Installation and Maintenance Manual

GEI-56128H
13
(2) Inspect the journals and polish
them with crocus clothe if any scratches are detected.
Do not allow any metal dust to fall into the housing
when polishing the journals.
(3) Spread a thin coat of oil over
the journal and bearing surfaces before reassembling.
(4) The sealing surfaces of the
bearing should be coated with a sealing compound
such as No. 3 Permatex.
(5) To replace the bearing, reverse
the disassembly procedure.
VI. OPERATIONAL DIFFICULTIES
Some operating difficulties may occur. Common causes are given in Table 2 and should be corrected as soon as
possible.
TROUBLE SHOOTING CHART
Table 2
Affected Parts Difficulty What to Check
Windings Overheating
• Calibration of measuring instrument
• Excessive Current
• Unbalanced AC current
• Improper or restricted ventilation
• Excessive ambient temperature
• Short circuited coil or windings
• Dirty windings
• Unbalanced voltage
Bearings Overheating
• Calibration of measuring instrument
• Worn out or dirty oil *
• Rough journal *
• Oil rings jammed *
• Insufficient Oil *
• Misalignment
• Excessive end thrust or radial loading
• Shaft currents
• Excessive or insufficient grease **
• Worn out or dirty grease **
Motor Excessive Vibration
• Unbalance
• Misalignment
• Improper or settled foundation
• Non-uniform air gap
• Rubbing parts
• Bent shaft
• Unbalanced stator current
• Damaged bearing
Winding Insulation Low insulation resistance
or insulation failure
• Moisture, dirt, metal particles, oil, or other contaminants on
the windings
• Wrong voltage
• Excessive temperature
• Voltage surges
• Mechanical damage
• Excessive vibration with resultant mechanical damage
* Sleeve bearings
** Anti-friction bearings