Why are Some Colored Balls Mounted on High-Voltage Power Lines?

Aerial Marker Balls and Balisor Attached in High Voltage Power Transmission Lines

If you come across a high-tension overhead power transmission lines conductor, some colored balls hanging on those conductors will catch your eye. Seeing them, you must also have a question what is their usefulness? Are they applied just for decoration? So the answer is no. Neither are they applied for decoration nor do they have anything to do with electric transmission. Actually, they are used for the safety of aircraft.

What Is Aerial Marker Ball?

The colored plastic balls hanging on overhead electricity conductors are called aerial marker balls. They are installed along the length of transmission line conductors that are normally not visible enough to act as a visual warning so low-altitude flying aircraft like helicopters don’t run into them.

These colorful balls are colloquially called "marker balls" and are used to protect from crashes of low-flying aircraft and helicopters. Using these blinked aerial balls onto high voltage transmission conductors, actually makes it visible to the pilot from significant distance wires are clearly seen by the pilot. Although you may not have realized it, these balls are commonly used on mountain roads, deep valleys, major highway crossings, and airports. These are all places where aircraft fly at low altitudes, which causes them to get angled in these wires.

These aerial balls are proving to be very beneficial not only for aircraft but also for birds. Migratory birds coming from faraway countries can easily see high-voltage wires with the help of these balls and avoid getting entangled in them.

The story of the arrival of these balls is also very interesting.

In the 1970s, when the Governor of the US state of Arkansas "Winthrop Rockefeller" was about to land the plane, he noted that the wires next to the airport could prove to be dangerous for the aircraft and some measures should be taken that That the pilot of the aircraft can see these wires clearly.

Since then these balls have come into vogue.

What Is Balisor in the High Voltage Power Transmission Line Attached?

There’s also something called a balisong, which is actually a system of glowing beacons that use low-pressure neon lamps positioned along the length of high-voltage power lines. The system is extremely simple, efficient, and reliable and is considered the most economically viable solution.

The screenshot is owned by OBSTA.

A typical balisor is just under 1 meter long and the capacitor is formed from a conductor about 4 meters long.  The operating principle is fundamental.  As the voltage in the line parallel to the balisor conductor rises or falls from zero the capacitor charges.  When the voltage across the neon lamp reaches the striking voltage of the neon it illuminates.  When the voltage falls below the discharge-sustaining threshold the light is extinguished.  The voltage rises and falls 50 or 60 times per second, so the neon illuminates 100 or 120 times per second.  To the human eye, it is permanently lit.

Its working principle is attractive because it uses a phenomenon usually considered a weakness. However, a large disadvantage is that it does not work when the line is switched off. It cannot also be used on HVDC power lines, but similar devices may be also used on mast radiators.