At a fire a few years ago, I watched as 30' of 4" rigid and 3 500kcmil cables vaporized. This was on a 120/240 volt single phase servive. There was much less of the conduit left than what is shown in Bob's pictures. It was a great fireworks show for about 25 minutes. The 750 kva transformer in an underground vault got hot and the cables at the transformer were smoking, but the primary fuses never opened and the transformer was not damaged. Don
