You gotta see this.
http://205.243.100.155/frames/longarc.htm#500_kV_Switch


Rob

Damn.... the second video of that sub-station going up in flames is incredible! Scary stuff.

WOW !

Cool stuff, thanks for a great link.

Lost for words, impressive video clips. thanks

From what i have understood from my classes is:
In order to open a high voltage and high current switch it must be done extremely fast and the blades of the switch must be rounded. and when closing one it also must close fast.

Right?

Edward

Edward,

Exactly right. This was discussed in this thread https://www.electrical-contractor.net/ubb/Forum1/HTML/006650.html

The open air links that you see moving slowly are _not_ supposed to interrupt the load, and are not suitable as a switch for these high voltages and currents. The actual switches are in what appear to be insulators on the right hand side of the assembly. One of these failed to open, leaving the visible moving bits to open the circuit...which by demonstration they cannot do.

-Jon

Some notes on that video:

The failure started as stated on the "low voltage" side of the sub, supposedly with a capicator bank failure;

It was not cleared by the substation's protection relay scheme because a $20.00 fuseholder for the relay failed. (That particular brand/type of fuseholder was found to be a problem at substations all over the U.S.);

The boiling oil being shot out of the pressure reliefs caused the major fireball near the end of the video; (it looks like water but there were no firefighters anywhere near that thing during the arcing fault phase)

The blue flash and loud bang is the transformer's expulsion fuse filally blowing and killing the power.

Now after seeing that video how would you like to live next to a substation? I have a friend here in So Cali who lives next to one and he tells me the noises coming from the sub as breakers and reclosers operate during an earthquake is the stuff of nightmares.