[Milsurplus] Aircraft Electrical Question

[Mike Morrow]

>I'm no expert but I thought it all comes from 3 phase Wye grounded neutral.

A grounded neutral would be one way of assuring that AC power will *fail* upon
the occurance of a single phase-to-ground fault anywhere.  Neutral-grounded wye
would be a very poor indicator for AC reliability in a critical application.

Even large electric utility generating stations do not use a grounded-neutral
on the wye-connected main generator, which feeds a delta-connected primary on
the transformer bank that connects to the switchyard.  Generator neutral-to-
ground overvoltage is used to indicate a ground fault in such systems, which
trips the generator electrically before any real adverse fault current can
develope.

Mike / KK5F