Bob Engelhardt wrote:

jk wrote:

I wrote:
... generator breaker would blow in about a millisecond.

Probably significantly longer, especially if your voltage regulator
isn't very stiff. Essentially you voltage doesn't rise, and your gen
set acts much more like a constant current generator rather than
constant voltage. ...

That sounds like what would happen if the generator were started under
load. Is that what you're suggesting? If so, do people really do
that? I always start my generator without load and switch on the load
after it's up to speed.

Otherwise, switching the load on after the generator is running would
surely pop the breaker. That's what breakers are for. You're not
saying that you can dump a dead short across a generator and have it act
like a "current generator" with a lowered voltage?

In some cases, yes that is exactly what will happen. A bus fed
excitation system isn't all that capable of exiting the field when it
sees well below rated voltage at it's output. It is much less likely
when you just dump the dead short on the generator that is already up
at it's output, due to exciter time constants, and the fact that you
have already built up the rotor field.

In fact doing this in a controlled fashion, is one way you can test
generator outputs at full current with out an external high current
source.
jk