It's Simply Shocking!

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There are many electrical problems that can arise around a farm that put everybody at great risk. What can you do to protect both equines and humans?

Electricity Explained

First, a simple explanation of how electricity works is helpful. To understand the process, think of a three-pronged outlet. There are two parallel holes and beneath those, a round hole. The electricity flows through one of the top holes, into an apparatus, and then out through the other top hole into the wall. The round hole serves to ground the outlet; it protects the system so if something happens to the neutral wire (the wire returning electricity to the outlet) the electricity will flow through the ground wire to prevent a shock.

It takes surprisingly little electricity to cause injury, and the danger is measured in milliamperes, not amps (1,000 milliamperes to an amp). Less than 15 milliamperes will cause a painful shock and, explains Dr. Philip Chumbley, the Director of Research and Development at Allied Precision Industries in Elburn, Ill., it can take “…as little as 20 milliamperes passing from one arm through your heart to kill you. To put that into perspective, a 100-watt light bulb draws almost one amp of electricity, and 10 milliamperes is just 1/100 of that.”

Combine the danger with a farm environment, and you have the makings for a disaster. “Farms are hostile environments for electricity,” continues Chumbley. “Many barns have old electrical boxes, and I’ve seen birds build nests around them and rodents get electrocuted. The proximity to water and combustibles adds another level of danger: hay, dampness, dust, wet ground, electrical fences, and equipment running outdoors increases the danger.”

Going Astray

Electricity leaking from heating elements used in bucket deicers is a common cause of shocks. Purchase units that are double-walled, with the heating element wrapped around the outside of the inner bucket. This keeps the unit away from curious equine noses. When heating elements are inside the bucket, they can crack and allow electricity to flow into the water. “Never,” cautions Chumbley, “stick your hand into the water if you suspect it is shocking your horses. It is the first thing everybody does and is very dangerous. Get a voltmeter and test the water safely.”

All new heaters must have a ground wire to prevent any chance of shock. But, says Chumbley, “A problem arises when things are not hooked up correctly. Buildings that were built before the electrical code called for a ground wire have outlets without the third hole. People buy a device that has the ground pin on it, but because their outlet only has two holes they cut off the ground pin. If you plug the device in, it will work fine but now the safety backup has been removed. So, if the unit fails, you have no backup and you’ll get shocked. Also, if there is a path to the ground through a metal rod or perhaps a tool next to the outlet, then it could get hot and start a fire.”

Every outlet should be fitted with a Ground Fault Circuit Interrupter (GFI or GFCI). They are required in all new construction, but many old barns have not been updated. GFIs look at the current flowing out and flowing back through an outlet. If the numbers are identical, nothing is done. However, if there is a short, say 5 amps is being sent out and only 4.5 amps are returning, the GFI will shut the outlet down. It is, however, not a perfect system, because GFIs don’t look at the ground wire. That means if you have a voltage leaking to the ground wire, the GFI won’t see it. However, at about $12 per unit, it is an inexpensive safety precaution.

Get Grounded

Even the best planned systems can malfunction if not correctly grounded. If you don’t have a proper grounding rod, then electricity will find another path to the ground. A grounding rod is a copper rod, about eight feet long, buried to a depth of at least seven feet. Electricity will flow through the path of least resistance, and electrons travel much easier through copper than flesh.

If your electrical box is in one section of the barn and your horses are in another, what do you do? “This could be a problem,” admits Chumbley. “There can be a bit of a difference in the ground potential between the box and where the horses reside. That means the animals could get shocked as they are at a different voltage.

“One solution is to put your grounding rod as close to your water tank as possible and ground your system there.” Do not, cautions Chumbley, simply install two separate grounding rods. “What can happen,” he explains, “is that instead of working as grounding rods, they now have the opposite effect and work like antennas. Also, don’t use your electric fence grounding rod for your circuit, because electric fences can be bad about leaking current over to the ground wire.”

Electrical problems may also originate off your property. “You could have a farmer across the road who is running an old motor that leaks current,” notes Chumbley, “and that current can travel right across the road to your property. So, even if your own system is properly grounded, there is enough potential that you can get some voltage on your ground wire.”

Utility Companies

Debi Bois of Landrum, S.C., had a plumber install automatic heated waterers in all of her pastures recently. “I noticed the horses would approach the waterers but as soon as their whiskers touched the water, they would lift up without drinking. I put my hand in the water and couldn’t feel anything. [Editor’s note: never put your hand in water you suspect may carry a charge, use a voltmeter!] The plumber returned and noticed about seven to twelve volts running through the water.” Bois called the power company and they discovered that because the farm was at the very end of the power grid, they were getting unusual electrical feedback through the lines. “Not enough to hurt us,” notes Bois, “but enough to keep the horses from drinking. The power company’s solution was to dig a trench around each waterer and lay a ground wire all the way around each unit. Now, when the horses drink they are on the same conductive level as the feedback and don’t get shocked.”

How will you know if the stray voltage is coming from the power company? “You may not,” warns Chumbley. “So test your own circuit first. Then call the power company.”

Extension Cords

One of the most overused pieces of equipment on farms is extension cords. At the very least, all cords left near horses should run through anti-chew springs or conduit.

In addition, “People tend to overload extension cords,” says Chumbley. “If you’re using a 1,500-watt de-icer that draws 12.5 amps, that means you can’t put two of them on a 15-amp circuit or even a 20-amp circuit. Add to that a 100-foot extension cord and you get a voltage drop along that cord. Now, instead of 1,500 watts, the extension cord may only be delivering 1,200 watts.”

Electrical problems may seem too complicated to address, but it is imperative that you don’t ignore what could become a life-threatening problem. Buy a voltmeter and get in the habit of regularly checking your system.