On Sun, 27 Jul 2014 16:44:52 -0400, "Ralph Mowery"
wrote:


wrote in message
.. .
These "motor geerator sets" were "ward leonard" drives - AC motor
running DC generator to run variable speed DC motors bu varying the
field current of the DC generator. Parallelling DC generators is not a
serious problem Parralleling AC generators is a lot of fun, unless one
of them is a synchronous generator (like an overdriven induction
motor)

The MG sets we were using were 3 phase 480 volt systems. We often used the
light bulb or voltmeter system to put them in parallel. When the bulbs went
out or the volt metes went to 0, then the switch was flipped. They then
drove a bank of about 16 motors that were around 3 or 5 HP at 480 volt, 3
phase.

OK, so basically mechanical phase converters?
The input was single phase AC? How did you vary the speed of the prime
mover?Mechanical variable speed drive?