8
TROUBLESHOOTING
Below are listed some abnormal situations that can occur on the switch in service, as well as the correct procedure for
verification and correction.
ANOMALY
Interruption in the auxiliary winding circuit.
Burned fuse.
Residual voltage too low.
Drive speed is not correct.
Interruption in the main excitation circuit.
Relay or other component of the voltage regulator
faulty.
External potentiometer for voltage adjustment
ruptured or interrupted connection.
Varistor of protection of the diodes (if any) is faulty.
ANOMALY
Faulty rotating diodes.
Incorrect speed.
Voltage adjustment below the rated voltage.
Supply of voltage regulator is not according to the
desired output voltage.
IN NO LOAD, THE ALTERNATOR EXCITES UP TO RATED VOLTAGE, BUT COLLAPSES WITH THE LOAD
ANOMALY
Sharp speed decrease.
Faulty rotating diodes.
10680382
Installation, operation and maintenance manual – Synchronous Alternator – G line - Horizontal
THE ALTERNATOR DOES NOT EXCITE
ALTERNATOR DOES NOT EXCITE, UP TO RATED VOLTAGE
PROCEDURE
Check the union of the cables of the auxiliary winding in the
connection block extending to the connecting block the regulator and
fuse.
Replace the fuse (as specified).
Disconnect the wires to the regulator and perform external excitation
with battery 12 to 20Vcc (negative pole in F- and positive pole in F +),
until the beginning of the excitation process. The starting battery of
the diesel engine should not be grounded.
Measure the speed and regulate it
Check the continuity of the cables F- and F +, make measurements
in all the diodes and replace defective diodes or replace the whole
set.
Replace voltage regulator.
Check the connections to terminals 11-12 and potentiometer.
If defective, the varistor should be replaced, or there is no a spare
part, remove it temporarily.
PROCEDURE
Replace the set of diodes.
Measure the speed of the primary machine and regulate it.
Adjust the voltage potentiometer in the voltage regulator or the external
one.
Verify if connections are according to the manual of voltage regulator.
PROCEDURE
Control Diesel selector.
Replace the set of diodes.
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