alt.energy.homepower

On Sun, 02 Sep 2007 18:24:32 -0000, philkryder < @ > wrote:


>I love it!
>
>do simple mechanical governor units - like Generac 8000w - stay synced
>once this is done?

Yes, absolutely. The same forces which will wreck a generator connected out of phase
hold the rotors in-phase. If one generator tries to "run" significantly faster than
the other then reactive current will circulate between them but that is of little
consequence as long as the total current remains below specification.

In the limiting case of one engine being turned off and assuming the field excitation
on the turned-off generator remains active, the generator on that unit will act as a
synchronous motor, spinning the engine at the same speed as the driving generator.
For fairly obvious reasons, this is undesirable so installations of parallel
generators that are un-manned normally include reverse power trip relays that open
the generator breakers when power flowing back toward the generator is detected.

Probably the worst problem to deal with when a generator gets overloaded sufficiently
to suffer field collapse. when this happens the units fall out of sync and any of a
number of unpleasant things can happen. The least unpleasant is that the generator
breaker will trip. Blue smoke leakage can be the worst result.

>
>What do you use to "trim the phase" on such a unit?

I don't recognize that term in this context. Do you mean how do I trim the speed
when syncing? Hand manipulation of the governor. Not hard to do with a little
practice.
--
John De Armond
See my website for my current email address

<-- best little blog on the net!
Tellico Plains, Occupied TN
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