Installation and Maintenance Manual

GEI-M1031-B
18
V. MAINTENANCE (cont’d)
D. Anti-Friction Bearing Maintenance (cont’d)
2. Reassembly (cont’d)
VI. OPERATIONAL DIFFICULTIES
Some operating difficulties may occur, and their causes are given in the following chart and
should be corrected as soon as possible.
TROUBLE SHOOTING CHART
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
 Rough journal
 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
Insulation
Low Insulation Resistance or
Insulation Failure
 Moisture, dirt, metal particles, oil, or other
contaminants on the insulated windings
 Wrong voltage
 Excessive temperature
 Voltage surges
 Mechanical damage
 Excessive vibration with resultant mechanical damage
Table 7: Motor Endplay Ranges
Frame Size
Shaft Endplay (Inches)
Minimum
Maximum
140/180
0.020
0.045
210/250
0.031
0.057
280
0.039
0.065
320
None (Locked Bearings)