Hello Friends,
A practical experiment class conducted in my school
The title of the practical experiment
Is the strip down of three phase A.C induction motor for maintenance
The practical experiment was carried out by our lecturer where by he bring out all
the apparatus/tools use for the experiment which includes.
The photos of how the practical experiment was carried out
- Set of screw driver
2.Set of pliers,
3.Set of spanners
4.Mallet
5.Hammer
6.Allen keys
7.Pulley/puller
8.Marker
9.Megger tester,
The second photo of the practical experiment
Procedure.
The end covers of the induction motor were marked or number with chalk or crayon.
He said that the key on the shaft should be removed.
With the aids of screw drivers and scanner , the nuts of the cove were loosened,after which a Mallet is used to removed the casted framework of the machine by tender hitting.
The rotor of the three phase inductor machine was pulled out.
Third photo of the class
The motor terminal was opened and the type of connection (either in star or delta connection) was noted.
Also by the use of meggar instrument, the phase of the machine was identified.
The following test was carried out also
Phase to phase test
Phase to body/ casing.
Also the casing is tested to the phase which result to either open circuit or short circuit of the windings or cool.
Finally, observation and results was noted we were able to know the function of the motor starters which is
It protect motor and other connection equipment from sustained over load.
It permit automatic control when required.
It also limit inrush current where necessary.
It start and stop the motor.
He also teach us the maintenance of a c induction motor which he said that before putting the motor into service,you need to measure the insulation resistance between the motor winding and frame with merger or similar instrument and if it is below one meghom , as may be the case if the motor has been stored in a damp situation for some time,keep the motor in a warm dry place until the insulation resistance has risen at least this figure.
Conclusion
Special precautions was taken when the machine is idle for consideration period to avoid corrosion of the bearing and loss of grease
Thanks for going through my work