Ph. Aupetit wrote:

Thanks Jim for your response, your opinions and comments are always valuable.

Unfortunately, I do not know enough about the ANSI standard to appreciate precisely the differences in the calculation of short-circuit currents with the IEC standard.

But, notwithstanding the standard for calculating short-circuit currents, my question is that if the source feeding the short-circuit is a current source (for example power station unit with full size converter), I would tend to think that the arcing current should be taken equal to the bolted short-circuit current as the short-circuit current is then independent of the arc impedance.

But what, in that case , of the reduced arcing current ?

Philippe Aupetit

Trace software International

Got it!

As far as the current, that makes sense. But if the current remains constant and there is arc impedance, that would result in a larger arcing voltage and I'm not sure how that is reflected in the model. I believe you hit upon one of the areas that was not addressed in IEEE 1584.

btw, this is just an informal opinion and may or may not not represent the views of IEEE.