MarelliMotori MARK V Manuel Utilisateur page 29

If the voltage at the output terminals is equal to or less than 120% of the rated
voltage, go to Step 2.
Step 2 Check the calibration of the VOLT meter.
SPECIAL CASE: with external potentiometer connected to terminals P and Q, the
voltage internal reference shifts to higher values (up to a maximum of 20% more); in
this case you need to reset the VOLT meter.
Reset VOLT so as to bring the generator at rated voltage.
Otherwise, go to Step 3.
Step 3 Replace the voltage controller.
At nominal speed, with or without load, the voltage adjustment is inaccurate and / or unstable
(it is assumed that the prime mover is operating properly).
Step 1 Check the connections.
Change any incorrect connections.
Otherwise, go to Step 2.
Step 2 Check the correct setting of the stability of the control system.
Rotate STAB clockwise / counter-clockwise until reaching the required stability /
accuracy.
Otherwise, go to Step 3.
Step 3 Replace the controller.
8.3. AVR ANALYSIS
The following paragraph provides a procedure for the identification of the AVR failure and the
proper filling in of the annexed report form (APPENDIX).
All the checks and measurements specified herein must ALWAYS be performed with
the AVR disconnected from the alternator.
This document allows to identify the failures occurring in the AVR envelope, in the
main components and/or in the AVR power supply circuit.
The accuracy and steadiness of the regulation can only be verified in the final
application for which the alternator is used.
IMPORTANT: in case of malfunction or if any AVR failure is detected, for any AVR claim to be
accepted the user must have carried out the preliminary procedure described herein and filled in
the report form in its entirety.
In case you experience any of the difficulties listed in this chapter please follow the troubleshooting
and repair procedure described
963857121_M
Mark V M16FA655A
EN
Marelli Motori
29