Ok here it is in a nutshell,
Chapter 1 section 1.4.6 of the IEEE green book,
It says, because of the reactance of the grounded generator or transformer in series with the neutral circit, a solid ground connection does not provide a Zero-impedamnce neutral circuit. If the reactance of the system zero-sequence circuit is too great with respect to the system positive-sequence reactance, The objectives sought in grounding, principally freedom from transient overvoltages may not be achieved."

My question is what in the world is a zero-sequence circuit and the positive positive-sequence reactance.
I was doing fine until I got to the sequence part.
Any help would be appreciated.
thanks
Tom


Thomas-F