MarelliMotori M31FA600A M EC-20 Manual De Instrucciones página 34

In the event of one of the problems described below, conduct the proper troubleshooting/problem
determination by disconnecting any other devices connected to the voltage regulator (power factor
regulator, overexcitation device, external remote controls, etc.).
In the event that the problem does not occur when only the voltage regulator is operating, reconnect
the auxiliary devices one at a time to identify which one causes the problem. Then consult the User
Manual related to the identified device.
If the available documentation is not sufficient for solving the problem, contact Marelli Motori
Services for further instructions.
All operations indicated below are to be performed with the machine off, except where specifically
noted.
PROBLEM
With the generator
started, with no-load, the
voltage to the output
terminals is less than the
nominal value and equal
to the residual voltage of
the machine; this value
remains even after
having adjusted the
VOLT and VFINE
potentiometers.
Once the blown fuse is
replaced, there is again
a fuse interruption.
963857154_H
POSSIBLE CAUSE
There is no connection between
regulator power terminals P1 and P2
and (according to the application):
 the auxiliary winding
 the main generator output
terminals
 the PMG output
There is no connections between the +
and - terminals on the regulator and
the exciter field.
Terminals P and Q have no jumper or
are not connected to an external
potentiometer.
Regulator powered
winding: the residual voltage of the
auxiliary is insufficient
excitation (minimum voltage required,
5V).
Regulator powered
terminals: the residual
voltage between P1
insufficient for
(minimum voltage required, 5V).
Regulator powered from the PMG: the
PMG output voltage and P1 and P2
input voltage is insufficient for self-
excitation (minimum voltage required,
5V).
Internal fuse interrupted
Regulator failure.
Regulator failure.
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OPERATION
Check connections (ref. connection
diagram provided with the generator).
Check connections (ref. connection
diagram provided with the generator).
Check connections (ref. connection
diagram provided with the generator).
by auxiliary Bring the generator to nominal speed
and measure the voltage output from
for self- the auxiliary winding.
If this is less than 5V, increase the
residual magnetism of the generator
following
generator
Manual.
from main Bring the generator to nominal speed
generator and measure the voltage between P1
and P2 is and P2.
self-excitation If this is less than 5V, increase the
residual magnetism of the generator
following
generator
Manual.
Bring the generator to nominal speed
and measure the voltage PMG output
voltage. If it is less than 100V, contact
Marelli Motori Services for further
instructions.
Replace the fuse.
Replace the regulator.
Replace the regulator.
M31FA600A MEC-20
the instructions in the
Use and Maintenance
the instructions in the
Use and Maintenance
33