in the over-engineering style of jacksdad we are dropping 200 amp service to the barn (to it’s own panel) and getting conflicting advice on the type of wiring we should use. i’m thinking armored cable, but i’ve read and had some folks tell me that i shouldn’t.
what’s your barn wired with and how’s it working for you? also, do you have any recommendations on lighting types/schemes? any big time stupid moves out there that i can learn from before i do them?
thanks in advance!
OK Jacksmom, here’s the scoop. I am a licenced master electrician on Long Island, and have been for the last twenty years. I do specialize in horse barns and horse facilities. And oh yeah, I’m a “he” not a “she”.
All of our installations are covered by the latest edition of the National Electrical Code (NEC), which is currently the 2002 code. Horse barns are specifically covered by Article 547, “Agricultural Buildings”. You can get a copy of the 2002 NEC from the National Fire Protection Association (NFPA). BUT it is not a simple document to understand. It is a legal document, not a how-to book. The study of the NEC in preparation for licensing is a seven-year process of apprenticeship and journeymanship. So you may want to save your money as it is pricey. It’s not rocket science, don’t get me wrong. But it has about as many different interpretations as the bible does.
Under Article 547, the only approved wiring methods are:
All boxes and fittings must be approved for the purpose ie, weatherproof boxes with sealed entries.
Notice, no rigid or thinwall metallic conduit permitted Also take note, no armored cable (called type AC, commonly known as BX) permitted.
The reason for this is that the environment of a horse barn has been deemed to be hostile to metallic wiring methods due to the damp conditions and the corrosive properties of the vapors urine and manure.
Also due to the presence of dust from hay, feed and bedding, all junction boxes and switch and outlet boxes must be weatherproof, as well as GFCI protected. All lighting fixtures must be rated as vaporproof. Which means, fully enclosed and gasketed (no bare bulbs of any type).
If you have more specific questions please PT me again. I have attempted to layout general information here only.
Incidentally, in the barns we wire, we use rigid PVC conduit, weatherproof PVC junction boxes and switch/outlet boxes, weatherproof PVC covers, vaporproof linear fluorescent fixtures or “bulkhead” type enclosed and gasketed incandescent fixtures.
I am well aware of the fact that when I make this information available, some people are shocked (no pun) to find out that metallic conduit is not permitted. Especially if they just had their barn wired that way.
May I say that:
a) The code is quite specific on this matter, and
b) The code is subject to interpretation by the “Authority Having Jurisdiction” (AHD), which is, the local electrical inspector.
c) I have heard that some inspectors in different areas do not treat horse barns (for some unknown reason) as Agricultural Buildings as defined in ASrticle 547. If they do not, they may treat it as an accesory building like a storage shed and as such almost any wiring method is accepted.
d) While I am much more involved in this area of the NEC than most electricians, and I beleve that my interpretations (which are the same as my local electrical inspectors) reflect the spirit of the National Electrical Code as it applies to the protection of livestock and the facilities that house them, YOUR INSTALLATION DOES NOT HAVE TO SATISFY ME, only the local authority having jurisdiction!
and further amplifying what armandh has posted, don’t put any part of the electrical system inside a stall or where inquiring teeth can reach it. I have seen conduit pulled from the wall by a horse. Any stall lighting has to be above where a horse can reach.
Farmdad/Tom,
I’m very interested in what you have. I’ll be doing much of the barn electric myself.
tcgelec, if you run the wire in conduit, can you use the TNNF wire? (I hope I remembered the letters correctly)
My barn is coming today and tomorrow (modular barn) and the crew to finish will be here around July 12th! I’m just a smidgen excited.
Mel
in the over-engineering style of jacksdad we are dropping 200 amp service to the barn (to it’s own panel) and getting conflicting advice on the type of wiring we should use. i’m thinking armored cable, but i’ve read and had some folks tell me that i shouldn’t.
what’s your barn wired with and how’s it working for you? also, do you have any recommendations on lighting types/schemes? any big time stupid moves out there that i can learn from before i do them?
thanks in advance!
