpanel so there isn't an LB on the interior that then enters the bottom of the box. Any issues doing that through 3/4" ply the subpanel will be mounted on? I know I need to anchor the cable 12" from entry
2. After I enter the interior cavity with the 2/2/2/4 can I immediately (within a few inches) leave the PVC and just snake the cable to the box (with aforementioned anchoring)?
3. I plan to use quad outlets everywhere I do 120V. I see 4" and 4-11/16" boxes at the home center. Any reason not to use the larger ones so I have plenty of room?

Thanks for any input you can give, I appreciate and respect the knowledge on this board!

Rod

 

[utbigrod]

Hmmm, I'm trying to figure out if my topic is just not interesting or if I somehow posted this wrong and so not many are seeing this.

Any insights?

Sorry for the newbness of this post.

 

[RickP]

The only issue I see for you to consider is future expansion - you'll need a main breaker in the subpanel if you want to use more than 6 breakers. You'll be fine at first because you're only using 4 - 5 circuits. I'm not really sure about the answers to your other questions.

 

[utbigrod]

The only issue I see for you to consider is future expansion - you'll need a main breaker in the subpanel if you want to use more than 6 breakers. You'll be fine at first because you're only using 4 - 5 circuits. I'm not really sure about the answers to your other questions.

Rick, it's my understanding that because in in the same attached building as the main panel that I don't need a shutoff. That the main breaker shutoff only applies after 6 circuits in detached structures. That's at least what I read in several other posts

 

[RickP]

Good call - I completely spaced on your comment that it was an attached garage. I've added a similar subpanel to my attached garage, but my subpanel is a lot smaller than yours.

 

[pattenp]

Questions:

1. I want to run the 2/2/2/4 straight into the back of the subpanel so there isn't an LB on the interior that then enters the bottom of the box. Any issues doing that through 3/4" ply the subpanel will be mounted on? I know I need to anchor the cable 12" from entry
   
   You can enter back, use a NM clamp or bushing in the knockout. If using bushing staple cable within 12" of the entry point of the cable into the panel.
   
   
2. After I enter the interior cavity with the 2/2/2/4 can I immediately (within a few inches) leave the PVC and just snake the cable to the box (with aforementioned anchoring)?
   
   Yes.
   
   
3. I plan to use quad outlets everywhere I do 120V. I see 4" and 4-11/16" boxes at the home center. Any reason not to use the larger ones so I have plenty of room?
   
   Larger is better, gives you room for installing the outlets.

Thanks for any input you can give, I appreciate and respect the knowledge on this board!

Brad

I recommend the main breaker just for convenience even though you aren't required to have it.





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[utbigrod]

I recommend the main breaker just for convenience even though you aren't required to have it.





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Thanks for the feedback! So if I understand what you are saying, if I use a 1.5" NM cable clamp on the 2/2/2/4 at the box then I don't need to secure it 12" from the subpanel entry?