In article ,
F. George McDuffee wrote:

On Sun, 22 Feb 2009 13:05:30 -0500, Joseph Gwinn
wrote:

I went quiet while I researched the issue of how RPCs work and if a RPC
supplies some of its own kinetic energy to the three phase motors
connected to it. (It does.)

The purpose of this posting is to report my findings, and is a
continuation of the February 2009 thread "VFD as 3Ph shop supply".
snip
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Thanks for getting back to the group and letting us know what you
discovered. Nice report.

Thanks. It's certainly an issue of wide interest in RCM.

One thing. I think I recall some debate and difficulty on starting
RPCs, given that most three phase motors lack centrifugal switches to
disconnect the start capacitor. I came upon a solution in my research.
In the report and patents, a simple approach is given: Use a voltage
relay to measure the voltage of the generated phase, the relay in turn
controlling a contactor that disconnects the start capacitor when at
least 80% of normal speed is achieved. This approach was praised in the
report for its simplicity and reliability, and appears in both relay and
its solid-state equivalent in more modern patents.

Joe Gwinn