100amp Subpanel Surface Mounting Question (straight through drywall?)

[RickDel]

Hello, I'm planning to install my 100amp subpanel in my garage tomorrow but have a couple questions and I wasn't able to reach my inspector today for help.

I'm installing a subpanel on the garage wall separating the house from the garage.

Can I bring the SER directly into the back of the subpanel through the drywall or do I need to mount the subpanel on a sheet of plywood? I saw a few comments on this related to fire protection but not sure it applies to my situation.

I was planning to cut a hole big enough to accommodate the cable connector, then connect the SER with a connector to the subpanel off the wall, and then mount the subpanel to the drywall. Can I do this or do I need some type backing behind the subpanel or do I need to do something to the hole behind the subpanel for fire protection?


Thanks! - Rick

 

[AntonLargiader]

So you are surface mounting the panel? The branch circuit cables need to be secured to something after they exit; that's part of why people mount on plywood. How are they running when they leave the panel?

2x4 studs in that wall? That's a tight bend on the SER. Doable, but tight.

 

[RickDel]

Thanks for the response.

I just mounted it directly to the wall.

[/URL][/IMG]

Here's from the basement up through the wall cavity.

[/URL][/IMG]


I'm ready to run the conduit, but need to find an EMT Tee fitting first. They only sell Rigid Tee's at HD and Lowes and my local supply store is closed on the weekends.

 

[ard]

EMT Tee?

If you are coming out of that box, then Teeing for a left and right run, consider just two 90s sweeping each way.

Looks good!

 

[RickDel]

ard, thanks....

I'm thinking of running a 50amp receptacle left and right, but also want to run a 20amp through the same conduit on one run, thus the T fitting like this:

They sell this exact one at Lowes and HD, but it's threaded for Rigid. If I'm not mistaken, that won't work with regular EMT.

 

[walrus]

ard, thanks....

I'm thinking of running a 50amp receptacle left and right, but also want to run a 20amp through the same conduit on one run, thus the T fitting like this:

They sell this exact one at Lowes and HD, but it's threaded for Rigid. If I'm not mistaken, that won't work with regular EMT.

It will if you put emt connectors in the threaded ends of the lb

Sent from my SM-G950U using Tapatalk

 

[RickDel]

It will if you put emt connectors in the threaded ends of the lb

I noticed the EMT connector fit, but wasn't sure if that was allowed.

So, is there any advantage of using an EMT fitting with the set screw already attached versus just a Rigid LB and using an EMT connector?

If not, I may just do that.

Thanks

 

[walrus]

No advantage, more expensive probably.

Sent from my SM-G950U using Tapatalk

 

[brewchief]

4X4 box and blank cover will do the same thing as a tee will do here.

Watch your conduit fill if running 2 50 and one 20 amp circuit down through one pipe.

 

[RickDel]

brewchief, thanks....

I'm only running one 50amp and one 20amp in 3/4 EMT. The other 50amp will be in it's own 3/4 EMT conduit.

I still need to figure out if the LB I use will be NEC approved to spice the 50/20 ground. I know I can use one conductor for both as long as I use the larger AWG. I'm just not sure if I want to spice it or run two separate grounds.

Maybe I'll need to use the 4x4 box.