More Arcs ‘n Sparks

February 22nd, 2007 by Guppy Leave a reply »

480V arc flash

Bert Hickman’s site, Stoneridge Engineering has a great page featuring high energy electrical failures and phenomenon. Along with video of an exploding transformer substation there’s the world’s biggest jacob’s ladder and an awesome demonstration (pictured) of high current, low voltage arcing:

The thermal energy liberated within a high current arc can be many tens of megawatts, and the arc core may reach 35,000 degrees F (four times that of the surface of the sun!). As the arc “roots” vaporize portions of the copper bus bars, the vapor explosively expands to over 60,000 times its solid volume. It then combines with oxygen in the atmosphere, forming dense clouds of copper oxide that blacken the air and nearby objects. Globules of molten copper are also violently ejected, showering the immediate vicinity with 2,000 degree droplets that can approach speeds of 700 miles per hour. Magnetic forces propel the arc along the bus, extending it in the process, and magnetic forces on the bus bars and cables may be sufficient to cause significant mechanical damage, possibly creating additional shrapnel.”


Comments are closed.