In my previous post,you have come to know about some faults,it's reason and rectification of electric motor.This post will gain your knowledge about

more faults occuring in Electric Motor due to which you can protect your Air Compressor unit from stopping to perform.I will try to cover more and more

faults so you can rectify it as early as possible and minimise your shutdown time of plant operations and Air Compressor.

Let's see some more faults,it's reason and rectification.

(E)FAULT:-MOTOR TAKES TOO LONG TO ACCELERATE.

Reason:-(01) Applied voltage is too low.

Rectification:-(01) Improve voltage upto requirment.

Reason:-(02) Excess loading.

Rectification:-(02) Reduce load on motor if it is overloaded.

Reason:-(03) Poor circuit.

Rectification:-(03) Check for high resistance.

Reason:-(04) Defective Squirrel/Cage rotor.

Rectification:-(04) Replace with new rotor.

(F)FAULT:-MOTOR OVERHEATS WHILE RUNNING UNDERLOAD.

Reason:-(01) Check load.

Rectification:-(01) Reduce if overloaded.

Reason:-(02) Wrong blowers and air shields may be clogged with dirt and prevent ventilation of motor.

Rectification:-(02) Good ventilation is mainfest when a contineous stream of air leaves the motor.

Reason:-(03) Motor may have one phase open.

Rectification:-(03) Check to make sure that all leads are well connected.

Reason:-(04) Grounded coil.

Rectification:-(04) Repair as early as possible.

Reason:-(05) Unbalnced terminal voltage.

Rectification:-(05) Check for faulty leads,connection and cables.

Reason:-(06) Faulty connection.

Rectification:-(06)Rectify connection.

Reason:-(07) Rotor rubs stator.

Rectification:-(07) If not poor machining,worn/defective bearings.

(G)FAULT:-WRONG ROTATION.

Reason:-(01) Wrong phase sequence.

Rectification:-(01) Reverse connection at motor terminals or switch board.

(H)FAULT:-MOTOR VIBRATES AFTER CONNECTIONS HAVE BEEN MADE.

Reason:-(01) Motor misalignment.

Rectification:-(01) Realign electric motor and air compressor.

Reason:-(02) Foundation nuts of electric motor or compressor may be loose.

Rectification:-(02) Tighten all the foundation bolts of motor and air compressor.

Reason:-(03) Wound rotor coil replaced.

Rectification:-(03) Rebalnce rotor.

Reason:-(04) Motor running for single phase.

Rectification:-(04) Check for open circuit.

Some more faults will be disclose in next post Part-C.

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