Page 281 - Electrician - TT (Volume 2)

ELECTRICIAN - CITS

3 Motor runs too hot Short circuited windings. Rewind the windings.
Grounded winding.
Bearing too tight. Rectify or rewind the windings.
Short capacitor. Clean and relubricate the bearing.
Worn out bearings. Replace the capacitor.
Replace the capacitor.

4 Motor runs slow Insufficient lubrication Clean and re-lubricate the bearing.
or foul lubrication that
tends to bind the motor
shaft.

5 Motor runs Intermittently open line Repair or replace the line cord.
intermittently cord.

6 Repair or replace the Worn out bearings. Clean and lubricate or replace the bearings.
line cord. Excessive end play. If necessary, add additional end play washers.
Bent shaft. Straighten or replace the shaft.
Unbalanced rotor. Balance rotor.
Burrs on shaft. Remove burrs.
Loose parts. Tighten the parts.
Worn out belts. Replace the belts .
Misalignment. Align pulleys correctly.
Worn out centrifugal Replace centrifugal switch.
switch. Find the cause and rectify.
Rotor rubs stator.

7 The user gets a The user gets a shock Rectify isolation between body and the live
shock and body of the motor. parts of the motor.
Broken ground strap. Replace ground strap.
Broken ground strap. Inspect and repair ground connection.

8 Motor fuse blows Grounded or short- Rectify or rewind the windings.
circuited windings. Replace with proper capacity of fuses.
Low capacity of fuses Repair or rewind the winding.
Grounded near the
switch end of the
winding

9 Smoke from motor Overload. Reduce the load.
(motor burnt out)
Shorter windings. Rewind the windings.
Faulty centrifugal switch. Repair or replace the centrifugal switch.
Frozen bearing. Clean and lubricate or replace the bearing.
Short capacitor Replace the capacitor.
10 Rotor rubs stator Dirt in motor. Clean the motor.
Burrs on rotor or stator. Remove burrs.
Worn out bearings. Replace the bearing.
Worn out bearings. Straighten or replace the shaft.
11 Excessive bearing Belt too tight tension Correct the mechanical condition.
wear Dirty bearings Clean and lubricate or replace the bearing
Insufficient lubrication Lubricate with appropriate lubricant.
Thrust over load Reduce thrust load
Bent shaft Straighten or replace the shaft.

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CITS : Power - Electrician & Wireman - Lesson 101-103