10
2020.05 / c
Electric Power Generation
Installation and maintenance
LSAH 44.3
Low Voltage Alternator - 4 pole
5577 en -
4.3 - Bearings
The bearings are greasable
- Life of the grease = 4,000 hours or 3 years
with «NLGI Lithium» grease - Level 3 or equivalent
(viscosity 40°C -> 115 mm²/s & 100°C -> 10mm²/s)
- Grease quantity: - RLT 6308 = 10 gr
- RLT 6314 = 26 gr
4.4 - Cooling circuit
Composition
Water, anticorrosion oxygen inhibitor, glycol-type antifreeze up
to 50%
Maintenance
Coolant change interval = 16,000 hours or 2 years the first of
two who is reached
4.5 - 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)
- 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
