NM cable in red iron building?

[vlocci]

I'm pretty close to buying a red iron garage unit and am starting to collect parts for wiring/lighting etc.

The unit has 28-32 foot ceilings, so I'm planning on installing several high bay lights (either Metal Halide or High pressure Sodium)

My NEC has gone MIA in the move, but I recall somewhere that NM cable (or was it flexible cable?) could be used above a height where people could not come into contact with it.

This said, is it permissible to run NM to junction boxes for each light, then transition to conduit when I get closer to ground level? Am I making up the part about NM being permissible in exposed conditions above a certain height?

I'm looking to prevent numerous conduit runs (and multiple bends) to each fixture. Something flexible like NM cable would make the install much easier.

As an aside, anyone have a lead on cheap/used high bay lighting? I'm in the Northeast, and could pick up as required.

Thanks in advance,

Vin

 

[mrb]

Even if i were allowed to use NM for that, I wouldnt. Its going to look like ****. If you dont want to spend the time doing it in pipe, use MC cable. Its not that much more than romex iirc. Caddy makes clips that will attach it to the steel.

When youre shopping for highbay lights pay attention to the voltage, alot of the super cheap used ones out there have 277v ballasts.

 

[Charles (in GA)]

334.10 Uses Permitted Types NM, NMC, and NMS. Types NM, Type NMC and Type NMS cables shall be permitted to be used in the following:

(1) One and two family dwellings.
(2) Multi-family dwellings permitted to be of Types III, IV, and V construction except as prohibited in 334.12
(3) Other structured permitted to be of Types III, IV, and V construction except as prohibited in 334.12. Cables shall be concealed within walls, floors, or ceilings that provide a thermal barrier of material that has at least a 15-minute flash rating as identified in listings of fire rated assemblies. (NFPA 220-2006 defines construction and occupancy classifications..... and I don't have that, sorry!)

334.12 Uses Not Permitted.
(A) Types NM, NMC, and NMS. Types NM, NMC and NMS cables shall not be permitted as follows:
(1) In any dwelling or structure not specifically permitted in 334.10(1), (2), and (3).

I didn't type the whole section by any means, just the paragraphs that seem relevant here. Its lengthy and you need to read the whole thing to understand it, but I suspect from reading it, that the simple answer would be NO, you cannot have exposed NM in this building. I used conduit in my steel building. Edit: forgot to add, if you were to use exposed NM you are leaving it open to rodents to chew away at. Yes, they can climb and NM would provide an excellent way for them to travel.

Whatever you do, if you intend to do any work in this building, DO NOT use SODIUM lighting. It has a orange hue to it and is very annoying to work under. Either use MH (pulse start is the current version and much better than the older probe start like I have) or use high bay fluorescents either T5's or T8's. Let your wallet be your guide.

If you hang the fixtures on hooks and rings, it is best, easiest to use cord and plugs to receptacles mounted next to the fixtures. Use cord rated for 105C as that is what the wires in the fixture that you are splicing to are rated at.

Charles

Link to my lighting project

Link to my ceiling fan installation.

Thread on high bay lights.

Link to a thread on securing conduit in metal building and some of my conduit work.

Best discussion I've found on how to measure for and bend conduit in a sensible, readable, format..

Charles

 

[Aceman]

Run MC cable if you don't like conduit, but don't use Romex. I'd still want to protect the MC cable below 8' though. Whether you switch over to conduit or hide it behind a post, anything to keep it from hanging the in free air.

I don't really care for highbays myself. The light doesn't disperse as well as it should in my opinion for a shop atmosphere. We're using a lot more T5HO 4-6 lamp fixtures then we used too for the high ceilings now. Instant on and off with no warm up time, not to mention you'll never hear a ballast buzzing like high bays sometimes do. They draw less electricity too.