2020.05 / f
14
Electric Power Generation
Installation and maintenance
LSA R/H 49.1
Low Voltage Alternator - 4 pole
4528 en -
Cleaning of the stator, rotor, exciter and
diode bridge
The insulating components and the
impregnation system are not at risk of
damage from solvents (see the above list of
authorised products).
Avoid letting the cleaning product run into
the slots. Apply the product with a brush,
sponging frequently to avoid accumulation
in the housing. Dry the winding with a dry
cloth. Let any traces evaporate before rea-
ssembling the machine.
• Mechanical servicing
Cleaning the machine using water or a
high-pressure washer is strictly prohi-
bited. Any problems arising from such
treatment are not covered by our
warranty.
The machine should be cleaned with a
degreasing agent, applied using a brush.
Check that the degreasing agent will not
affect the paint. Compressed air should
used to remove any dust.
After cleaning the alternator, it is essential to
check the winding
insulation (see sections § 3.2 and § 4.8).
4.6 - Fault detection
If, when commissioned, the alternator does
not work normally, the source of the
malfunction must be identified. To do this,
check that :
- the protective devices are fitted correctly,
- the connections comply with diagrams in
the manuals supplied with the machine,
- the speed of the unit is correct (see
nameplate).
Repeat the operations defined in section 3.
WARNING
4.7 - Mechanical defects
Fault
Action
Bearing
Excessive overheating of one or
both bearings
(bearing temperature 80°C above
the ambient temperature)
- If the bearing has turned blue or if the grease has turned
black, change the bearing
- Bearing not fully locked (abnormal play in the bearing cage)
- End shields incorrectly aligned
Abnormal
temperature
Excessive overheating of
alternator frame (more than
40° C above the ambient
temperature)
- Air flow (inlet-outlet) partially clogged or hot air is being
recycled from the alternator or engine
- Alternator operating at too high a voltage (>105% of Un on
load)
- Alternator overloaded
Vibrations
Too much vibration
- Misalignment (coupling)
- Defective mounting or play in coupling
- Rotor balancing fault (Engine - Alternator)
Excessive vibration and humming
noise coming from the machine
- Phase imbalance
- Stator short-circuit
Abnormal
noise
Alternator damaged by a
significant impact, followed by
humming and vibration
- System short-circuit
- Misparalleling
Possible consequences
- Broken or damaged coupling
- Broken or bent shaft end
- Shifting and short-circuit of main field
- Fan fractured or coming loose on shaft
- Irreparable damage to rotating diodes/AVR, surge suppressor