Kestrel:
I can’t say if metal conduit is or is not a bad thing, but it does not meet the National Electrical Code when used in horse barns. Each code article has a code-making panel, and the codes evolve over years and years of evaluting input from people involved in that specific area of the industry and that is how new regulations develop.
Armandh:
I have never seen a horse break a piece of PVC conduit that was properly installed and supported, and placed thoughtfully so that a horse would not be apt to chew it. Two thicknesses are available, Schedule 40 and Schedule 80. Sched 40 is by far the most common.
Sched 80 has much thicker walls and is used in severe service or for other special purposes but nothing would prevent you from using it in your barn if you had concern about strength.
There is no designation between residential and commercial in Agricultural Buildings. So called “residential” articles of the code pertain only to dwelling units. Ag Buildings are considered “special occupancies” and have their own article.
You are correct, there is much disparity between municipalities in adopting and enforcing electrical codes. Some towns have not officially adopted the NEC, some have their own codes (like NYC for example) and some have adopted the NEC but have no mechanism to ensure compliance.
Your best bet is to hire (or at least talk to) a local electrician who is familiar with barns.
It might interest some people to know that Pennsylvania does NOT license electricians. Some localities in PA license electricians (Philadelphia, for example) but, basically, in PA you can hire anyone you choose to wire your barn or house. It is the “homeowner’s responsibility” to hire someone competent. (Yes, I was told that by a code enforcement officer.)
Furthermore, in at least some areas of Pennsylvania, agricultural buildings require NO PERMITS and NO INSPECTIONS. (This will apply to Oxford Borough starting July 9, 2004.) If the area “disturbed” by the building is less than an acre, you do need to file a sedementation and erosion control plan, however.
Anyway, it makes barn building pretty easy, but the idea of BUYING a barn years down the road & not knowing how it was built or what you are getting scares the living daylights out of me!
armandh - jacksdad is a ‘going all out’ kinda guy. he’s also a perfectionist. which is nice, unless you want to do something quickly 
his greyness - good idea. since the wiring is going in before the stalls it should be fairly easy to build it in. i have a 10 foot ceiling so i’m not worried about the horses getting to the fixtures. i’ve seen what an exposed lightbulb running into a horses head can do and it ain’t pretty.
tedshel - that’s exactly why i was thinking armored cable.
please folks keep the advice coming!
i got some GREAT advice from everyone when i was designing the barn - ‘to think of the biggest barn i might ever need and build it even bigger’. so far i don’t have a horse in it yet (fences first) but i am loving the space to stage all of the other projects.
It would be nice to run everything concealed in the barn…even build a wireway up at the ceiling, etc. so it is completey out of reach of any live animals. Your electrician will know the code and just make sure to remind him that horses can chew through just about anything.
I HIGHLY recommend fluorescent lighting. A nice linear (think about 7-12" wide, 4’ or 8’ long) fixture surface mounted (or suspended, depending on ceiling height) running the long way down the aisle looks great. Wireguards are always a great idea in the barn as well.
(The pros of fluorescent: lower wattage = less money to run, more energy-efficient, and less heat = less fire risk)
BX wiring (metal encased) is great for any area the horses can reach. Its easier to install than conduit.
We prefer incandescent over fluorescent and discharge-type fixtures for indoor use due to slow warm-up and cold-weather problems. We use the heavy-duty drip-proof (Nema 4 or 3R) fixtures with screw-in globe and wire cage.
We also use 130-volt instead of 120-volt bulbs to increase life.
There is a plastic-coated rigid conduit for use in corrosive atmospheres, but it’s very expensive and requires special installation. techniques.
There was a study performed quite some time back concluding that fluorescent and discharge-type fixtures created stress in animals because of the rapid flickering. A client was building a farm animal research facility, and insisted on incandescent fixtures because of it. I have long since forgotten the details since that was in the early '90s.
You should PT TCGELEC. He’s an Electrician that does horse barns. He’ll give you advice.
