9
2020.01 / b
Electric Power Generation
Installation and maintenance
LSA PMR 320
Alternator for rail application - 8-pole
5785 en -
4.3 - Bearings
The bearings are regreasable
Life of the grease = 700 hours or 1 year
Grease: Mobil Polyrex EM NLGI2
Amount of grease at each regreasing = 51 g minimum
4.4 - Mechanical defects
Fault
Action
Bearing
Excessive overheating of one or
both bearings
(temperature above 125°C)
- 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 PT 1000 sensors (more
than 190°C)
- Alternator overloaded
Vibrations
Too much vibration
- Misalignment (coupling)
- Defective mounting or play in coupling
- Rotor balancing fault
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
Possible consequences
- Broken or damaged coupling
- Broken or bent shaft end
- Rotor magnets are demagnetised
4.5 - Electrical faults
Fault
Action
Effect
Check/Cause
No voltage
at no load on
start-up
Check the connections in the
terminal box
-
-
Voltage too low
Check the drive speed
Correct speed
Magnets demagnetised following a stator
short-circuit
Speed too low
Increase the drive speed
Voltage
oscillations
Check the stability of the
motor speed
-
-
Voltage
disappears
during operation
Check the connections in the
terminal box
-
-
• Checking the winding
You can check the winding insulation by performing a high voltage test.
