Electrical Panel Mounting - Polebarn

bigballer · Jul 16, 2014

Wanted for get some ideas on mounting a panel in my pole barn. There are not standard 2x4 wall just post frames with horizontal purlins ad sheet metal. Was thinking about just using a large section of 3/4" plywood And attach it to the purlins. Also, can a I just run romex from the branch ckts breaker to the outlets/switches or does it need to be in conduit?

Rustyiron · Jul 16, 2014

Yes, or you could pair up (side to side) a couple of 2X10's vertically between two wall girts (purlins) at "code" level. I'd locate it to one side or the other of a post so that the wiring heading out to your circuits could be fastened to it. I can't answer your romex/conduit question, it may be a code issue for either rodent concerns or open-exposed wiring. If you are going to insulate it, you can place some vertical 2X4,6 ? vertically, then create a solid surface. Similar to how they provided support for windows or doors, this will provide a space for insulation behind the panel and "flush out" to the interior surface for interior finishing.

ace10 · Jul 16, 2014

My service panel is mounted on 3/4" OSB mounted to the window framing. I added a vertical "stud" to support the center of the OSB.

If I didn't have the window framing to work with, I would just run 2X4's between the posts (narrow side out like a stud) and then use a couple more 2X's for the vertical framing.

My OSB is 5" off the wall tin.

This is a 400A service, with a 200A panel. I used 12ga AC wire. Looking to avoid any possible issues down the road.

My electrician installed the 200A Panel and 200A cutoff. It is inspected by the county. I ran the circuits after. Inspection not required.

Will_C · Jul 16, 2014

My panel is mounted on a sheer of 3/4" OSB, similar to ace10's.

Will

bigballer · Jul 16, 2014

Thanks for the replies. I like the 2x10 idea too. My electrician will be replacing my main panel at the house so I want to get the barn prepped for the sub panel. Will be nice to scrap the extension cord currently feeding the pole barn. I'll see what he says about code on the branch feeds.

bigballer · Sep 4, 2014

Furthering work on this project, my main panel was replaced and now am ready to dig a trench to extend the wiring to the barn. The run is about 80' and I want a 50amp main in the barn for some lights and a couple outlets. Is #4 wire sufficient for this? I would run 2 hots and a neutral. At the barn, I believe the neutral and ground bars need to be separated with dedicated ground rods coming off the barn panel. Is this correct?

buickanddeere · Sep 4, 2014

bigballer said:
Furthering work on this project, my main panel was replaced and now am ready to dig a trench to extend the wiring to the barn. The run is about 80' and I want a 50amp main in the barn for some lights and a couple outlets. Is #4 wire sufficient for this? I would run 2 hots and a neutral. At the barn, I believe the neutral and ground bars need to be separated with dedicated ground rods coming off the barn panel. Is this correct?

Three insulated wires and a bare or green insulated ground.
Correct at the panels remote from the first ground to neutral bond near the utility transformer. The neutral bar must float free from the ground system . Or the ground system will be energized with neutral current and have voltage potential above true earth potential. Ground rods at every panel and the entire grounding system tied together is vital.

s219 · Sep 4, 2014

Correct, neutral and ground kept separate at barn. But you do need to run a ground wire from your home main panel in addition to the two hots and neutral. And you need an additional ground rod (or rods) at the barn.

#4 Aluminum would be fine, or #6 copper.

bigballer · Sep 5, 2014

Ok thanks, got it. 4 wires from the garage, neutral and ground bars separated at barn. Dedicated ground rods at barn. Now to get the BOM together..

BeezFun · Sep 5, 2014

buickanddeere said:
Ground rods at every panel and the entire grounding system tied together is vital.

I just had my barn wired and the electricians said the code changed a few years ago, they are no longer allowed to put separate ground rods at each location. The ground wire has to be run uninterrupted back to the ground at the main service panel, and only the main service panel can be connected to a ground rod. I called the county to confirm that, they said the same thing. Not sure if this is something local around here, or part of the NEC.