I have witnessed a Series Arc bridge a gap, which grew up to an Inch or more - in a very hot environment, with minimally conductive surrounding Air, and a potential of 230 VAC (measured after the event).
The bottom Element of an Electric Oven failed while in use, resulting in a Series Arc between the severed ends of the once continuous Heating Element.
When the Element failed, the established Arc could be faintly heard. My Mother and I were standing near the Oven at the time, and did not think too much about the sound - as it was similar to "Bubbling".
After about 15 - 20 Seconds, the sound became less "Bubble-Like" and more "Flame-Like", and the Oven Door was opened.
So Mom opened the Oven Door, only to be presented with a Fat Arc at the bottom Element (scared the heck out of her!!!).
Like the clown I am, I watched the Arc for a few seconds before turning off the Oven (via the Temperature knob).
That was impressive!!! Never thought such a large Plasma would be sustained across a Resistance Element, at a Potential of 230 VAC!
Element was (AFAIK) 4500 Watts, so there would have been at least 19.57 Amps flowing through the Element at the time of failure.
Arc was across the Element only. No L-G Arcing was evident.
-- Scott
