Electric Power Generation
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Installation and maintenance
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5
8
7
4
en - 2020.01 /
a
TALA40
Low Voltage Alternators - 4 pole
4.3 - Bearings
The bearings are permanently greased
4.4 - Mechanical defects
Fault
Approximate life of the grease (depending on use) = 20,000
hours or 3 years.
Action
Excessive overheating of one or - If the bearing has turned blue or if the grease has turned
Bearing
bath bearings
(bearing temperature 80
°
C above
black, chan�e the bearing.
- Bearing not ully locked (abnormal play in the bearing cage)
the ambient temperature)
- End shields incorrectly aligned
Excessive overheating of
-Air flow (inlet-outlet) partially clogged or hot air is being
Abnormal alternator frame (more than
recycled from the alternator or engine
tempe rature 40
°
C above the ambient
-Alternator operating at tao high a voltage (>105% of Un on
temperature)
load)
-Alternator overloaded
- Misalignment (coupling)
Tao much vibration
- Defective mounting or play in coupling
Vibrations
- Rotor balancing fault (Engine -Alternator)
Excessive vibration and humming - Phase imbalance
noise coming from the machine - Stator short-circuit
- System short-circuit
- Misparalleling
Abnormal Alternator damaged by a
Possible consequences
noise
significant impact, followed by
- Broken or damaged coupling
humming and vibration
- Broken or bent shaft end
- Shifting and short-circuit of main field
- Fan fractured or coming loose on shaft
- lrreparable damage ta rotating diodes/AVR, surge suppressor
LEROY-SOMER'"
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