Nanni Q1100 Series, User Manual

Page: 84 / 98

84
S08 ALTERNATOR
MAINTENANCE
The NPE series alternators are designed to provide a long
maintenance-free life.
CAUTION!
Before performing this operation, read the safety
requirements at the beginning of this section.
Maintenance operations on generators can be divided
into ordinary and extraordinary maintenance operations;
in both cases, all operations must be authorized by
the safety representative and they must be carried out
when the machine is switched off and isolated from the
electrical system or from the electrical network.
Maintenance operations and any troubleshooting must
be carried out by highly qualified mechanical or electrical
technicians, as all the operations described below can put
personnel at serious risk.
It is also strongly recommended that all necessary
precautions be taken to avoid accidental start-up of
the machine during maintenance and troubleshooting
operations.
The routine maintenance operations can be summarized
as follows:
1. Evaluation of the condition of the windings after long
periods of storage or inactivity
2. Regular evaluation of the correct operation (absence
of abnormal noises or vibrations).
3. Mechanical checks of all fastening bolts and, in
particular, of the electrical connections.
4. External cleaning of the generator
The extraordinary maintenance operations can be
summarized as follows:
1. Maintenance and replacement (if necessary) of
bearings
2. Cleaning of the windings
3. Replacement of the diode bridge
4. Replacement of the exciter
5. Replacement of the voltage regulator
6. Checking the residual voltage
ROUTINE MAINTENANCE
Evaluation of the condition of the windings after long
periods of storage or inactivity.
Intervention type Operator
PPE to wear Periodicity
Every 2500 hours of use
Materials and equipment
Megohm-meter or similar up to 500V DC.
DANGER!
Disconnect the alternator from its power supplies. The
drive motor must be stopped and disconnected from its
power supplies.
The measurement of the resistance of the insulating earth
allows to evaluate the state of the windings.
This measurement can be made with a Megohmmeter or
similar device, with a DC voltage of 500V.
NOTE!
It is very important to disconnect the voltage regulator
(fig. a), the rotating diode bridge (fig. b) and the radio
interference filter (fig. c), as well as any other device
connected to the windings to be tested, before making
the measurement.
fig a