[Physics] Can touching a single power line (on the street) kill you

electricity

Statement: You need to touch two power lines at the same time to get electrocuted. I am kinda doubting this now because, in the video linked below, it looks like the person is only touching one line but still gets an electric shock. Is this possible? and also the person is on a tree and aren't trees insulators? This video isn't sensitive or anything, it actually funny, so please don't hesitate to watch. Thanks!
Video

Best Answer

Unless there is sufficient insulation (electrical impedance) between you and the earth when you touch a high voltage wire, yes you may get electrocuted. This is because most electrical power systems in the world are earth grounded (referenced to earth). The higher the voltage the greater the impedance to between you and earth ground needs to be. At 60 Hz it only takes 50-100 mA of current in a path through the heart to cause ventricular fibrillation.

If you are isolated from ground and touching two wires with your bare hands, electrocution is possible if the voltage difference has the potential to cause a lethal electric shock and the insulation on the conductors is insufficient to limit the current to below the threshold for a lethal electric shock.

oh okay, bats die when they hang on the cables, but they do not provide any connection between live and ground, how is this possible?

Regarding your above comment to Solar Mike, it is ONLY possible for the bat to be electrocuted if the bat is simultaneously in contact with the high voltage wire and another wire or grounded object where the voltage between them has the potential to cause a lethal electric shock.

Bats are physically different than the typical birds you observe on HV wires. For one I understand they may have wingspans much larger than ordinary birds. So if they are on a HV wire and spread their wings, there is a higher likelihood that their wings will simultaneously contact more than one HV wire at a time, or some grounded part, causing lethal electric shock. Regardless of the reason for their deaths, they must simultaneously be in contact with two conductors with a potential difference capable of causing a lethal electric shock.

Hope this helps