line open under load

[el dub]

https://www.youtube.com/watch?v=vqgNrj6oEdc&feature=player_embedded#t=2

[Patronus]

We were part of a demo crew at an old electrical plant. Had to cut up 8" conduit filled with copper wires.
My friend grabbed the demo saw and cut into the pipe. Flame shot out the end of the pipe and I turned around to see an explosion like that about a half mile away by the draw bridge.
He went home.

[Chargerguy74]

We had that happen at my old powerplant. An operator locally opened 240KV (now 500 KV) disconnects on an online unit, he was supposed to open them on the offline unit. Normally the generator breakers would be open before the disconnects, and closed after. It's normal to see some arcing, but nothing like this lol. I'd be crapping my pants if I was in that switchyard. If the air system to the airblast breakers fails, the disconnects should fail open as well creating a similar situation. Most of our breakers are SF 6, and not air anymore.