G80XW/XF, G115XW/XF, G150XW/XF, G200XW/XF - 50HZ
OPERATION & MAINTENANCE MANUAL
116
G100XW/XF, G135 XW/XF, G170XW/XF, G225XW/XF - 60Hz
BEARINGS
MECHANICAL DEFECTS
The bearings are permanently greased Approximate life of the grease (depending on use) = 20,000 hours or 3 years.
FAULT
ACTION
Bearing
Excessive temperature rise
in one or both bearings
(bearing temperature more
than 80 °C) (With or
without abnormal bearing
noise)
- 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 temperature rise
in the alternator housing
(more than 40°C above the
ambient temperature)
- Air flow (intake-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
Vibration
Excessive 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
- Mis-paralleling
Possible consequences:
- Broken or damaged coupling
- Broken or bent shaft extension
- Shifting and short-circuit of revolving field winding
- Fan fractured or coming loose on shaft
- Irreparable damage to rotating diodes/AVR, surge suppressor
