Page 375 - Electrician 1st year - TT - Malayalam

Table 1

Sl.No. Complaints Causes Test and remedy
1 Motor does not start Short-circuited windings. Rewind the windings.
Grounded winding. Rectify or rewind the windings.
Open circuited windings. Solder the joints; if not possible rewind the windings.
Broken wire from line cord Solder the broken wire in the line cord or change the
to windings. line cord.
Defective capacitor. Replace the correct capacitor.
Blown fuse. Find the cause and replace the fuse.
Excessive load. Reduce the load.
Defective centrifugal switch. Rectify or replace the defective switch.

2 Motor starts but heats Centrifugal switch not Rectify or replace the centrifugal switch.
up rapidly opening.
Short-circuited winding. Rewind the windings.
Grounded winding. Rectify or rewind the windings.

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

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

5 Motor runs intermittently Intermittently open line Repair or replace the line cord.
cord.
6 Motor is noisy Worn out bearings. Clean and lubricate or replace the bearings.
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 switch. Replace centrifugal switch.
Rotor rubs stator. Find the cause and rectify.
7 The user gets a shock Contact between live parts Rectify isolation between body and the live parts of
and body of the motor. the motor.
Broken ground strap. Replace ground strap.
Poor ground connection. Inspect and repair ground connection.
8 Motor fuse blows Grounded or short-circuited Rectify or rewind the windings.
windings.
Low capacity of fuses Replace with proper capacity of fuses.
Grounded near the switch Repair or rewind the winding.
end of the winding.

ഇലക്്ടട്്രരീഷ്്യൻ (NSQF - പുതുക്തിയ 2022) േതി. സതി . റവണ്തി എക്്ടസതിർസസസ്ട 1.11.96
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