Individuals who have worked on or around power lines know that they must work with extreme caution. The risk of dangerous and even fatal electrical shock cannot be taken lightly, which is why crews must wear protective equipment and follow rigid safety guidelines. However, these workers also must have looked at those same lines that they have been trained to regard as a lethal threat and seen a flock of small birds perched on them.
These feathered friends seem to have no trouble sitting on these high-voltage wires than they do the branch of a tree. Why don’t birds get electrocuted on power lines but humans do? The answer lies mostly with the nature of electrical current and partially with birds’ blissful ignorance of the potential danger.
GOING WITH THE FLOW
Simply put, electricity doesn’t go anywhere unless it has a closed loop made of conductive materials with at least two points of differing potential. That means the number of electrons at one point should be lower than the starting place. Electricity seeks to balance that, sending a charge from the point of higher potential to the lower one. The earth itself has a voltage of practically zero. It is almost always the lowest potential. Because the energy tries to get to the ground, anything that gives it a circuit through which it can flow to the earth will become energized. For a living being, that’s bad news.
Birds, however, have found a kind of loophole to this natural law. Because they can fly, they can land on a power line from above, never coming into contact with the ground or anything else as they do. This is crucial, because their feet have the same electrical potential, which means the electrons flowing through the line they’re touching don’t need to make a detour through them.
This protects the feathered creature from receiving a shock. However, if any part of the bird’s body were to come into contact with something that had a different potential, such as the pole, the charge would find a way to the ground and zap it into oblivion.
Humans, on the other hand, are standing on the ground or in a cherry picker when they come into contact with power lines. This means that without the right precautions, they will be in connection with the ground directly or indirectly. Either way, they create a circuit that leads to severe electrocution risk.
This is why protective gear such as EPZ grounding grates from YAK MAT are so vital at work sites. Made from all-in-one galvanized steel grates, these create an equipotential zone where they are placed. When standing or walking on them, the electrical potential between any two points on a person’s body is virtually equal. This allows him or her to take advantage of the same basic effect that protects birds that sit on energized lines. Any current that happens to flow into this area will be directed via the grate instead of through the people standing on them.
This article is contributed by YAK MAT. YAK MAT is the largest supplier of access mats in North America, specializing in providing access solutions for energy products. Pioneering the industry since 1976, YAK MAT offers clients economies of scale and a variety of ready to ship construction protection mats in close proximity to any project, anywhere in the United States.