RETURNED GOODS
Contact Marathon Electric Manufacturing Corporation for
authorization before returning any product. We can not be
responsible for any items returned without authorization.
Single bearing generators must have their rotor
assembly properly secured to prevent damage during
transit to the factory, or to an authorized service cen-
ter.
TROUBLESHOOTING
This section is intended to suggest a systematic approach to
locating and correcting generator malfunctions. The section is
arranged according to the symptoms of the problem. The
steps have been arranged in an attempt to do the easy
checks first and prevent further damage when
troubleshooting a disabled machine.
The first step of troubleshooting is to gather as much
information as is possible from operating personnel and
individuals present during the failure. Typical information
includes: how long the unit had been operating; what loads
were on line; weather conditions; protective equipment that
did or did not function. In addition, information as to the
operating condition of the generator's prime mover is vital.
Has the prime mover been maintaining constant speed? If
not, have there been extended periods of under speed
operation? Has the prime mover experienced an over-speed
condition? If yes, what was the maximum speed, and how
long did the unit operate at that elevated speed?
The generator speed should be maintained at rated
nameplate value during all operating tests. The frequency of
the generator depends upon rotational speed. Most
regulators used with MagnaPLUS
®
generators have built in
under frequency protection such that if the speed is reduced
more than 5%, the voltage will drop off rather rapidly with
further reductions in speed.
15
430 FRAME 280 / 360 FRAME
A - Exciter Rotor Lead, B - Main Rotor Lead, C - Red (+) Suppressor Lead, D - Black (-) Suppressor Lead
FIGURE 5: ROTATING RECTIFIER ASSEMBLY
