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(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.
VI.
OPERATIONAL DIFFICULTIES
Some operating difficulties may occur. Common causes are given in Table 2 and should be corrected as soon as
possible.
Affected Parts
Windings
Bearings
Motor
Winding Insulation
*
Sleeve bearings
**
Anti-friction bearings
TROUBLE SHOOTING CHART
Difficulty
Overheating
Overheating
Excessive Vibration
Low insulation resistance
or insulation failure
bearing should be coated with a sealing compound
such as No. 3 Permatex.
the disassembly procedure.
Table 2
What to Check
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
•
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 **
•
Unbalance
•
Misalignment
•
Improper or settled foundation
•
Non-uniform air gap
•
Rubbing parts
•
Bent shaft
•
Unbalanced stator current
•
Damaged bearing
•
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
•
13
GEI-56128H
(4) The sealing surfaces of the
(5) To replace the bearing, reverse
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