bird

[rajic007]

Explain why a bird sitting on a 400 kV power transmission cable is not electrocuted

[wildwood]

No Earth

[Clachair]

It's not the voltage which will electrocute them, it's the electrical current, which has to have a return path through a body to cause muscle dysfunction etc.
Birds probably feel a very slight tingle through their feet as they land on the wires, due to a small static charge.
It would be different if they were big enough to straddle the two wires. Raccoons sometimes fall for this one on utility poles, and get very badly burned.

[sddsddean]

Obviously it is wearing wellies!

[chakka35]

In a 400kV transmission line, Clachair, what do you mean by "the two wires"?

[kujawski]

cos theyre made of rubber

[Teddio]

Most pylons carrying power lines at a pd of 400 kV are arranged in 6 groups of bare aluminium cables, air being the insulating medium. The power is transmitted as a three-phase supply and every set of cables is live. Each set usually comprises two or even four cables connected together with spacer bars. Any bird sitting on a cable will have every part of its body at the same potential and therefore no current will flow through it. Birds rarely sit on live power cables as they will feel an uncomfortable static tingle. Instead they prefer to sit on the thin overhead "return" cable on the top of the pylon.

[nix-j-c]

because you only get electricuted if you touching the ground without non conducting material between you and the ground and the wire so theoretically if you fly a kite and you jump when the kite touches the wire you shouldnt get electricuted i think.

nix-j-c

[tufty7]

Don't try the above at home kids........