I'm wiring one family dwelling with a seperate barn used for horses only.
Is the horse barn considered an agricultural building and subject to NEC article 547
Article 547 allows type NMC to be used in an agricultural building...but I question its use because I think it would be subject to damage by mice and other rodents creating fire hazards...what do you think?
Buildings on the same lot as a single family dwelling are considered as accessory to the dwelling and the same building code rules apply to those buildings. But, all wiring must be done using wiring methods appropriate for the conditions of use. Also, if the wiring in any location is subject to abuse of any kind, then you must choose a wiring method that can withstand such abuse or provide protection for the wiring method used. A horse barn on a residential lot is subject to the rules of Article 547, but COULD be wired with NM in clean, dry, protected areas. There are no habitable areas in a horse barn, and power is not even required to accessory buildings. Looking at the scope of Article 547, I see that only those agricultural buildings or portions of those agricultural buildings that have excessive dust, water or corrosive conditions need comply with the requirements of 547. (Note also 547.3) So, all things considered, NMC is OK. If you are concerned about possible rodent abuse to the wiring, then protect it: run rigid, intermediate, EMT or PVC conduit
Re: Horse Barn#90543 11/25/0411:08 AM11/25/0411:08 AM
Interesting question George. I don't see NM-C in the current Greybar catalog. I just assumed it was something you buy at the feed store. About 99% of the "farm" stuff is unpermitted and uninspected if my Florida experience means much. I know a lot of people with "ag" property (in a semi suburban area) and they never get permits to do work on the property. The general feeling is ag is exempt from everything. Some ugly work it is too.
Agricultural is exempt from inspection in the State of Michigan, which is sad because there are a lot of farmers who would like the satisfaction of knowing that their wiring is safe. As an inspector, I have no authority and no code reference when it comes to inspections on anything except the dwelling on a farm. That's one subject. But my question is: If I was to use NMC where would I purchase it? When we had a speaker at our IAEI seminar, he said that they don't manufacture NMC due to the lack of market demand. Is that true?
Re: Horse Barn#90546 11/26/0401:26 AM11/26/0401:26 AM
When I looked at the Paige cable web site NMC-b seems to be the same as UF or at least that is where I get directed. Is it possible that they have just dual labelled NMC and UF like THHN/THWN? They do seem to share a lot of capabilities.
Just my 2 cents but here in NJ all of the AG buildings do have to get permits and they are inspected. they do however get some perks from zoning boards and planning boards. An Ag building can sell "stuff" like fruits and vegs., and "etc." (like candles?) to make a profit. They can even sell propane. ( Is that a fruit or a vegtable?) We can only get them when they do electrical work.
Harold Endean,and all: regarding Propane, your Fire AHJ would probably be interested in the sale or use of propane in any significant quantities. Flammable compressed gases, and liquified petroleum gases, are most certainly regulated under the various Fire Codes.
Type NM-C is required for dairy barns and similar farm buildings according to my handbook. I don't think I have seen any of that around though.
I have wired a lot of horse barns in Kentucky.
I always use exposed UF cable and I always install it way up high so that ole mare won't chew into the cable or if the place needs a good wash down. Now rats and mice? Well there aint a barn in america that doesnt have a rat or church mouse hanging around all that extra feed that gets missed and all that hay makes a nice cozy little nest for the cold winter nights, but we can not install wiring based on the possibility that a rodent may decide that PVC is tasty enough to eat.
UF is an acceptable wiring method for homes, horse barns, garages, outdoor buildings and anything else outdoors or in wet/damp locations. It is a great cable if you ask me. I love the stuff!
Use UF cable or PVC.
Carlon boxes and raintite connectors are in order. I also use a mason jar type light fixture for the stalls and use Carlon FS boxes for switches and outlets.
[This message has been edited by mustangelectric (edited 12-07-2004).]