Simple Electrical Question

[Thomas Marr]

I bought some nice fluorescent lights at the Habitat Restore. When I install them, there will be a short distance between each light (i.e., maybe a foot or two). For the electrical wire connecting the lights...does it have to be in conduit? How far can I "sting a wire" that's surface mounted and not in conduit? BTW, this is in a barn.

[Jim O'Dell]

I don't think I'd want exposed wiring in my building like that, but it probably wouldn't be a problem if you don't have to meet code. If it has to be inspected, bite the bullet and use some metal flex between fixtures with a connector mounted in each fixture, then snake the wire through. It shouldn't be that bad to do. Jim.

[Frank Hagan]

Barns usually fall under "agricultural" buildings, but you have to check locally to see if the local agency having jurisdiction agrees. I found a reference to Article 547 of the NEC (but its from a 2004 post using the 2002 NEC; I think they update it every four years, but it all depends on which code your local jurisdiction has adopted.) Its at this forum post (http://www.chronicleforums.com/Forum/archive/index.php/t-25764.html):



Article 547, "Agricultural Buildings" ... Under Article 547, the only approved wiring methods are:
1) Type UF cable (direct burial underground cable), sleeved for mechanical protection in PVC conduit where subject to physical damage.
2) Type NMC cable (a corrosion-resistant variant of above), sleeved for mechanical protection in PVC where exposed to physical damage.
3) Copper SE cable (plastic-jacketed service entrance cable)
4) Jacketed type MC cable (similar to armored cable but with a thermoplastic over-coating and
a seperate ground wire)
5) Rigid nonmetallic conduit (PVC)
6) Liquidtight flexible nonmetallic conduit ("sealtight") A flexible variant of PVC conduit.


If your barn is really a storage shed, and does not suffer from the extra condensation that storage of hay, animals, etc., bring then the code is more lenient, according to the electrician in that forum post.

[Rod Sheridan]

If not subject to mechanical injury, use non metallic cable rated for barns, or use PVC conduit.

I would use PVC, it will look much neater than NM wire, that's what I used in my inlaws barn.

Make sure that any boxes or fixtures are rated for use in a barn, no standard dry use types permitted.

Regards, Rod.

[Thomas Marr]

Thanks guys. Very helpful.