snip

I was told that when the wire coming from the control module was cut
by vibration due to improper routing, that the generator continued to
spin for some time and caused the magnetic field of the generator to
become confused.

The shop followed Generac's instructions and hooked up a DC power
supply to the slip rings of the generator and realigned the magnetic
field. After doing so, it works fine.

Has anyone ever heard of this?

If not, I'm going to call Generac myself and have them explain how and
why this happened.

I'm not sure I believe this explanation that cost me $275.00

If someone HAS heard of this or at least understands how this really
works, please tell me.

Thank you.


Generators of this type are self-exciting. This means some of the
output of the generator is rectified (converted to DC) and used to
provide the magnetic field that the generator uses to generate
electricity.

This leads to a chicken and egg situation. The generator must be
generating power to provide the magnetic field it needs to generate
power.

The reason this works is due to some residual magnetic field that
remains in the iron when the generator is off. This is enough to get
things going when you start the generator. But...there are a few
things than can cause problems. One is time. If the generator is not
run for a long time, the residual field can decay to the point where
you will get no power output when you start it. Most manufacturers
recommend running the generator for a short while every few weeks.
That will prevent this.

Now, your generator probably uses a brushless alternator, which
complicates the situation somewhat, but the basic principle still
applies. You need a little residual magnetism, in the right places
and with the right orientation, to get things going. I can believe a
problem with the control board, which would be handling commutation of
the brushless alternator, Could mess this up.

So the story you got is at least feasible....

HTH,

Paul