Electrician types... any input on garage sub panel install?

[jeffesonm]

I'm installing a sub panel in my attached garage. 200 amp service at the main box. I am running 2/2/2/4 Al SER about 25' through a crawlspace to the wall between the house and garage, where I will mount the subpanel. Inspector confirmed this is not considered a fire wall in my single family residence. He also said the 2/2/2/4 is good for 90 amps, but I am just going to do a 60 amp breaker in the main for now and can always up it later in the rare chance I need more.

With the wall cavity open it's easy to run cable up through the wall and into the new panel. For now I'm just going to add a 240V/50A welder outlet, a 240V/30A compressor circuit and a few 125V/20A outlets.



I have access to the unfinished attic, above, and to the crawspace below/behind (garage on slab, crawlspace under adjoining house). In the future I could fish wires down from the attic or up through the crawlspace, not sure how I would attach cable clamps to the box once it's in the wall. Is there something I should be doing now to make my life easier when I want to add more circuits later? Should I run a few stubs up/down to junction boxes? Or maybe a few pieces of conduit? But I think no NM/B in conduit. Cut out more sheetrock and install an access panel? I like to keep things clean as possible...

 

[seige101]

Couple different options. You could run a conduit from the panel up the wall to the attic and put a junction box up there. You would terminate your romex in the box, strip the sheathing and pull the wires down the conduit into the sub panel.

You can attach the connector to the cable and fish it down the wall, only having to install the locknut in the breaker box it self.

Or you can use plastic push in romex connectors. You would take out the knockout in the top of the sub panel, fish the wire in and then place the connector inside. http://www.rack-a-tiers.com/product/65/Tom-2-Way-Connectors-12

 

[Oldman47]

I am building a new home and stubbed out 6 circuits, 3-20 amp and 3-15 amp, through the floor into my basement. When I got to the basement space I terminated each one in its own junction box ready for me to splice right into them. I used a marker to mark the circuit number right on the face of each box so that when/if I decide to use those circuits I will know exactly what I have and where each one is powered. The breakers are already installed but left open and the wire was run to those boxes before I closed up the wall. As an example, if I find I want a new lighting circuit I will just use a 15 amp installed spare for it. My total cost was a half dozen breakers at around $5 each, a half dozen junction boxes at around $2 each and around 25 feet of #12 and 25 feet of #14 Romex (at ridiculous prices this year). I saved all of the hassle of future wire fishing, all of it.

 

[Enzo's Dad]

Feed as many wires through the side of the panel before you mount it. Leave the top as open as possible. It is easy to snake wires through the punch outs in the top.
If you think your going to add later can cut back sheet rock an trim the panel in wood to look more finished. Don't over think it you are doing fine.

 

[ironpony]

Hate to question the inspector but, if it is a wall between the garage and living space it is a firewall and should be 5/8 drywall minimum. now there could be some kind of grandfather clause being it is existing. your electrical sounds good, what ever you plan for it will change so don't sweat it.

 

[jeffesonm]

Thanks for the feedback all. I did not realize they made clamps you can push in from the inside, that makes life a lot easier. I have some short sections of leftover wire that aren't much use for anything, so I may as well run a few stubs to junction boxes in the attic and basement. Can I just run them into the panel and leave the excess wire rolled up neatly in the corner?

As for the firewall, ultimately for me it comes down to my inspector. But for the sake of code discussion, which I find interesting as I like semantics... the general concensus online seemed to be the wall between the garage and living space is a firewall, but adding a second layer of sheet rock behind the panel would bring you back into compliance. I did come across this one discussion that aligned with my inspector's position.

 

[Oldman47]

Yes, you could leave the wire just coiled inside the panel if you want to. I went ahead and installed the breakers for mine so that the dead front never needs to come off if I want to tie into a circuit. I would just run from the box to the final destination and turn on the associated breaker.

 

[therdlesstravld]

You can put Romex inside of conduit you just cannot attach it to a box/panel on both ends. It's classified as a protective raceway in that case. I'd bring all my wires in from the sides and bottom and then attach plenty of short runs of conduit into the top and terminate them through the top plate and into the attic. That way you could easily drop the new runs down into the panel.

I just dealt with this for the electric hot water heater in a house I'm flipping. I ran 3/4" schedule 40 from the heater up into the ceiling and put a street elbow on it and then stapled the wire like normal. Use a connector on the ends of each stub as cut PVC can be a little sharp (plus they'll want it there by code).

 

[semipro]

Most require a floating ground.
Technically, even cables clamped at the box need to be secured externally of the box and within a certain distance. https://www.hearth.com/talk/threads...box-in-new-circuit-panel.137937/#post-1861306
IIRC there was a good discussion on related to panel installation in the DIY room. https://www.hearth.com/talk/threads/100-200-amp-service-upgrade-box-in-new-circuit-panel.137937/

 

[seige101]

Most require a floating ground.
Technically, even cables clamped at the box need to be secured externally of the box and within a certain distance. https://www.hearth.com/talk/threads...box-in-new-circuit-panel.137937/#post-1861306
IIRC there was a good discussion on related to panel installation in the DIY room. https://www.hearth.com/talk/threads/100-200-amp-service-upgrade-box-in-new-circuit-panel.137937/

Exception if you fish the wires into a finished wall

 

[billb3]

It's sheetrock ?

In the future you cut a piece(s) out, expose enough to run a new wire properly and patch it back up.

 

[Oldman47]

Too much work Billb3. If you plan ahead you can have the circuits stubbed out and avoid that drywall mess.

 

[billb3]

So is carrying in a 50 pound bag of pellets.

I guess if drywall is a "mess" then it is too much work. It shouldn't be a "mess".

 

[Oldman47]

Sorry, but to me cutting and then patching drywall, especially around a breaker box is something I would really prefer to avoid and I can do so simply by stubbing out a few future circuits to an accessible junction box.

 

[pen]

going to slide this over to the DIY room, but leave a link here.

pen