Metal Barn Wiring Questions

Old 11-21-15, 01:55 PM
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Metal Barn Wiring Questions

I have a 40x25 metal framed barn on concrete. The previous owner ran a 125A/24 space panel to the barn; however, he used an indoor panel, left the cover off, and the barn leaks in that area. There are only a couple of breakers coming off it, but I don't trust the panel to add/make changes.

Since I am converting the barn to a woodworking/welding shop, I need to get the electrical straightened out. So here is the plan...

I will run wiring throughout the barn for lights, standard outlets, and a few 208-240 circuits. Afterward, I plan to have an electrician come out and pull/replace the panel and wire everything in.

1. The trusses and posts are all two inch pipe, so I will likely run need to run everything along the outside.
a. What kind of conduit/wire would you recommend?
b. How would you secure it to the the pipe?
2. How much of a service loop should be left at the panel end for an electrician so that he can install into a new panel (panel cannot be moved much, as the feed comes up from PVC set into the concrete pad)?
3. While I will likely run 15 Amp receptacles to ground level, do you see any issues with using drop style outlets for all higher output circuits?

Please note, I am in not in a city limits (unincorporated county) and there are no "inspections" needed. I do; however, want to use best practices and make sure everything is safe.
Old 11-21-15, 03:36 PM
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Based on how the barn is constructed I would recommend using a metal raceway such as EMT. This will allow you to install whatever wires you need. It will also allow you to add wires later for your evolving shop. That said I would recommend fixing the leak and changing the panel first.

To attach the raceways to the metal pipe I would use a conduit hanger and attach them to the pipe with self tapping screws.

Last edited by pcboss; 11-21-15 at 04:35 PM. Reason: tapping
Old 11-21-15, 03:50 PM
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I agree, fixing the leaks is far more important to anything below it, then the wiring.
Do you know where the cover is for the panel?
If not it may be easier to replace the whole panel then to try and find just a cover for it.
Your also going to need permits for this work.
Old 11-21-15, 04:37 PM
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There are different styles of clamps and mounting methods to secure conduit to the building. Caddy would be a good place to start. You will have better luck at an electrical supply house than a hardware store
Old 11-21-15, 06:06 PM
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he used an indoor panel, left the cover off, and the barn leaks in that area
The indoor, NEMA 1, panel was the proper choice unless the panel was installed outside. The roof leak is not proper, fix it.
Old 11-21-15, 07:38 PM
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These are the type of conduit clamps/hangers that I would use. They come in all sizes.
Old 11-23-15, 12:16 PM
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Thank's to all for the replys and suggestions. This will be great to get me started. Couple of notes/questions...

Panel/Cover: While I have found, and installed, the panel cover, I plan to just replace the unit. When I bought the place, the panel was full of debris, a wasp nest, and there is a lot corrosion. I replaced the cover, but figure "replace" is the overall better/safer long term bet.

Leaks: Fixing the leaks may be an issue. First, my primary concern here is going to be thousands of dollars worth of equipment I am installing. So far, I have patched the roof leaks (mostly missing screws) and I am currently replacing couple sections of wall which were cut out for animal access, including a missing 12'x8' section. Problem with leaks and the panel are twofold...
1. The panel is right next to 12' high double sliding barn door (I know better than to believe it will always be shut during bad weather).
2. The barn was largely home built by the previous owner using 2" (horizontals) and 3" (verticals) drill stem pipe. This has led to a rock solid building, but one with lots of gaps, spaces, and such. Doubt I will ever completely seal it.

Questions: Is there is any good reason I couldn't just treat the whole thing as an outdoor project (think...barn w/o walls...much like I lot of livestock auction houses) and install the panel, cables, conduit, and connections all outdoor rated? This might be the way to go, as down the road in a couple years, I might convert the barn into a canine rescue/rehab kennel. This this would be one less concern before being able to hose out the interior on a daily basis. If I do go that way, GFI everything? Other suggestions along this lines?
Old 11-23-15, 01:51 PM
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Yes you can do that. The main issue is cost and some wire routing issues (can't run out the top of the panel). You would need to use all NEMA 3R or 3X boxes (outdoor rated), die cast metal or plastic outlet boxes (bell boxes), all 120V receptacles need to be GFCI in barn anyway so that is the same. You would need to install in-use plastic bubble covers on all outlets, and all wiring methods would need to be wet rated. Either UF-B cable with proper watertight cable fittings or conduit (rigid PVC, EMT, or liquidtight) with individual THWN wiring pulled in. If you do intend to keep dogs in there, I would recommend EMT conduit in areas they can reach. Large breeds can easily chew through plastic conduit (my labrador loves PVC offcuts and they're much cheaper than nylabones).

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