From childhood we are accustomed to the fact that you can not touch the bare electric wires. But why birds can sit on wires, and the life of birds does not threaten anything? Explain this clearly and simply does not work – because the birds avoid high-voltage lines. Let us nevertheless recall a little school physics and understand the nature of the phenomenon.
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A living creature, which the bird is also, can be killed by an alternating current of less than 0.1 A at a voltage of only 40 V. It seems that the classic 220 V for death of a bird is definitely deadly, not to mention higher rates. The current refers to the directional movement of electron particles between two points with different potentials. In order for the bird to die, it is necessary to put a strong current through its body. In other words, it should become a conductor between two points with different potentials.
But, sitting on the phase wire, the bird turns into its branch, connected in parallel. The potential difference between the paws of a feathered creature is scanty, and the resistance of the body of a living creature is much greater than that of a wire. As a result, a current flows through the bird, but it is negligible.
However, the wires are not at all safe for birds. If, while sitting on a phase wire, a feathered creature touches the grounded metal part of the supports, then the picture will change. In this case, so much current will pass through the bird that it will literally instantly incinerate it. This could have been avoided if the wires were insulated rather than insulated from the supports. But rare cases of bird deaths do not affect the power supply system, and the complication of wire production technology is a very expensive undertaking.
But the wires going to the houses, lanterns, poles already have insulation along the entire length. But there the current does not flow so much. Such wires are definitely not afraid of birds, although they protect people first of all.
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Birds and high voltage lines
However, birds do not sit on some wires at all. The thing is their sensitivity to magnetic fields. They just appear on lines with voltages above 200 kV. Yes, and the electromagnetic field generates corona discharges, leading to ionization of the air. This state of his birds also do not like. So the natural flair helps birds to choose perches in the air.