If the voltage is set any higher than its maximum limit
the generator may be damaged.
CAUTION!
Further adjustments are possible with the AVR TERM
software.
6.4.5 Wiring diagrams for different circuits
In the appendix of this manual there are diagrams for
connections other than the factory star-series connec-
tion (standard unless otherwise specified on order).
6.4.6 Initial start-up
Before starting up the generating set check that all ex-
ternal connections are in order and that the protections
are in place.
During the initial start-up pay particular attention for any
unusual noise that might signal an incorrect alignment
between engine and generator.
Do not touch the generator while in operation and
immediatly after the generating set has stopped,
since certain parts may still be very hot.
WARNING!
Generators are rotating electrical machines that involve
potentially hazardous live or moving parts, therefore the
following is strictly prohibited:
• an improper use;
• removal of covers and disconnection of safeties.
Due to these inherent hazards, all works of electrical
or mechanical nature must be carried out by qualified
specialists.
The lack of routine check-ups and poor maintenance
can cause severe damage to persons and/or
objects.
WARNING!
7. AFTERSALES ASSISTANCE AND
MAINTENANCE
The maintenance and fault diagnostic procedures
involve risks that may cause severe injury or
even death. These procedures should therefore
WARNING!
be carried out solely by qualified electrical and
mechanical specialists. Before any maintenance
and cleaning work make sure that there are no
live parts, that the generator housing has cooled to
ambient temperature, that the generating set cannot
be accidentally started up and that all procedures
are strictly observed.
7.1 Control and check procedures
7.1.1 Control of windings and electrical insulation
The condition of the windings can be checked by
measuring their electrical resistance to earth. While
running this test disconnect the voltage regulator and
EMC filter. It is usually sufficient to control the main
winding.
The readings should give a measurement of at least
2MOhm. If the insulation resistance is below this
threshold, the alternator alone should be oven dried
at 80 ÷ 100°C for 6 hours. Before carrying out this
operation remove the voltage regulator.
7.1.2 Control of the rotating rectifier diodes
This check can be performed with a multimeter, the
knob must be selected to the position "Diode test".
The lead of each diode (1) has to be removed from the
connections with the rotor exciter (see figure), but it's
not necessary to removed them from the alluminium
plate (2) where they are fixed.
The faulty diode will have high (theoretically infinite)
resistance in both directions (open diode) or it can
have low resistance on both directions (diode in short)
by placing the tips on both directions. Meanwhile
the correct working diode will have low resistance in
forward direction and high (theoretically infinite) in the
other (reverse) direction.
7.1.3 Control of the surge suppressor
This element (surge suppressor 3, see above figure),
that is connected between two terminals of rectifier
bridge, is meant to suppress high voltage peaks on
the main rotor winding and save rectifiers diodes from
damaging. Normally, if good, this element will have high
(infinite) resistance in both directions. When damaged,
in most cases it can be noticed by visual inspection.
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