
Originally Posted by
lukemcg
From what I've read on a few different copies of that video, its a pump up circuit breaker, you basically pump it/wind it up until its ready to make contact and bang, its cranks on (you can see the guy cranking the handle)
Apparently there was moisture between the terminals and once it made contact it exploded, and the arc was so large that it sustained itself until the high voltage protection operated (outside in the substation) which is the constant flaring you see. Wouldn't have done the dude any favours though.
Really high current, could possibly be high voltage as well (in excess of 1000 volt).