Safe distance of high-voltage line

Safe distance of high-voltage line. What is the safe distance?

In order to prevent the human body from touching or approaching the electrified body, and to prevent the vehicle or other objects from colliding or approaching

the electrified body causing danger, it is necessary to keep a certain distance from the electrified body, which becomes a safe distance.

How many meters is the safe distance?

Remember: the greater the voltage level, the greater the safety distance.

Take a look at the following table. China’s Electric Power Safety Work Regulations give the safe distance between personnel and energized high-voltage AC lines.

Minimum safe distance from overhead transmission lines and other charged bodies
Voltage level(KV) safe distancem)
1 1.5
1~10 3.0
35~63 4.0
110 5.0
220 6.0
330 7.0
500 8.5

Is it absolutely safe without touching the high-voltage line?

Ordinary people will mistakenly believe that as long as their hands and bodies do not touch the high-voltage line, they will be absolutely safe. This is a big mistake!

The actual situation is as follows: even if people do not touch the high-voltage line, there will be danger within a certain distance. When the voltage difference is

large enough, the air may be damaged by electric shock. Of course, the larger the air distance, the less likely it is to be broken down. Sufficient air distance can

achieve insulation.

Is the high-voltage wire “sizzling” discharging?

HV transmission tower

When the high-voltage wire is transmitting electricity, a strong electric field will be formed around the wire, which will ionize the air and form corona discharge.

So when you hear the “sizzling” sound near the high-voltage line, don’t doubt it is discharging.

Moreover, the higher the voltage level, the stronger the corona and the greater the noise. At night or in rainy and foggy weather, faint blue and purple halos may

also be observed near 220 kV and 500 kV high-voltage transmission lines.

But sometimes when I walk in the city, I don’t think there is “sizzling” noise in the electric wire?

This is because the 10kV and 35kV distribution lines in the urban area mostly use insulated wires, which will not produce air ionization, and the voltage level is low,

the corona intensity is weak, and the “sizzling” sound is easily covered by the surrounding horn and noise.

There is a strong electric field around high-voltage transmission lines and high-voltage power distribution devices. The conductors in this electric field will have

induced voltage due to electrostatic induction, so the more brave people have the idea of charging mobile phones. It’s terrible to have culture. This is a series of

death. Don’t try it. Life is more important! Most of the time, if you are too close to the high-voltage line.


Post time: Jan-30-2023