On the plastic versus metal conduit:
Our barn has been built in stages over the past 24 years. The first part was with EMT (electrical metallic tubing) and the later stuff in plastic. The building code might say plastic is required but we have 2 broken pieces in the plastic part and no damage to the metal part. No one has ANY idea how the plastic tubing got broken. I would ask your local electrical inspector and use metal for the drops if possible. Plastic is so much easier to use and I see no problem with using it any place where it is out of harms way–such as the lighting circuits and the main horizontal run up high with something like 1 1/2 inch plastic with 1/2 inch metal drops.
For any EMT that you use ABSOLUTELY be sure to deburr the inside of the ends so that no wire insulation gets damaged when pulling wire.
Let’s look at the potential problems with EMT from a safety standpoint. I’m sure someone somewhere has been electrocuted by damage to the wiring system or improper installation by the metal tubing itself. The danger of this would be if a “hot” wire were touching the EMT without a it being “grounded” to the ground wire. Okay, so let’s come up with a way to make the setup safer. I would run the ground wire as bare conductors through the conduit system. I use double boxes for the receptacles and leave a lot of extra ground wire carefully coiled around the inside back of the box several times and securely fastened to the box itself as well as the device (receptacle). Then if for some reason the hot wire was jerked loose from a connection and touched the EMT the possibility of the ground wire not also touching the EMT would approach zero. This would trip the breaker. I’ve never seen anyone use NM or UF wiring inside conduit. I use single strands of “stranded” black, white, & red for the conductors and solid bare for the ground.
For receptacle boxes inside the horse area of the barn I would use the double boxes and either use the double size plates with one receptacle in the center or go ahead and put the two receptacles in. I don’t like the little doors on the weather-proof covers because one will always get broken off leaving a sharp point or spring end sticking out. I like to put the little “child-proof” plastic plugs in the unused recetapcles to keep insects from using the holes for nests. I know this is not weather-proof but have no need to spray water directly into a receptacle inside the barn. Just keep extra plugs in a drawer in the barn.
I like the double boxes because they can be fastened much more securely than the single boxes. Don’t use the little ears on the sides of some boxes. Drill holes in the inside corners of the boxes and fasten them with #12 sheet metal screws of a maximum length that will not protrude through the other side of the wooden member it is fastened to. I wouldn’t use decking screws because they are not as strong and the heads pop off too easily. Regular wood screws don’t have threads the entire length and it’s hard to find good quallity ones now anyway. Sheet metal screws have threads the entire length and hold fine in wood. Four in the corners of the double box will give you a very strong mount.
On the EMT itself put plenty of straps and don’t use the kind that have only one screw on one side. Use the type that have a screw on each side.
For the devices themselves don’t get the cheapest kind. I like devices made by Pass & Seymour. This stuff can be bought at electrical equipment suppliers for less and with better quality than the run of the mill stuff you see in Lowes. Get a new screwdriver that fits the slots in the devices and don’t use it for any thing else.
For all wire to wire connections on the ground wire get the little metal sleeves called “Sta-CONs” and the special pliers for them to securely crimp them on the twisted together wires. Don’t use wire nuts for this. We already talked about how important the ground circuit is.
When you put conductors together with wire nuts twist the wire together securely counter clockwise, cut the excess off with the lineman’s pliers, and screw the wire nut on. Make sure there is no exposed bare conductor showing outside the wirenut. The kind with the little wings out 2 sides work better than the kind with the knurled sides. You will need some red wirenuts and some yellow ones. They are color coded for size.
Tools you will need: Lineman’s pliers ( to cut wire with and make pretty twists with), good screwdrivers, special pliers (with one orange and one black handle)for Sta-Con’s, needle nose pliers to shape the ends of the conductors to fit around the screws on the devices (don’t back wire them), a long bit for your drill to run the screws that hold the boxes up so that the drill chuck won’t interfere, wire strippers to fit the size wire that you will use,tubing cutters for both the EMT and the plastic. Lowes has a good tool section in their electrical department. If you will only be doing your own work I wouldn’t go to the expense of buying a Fish Tape. They are nice to have for pulling wire but for one job I would just use a shop-vac to suck a string through with a little rag tied to it. Buy the types of elbows and tees that have the screw on covers to help with routing the wires.
