I think I have something to contribute here.

I've done bench test testing of gear for a major testing lab, and one of the tests involves applying high voltages to terminals in equipment. If they're too close together, or the barriers aren't adequate, you can see the arc jump across the space from one terminal to another. Why do you think 480v gear is so much larger than 240v gear if the same amperage rating?

Likewise, I have seen the reasonably high voltage created by a car's HEI coil run along the surface of the coil wire, then jump across the 1" (or so) distance through dry air to make contact with a rubber fuel line.

There are also a number of documented PoCo accidents, where an arc jumped between substation gear when equipment, or personnel, filled the space between things. Oops.

Then there's everyone's favorite science project, the Jacob's ladder. Mine was making 3" arcs before it broke; the arcs started by jumping a 3/4" distance.

That electricity can jump distances, and that the distance is dependant upon voltage, is pretty basic science.

As for qualifications ... I'm not impressed. I never have been. An argument ought to be able to stand on it's own merits; ever great discovery was made by a nobody - Newton and Einstein were 'nobodies' when they put forth their theories. The "Greats" of their days are now largely forgotten.

ECN is fairly unique in the internet world, in that it has a great variety of professionals here. Master electricians to handymen, associated trades like engineers, linesmen, and inspectors.

And that's the key; "associated" trades, rather than any sort of system of 'rank.' I am endlessly amused at the ignorance of folks who think an engineer 'outranks' an electrician. That's a lot like expecting a 'mechanical engineer' to fix your car. Lots of luck with that!

I'll soon have the opportunity to work with some seriously high voltage. I look forward to the training. While I can make some guesses, I'm sure not going to look to a general internet forum for lessons! Discharging capacitors and grounding lines are basic skills in some areas, and if someone hasn't already been taught, I have some trouble telling them anything more than: stay away!

Squirrel, you're not the only one here with lines qualifications, nor the first to have gone through engineer school. You can 'bare hand' HV? Impressive - but can you fly the helicopter too? At least one of the posters here can. So make nice.

End of sermon.

Last edited by renosteinke; 01/25/10 01:29 PM.