I was born and raised in a rural town in North Dakota called Bowman. Approximately 1,500 people lived in town, but many more lived on farms or ranches in the surrounding area. Many of my classmates in high school had parents who were farmers and ranchers. Whenever someone needed help due to illness, big chores or a cattle roundup, everyone would join together and give them a helping hand. As high schoolers, we were all involved in major cleanups for our friends and classmates—we shoveled out barns, cleaned out chicken coops and more. Now people pay money to vacation at dude ranches.

Changing my mind

These were great shared experiences, and while I have never regretted them, I became an electrical contractor in the Phoenix area so I would never need to be in a barn again. 

Then, when I had been an electrical contractor for about six years, I received a phone call from George in Scottsdale, Ariz. He had a major building project in Scottsdale and had heard really good comments about the electrical work we did. When I asked him what sort of project he was building, he explained it was an Arabian horse barn and auction facility. 

I told him we did not do electrical work on barns. He kept saying that he wanted only the best and had heard that was us. I insisted that I would not work in or on barns, and he insisted we should. Then he said the magic words: he would “pay us time and material on the project,” and I asked when he wanted me to be at the site. So much for commitments! 

We did all of George’s work for the next nine years. I have never seen such an incredible barn, with three chandeliers in the runway area outside the stalls and automatic waterers in the stalls. I hate to say it, but it was nicer than my home!

The auction facility was 40,000 square feet with an H-frame setup, Klieg lights for lighting the stage, a master dimmer control area for show lighting and a huge seating area. He hosted horse and car auctions, as well as rock concerts in the large amphitheater. 

Code requirements

The requirements in National Electrical Code Section 547.1 address the severe environmental conditions that regularly exist on agricultural premises, including damp and wet conditions, dust from feed and litter, and corrosive agents from livestock excrement. Agricultural buildings are areas where excessive dust and dust with water may accumulate, including all areas of poultry, livestock and fish confinement systems, where litter or feed dust, including mineral feed particles, may accumulate. 

NEC 547.1(B) covers agricultural buildings where corrosive atmospheres exist. Agricultural buildings include areas where poultry and animal excrement cause corrosive vapors or where corrosive materials combine with water. The areas are often damp and wet due periodic washing of the animals, barn and other areas for sanitation.

NEC Article 547 applies to agricultural buildings and similar, adjacent areas, such as George’s automatic horse exerciser, which had steel railings around it. It was in an area fairly close to some 500,000V overhead power lines. When I came out to install the power to the walker, the ferrous metal railings and the steel frame were inductively charged from the overhead lines. 

NEC 547.44 provides installation requirements for equipotential planes and bonding of equipment in these areas to remedy the problem. Grounding and bonding requirements unique to agricultural settings are necessary due to livestock’s sensitivity to slight differences in potential between surfaces and animals in direct contact with these objects. Any wet or damp concrete common to animal confinement areas enhances that sensitivity. 

We fixed the problem of the inductive coupling by relocating the walker to an area far enough away from the overhead power lines. We also created an equipotential plane surrounding the walker and the rails so we had zero difference of potential between all metal objects in that area.

I learned a lot about electrical installations in and around agricultural buildings and the critical electrical issues surrounding horses and livestock in those nine years. The horse barn and auction projects that George, my electricians and I accomplished together were very satisfying, and I look back on them with great fondness. Maybe I don’t mind barn work after all.

CASTENOID / STOCK.ADOBE.COM