You will find that the EMT doesn’t fit inside the plastic fittings. If say you use 1 1/2 plastic for your main runs and drop down to 1/2 EMT to go to your boxes you will need to use plastic tees that the 1/2 EMT will go into and use silicone caulking to fill the void around it.
All this might not be okay with your local inspector. Ask first. I asked my inspector if he wanted to look at my barn wiring. He asked who did it and when I told him that I did he said he didn’t need to bother.
I probably left something out but if there are any questions I will be glad to answer them.
wow folks - GREAT stuff.
where we are there are no inspections required for agricultural building wiring. scary but true.
we have a copy of the current code book and jacksdad has taken several courses on residential wiring at the local community college (he was considering becoming licensed).
we’ve already corrected some very dangerous wiring schemes in our little house that was installed by ‘professionals’. i think we have a leg-up on the average do-it-yourselfer.
farmdad - please contribute - we are trying to do as much of this ourselves as possible.
tcgelec - thank you for the great info! i’m printing everything out and passing it to jacksdad. you might find it interesting that the instructor for jacksdad’s last class was a female master electrician, and a damn good one at that 
Okay don’t quote me on this - if I remember, we dropped a 300 amp service to the garage and peeled off 200 to the new barn. We’re mainly using 14 to wire the barn. Lots of GFI outlets.
We’re following the latest and greatest code book.
Tom,
Thanks for going to the trouble of writing that up. I’ll be printing this out.
The first modular section of my barn came today. The next one should come tomorrow…then the materials to finish it on Thursday.
I have my water in their, but will need to run power. I’ll be having my electrician do the panel and get me up for my service inspection, but from there, we will likely be doing it on weekends, the old DIY method.
Mel
I have a lot to add but not enough time right now. We have a house full of company–one of the benefits/problems with living at the lake on a holiday weekend.
My information would mostly be for the do-it- yourselfer. If any are so inclined please say so or I won’t bother. No bother if anyone needs the how-to information.
The wire you will pull in the conduit is called THHN. There are others approved for use but this is the most common.
You can use EMT (electrical metallic tubing) for a very nice, durable, professional, and in my opinion, safe installation. I used to do it myself before the code change some years ago. It’s just that, being an NEC violation, it won’t pass inspection, around here, anyway. In my area, electrical inspections are not done by building inspectors. They are done by a completely seperate entity, which is certified by the local municipal governments to do electrical inspections on their behalf. We use an entity called the New York Board of Fire Underwriters, which was created by a consortium of fire insurance companies around the year 1900. The inspectors for this agency are specialists in the National Electrical Code, and as such are fairly strict in their interpretations, and are kept up-to-date on changes. After a successful final inspection, we are issued an Underwriter’s Certificate, which we give to the owner, who presents it to the local building department after all other building inspections have been done, in order to get a Certificate of Occupancy (or Certificate of Use) for the barn, after which it is legal to be occupied and used.
We are in the NY Metro area (Long Island) and building/electrical/plumbing codes tend to be rigidly enforced, to the letter of the law, so we do our installations to comply with that. We also don’t usually get paid until we produce an Underwriter’s Certificate, and I have horsey mouths to feed!
Incidentally, in show barns we sometimes put in supplemental fixtures in the stalls with 200 watt bulbs on a timer to “fool” the horses body into not growing a winter coat. These are also used by some to stimulate the estrus cycle in breeding barns.
I stand corrected. this must be new since ours was built, but PVC conduit is easier anyway just cut/glue. but it is more easily subject to damage than heavy wall steel [other than corrosion] as I look at our barn I note that everything that is below 6’ high is PVC. above done in thin-wall steel conduit except drops to lights in BX. no corrosion yet. too true it is the local inspector that decides. also the differences between residential and commercial may come in to play.
tcgelec,
Thank you! THHN, THOSE were the letters I needed.
Mel
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