'Flash' the fields of a generator

In a discussion of the operation of a static voltage regulator, the following observation appeared:
"It is always proper to flash the fields of the auxiliary generator when the generator, voltage regulator, or auxiliary generator is removed and replaced with new or properly repaired equipment."
What is meant by 'to flash the fields'?

I THINK it has to do with setting the polarity, I can remember my father telling me something of the sort on old cars. They needed to be hooked up to a battery before spinning to set the polarity, I think.

A generator has both a positive and negative pole that don't change where an alternator will reverse poles every 1/2 or 1/3 revolution, a diode and capacitors make the power flow in only one direction

That sounds about right. Going back a few years ago, I remember one of my bosses, an electrical engineer, talking about an assignment he had as a service engineer for Brown-Bovari. He put a large DC genset into commission on a supertanker, and to set up the polarity correctly, he borrowed the battery from his rental car-

Yup - I found it in Wiki:

http://en.wikipedia.org/wiki/Excitation_%28magnetic%29

Thanks for your help, guys.

Print 1919 American Technical Society - This may by due to (a) vibration or jar; (b) proximity of another generator; (c) earth's magnetism; (d) accidental reversed current through field, enough to completely reverse magnetism. The complete reversal of the residual magnetism in any machine will not prevent its generaring, but will only it build up of opposite polarity. Sometimes reversal of residual magnetism may be very objectionable, as in case charging storage batteries, but, although the popular supposition is to the contrary, it will not cause the machine to fail to generate.
Symptom. Little or no magnetic attraction when the pole piece are tested with a piece of iron.
Remedy. Send a magnetizing current from another machine or battery the FIELD COIL (ONLY), then start and try the machine ; if this fails, apply the current in the opposite direction, since the magnets may have enough polarity to prevent the battery building them up in the direction first tried.


Smile

Stan Paulsen