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Start by
Hatem Kashap
10-02-2013 09:33 PM

Effects of an Unstable load on motor

We have a cylinder used for granulation,this cylinder is driven by motor 90 Kw via a gearbox,
there is a mechanical problem that result in a fluctuation in motor current from 70 A to 130A ,
i ask if this fluctuation has a negative effect on motor.
10-03-2013 12:06 AM
Top #2
Ing. Ole Knudsen
10-03-2013 12:06 AM
You should compare the motor current with the nominal current stated on the motor nameplate. Assuming that the motor is designed for 400V, it does not seem to be excessively loaded, so provided the current fluctuations is not accompanied with excessive vibrations, it may not be a big problem in itself. If you over time experience undue wear of the motor, you can replace it with a heavy-duty version eventually.
10-03-2013 02:08 AM
Top #3
Yudhi Susetyo
10-03-2013 02:08 AM
If the name plate of the motor nominal current is exceeded then I replied Yes. First step for more details can be measured without load, and then compare it with the use of load. Regards.
10-03-2013 04:09 AM
Top #4
Raymond Lee
10-03-2013 04:09 AM
As long as the phase current is balanced and the 130A is less than or equal to the rating of the motor, you should have nothing to worry about.
10-03-2013 06:59 AM
Top #5
Lester Philip Lualhati
10-03-2013 06:59 AM
your motor winding insulation may deteriorate slowly, if you exceed much from the nameplate current ratings... you must address the root cause of the motor current fluctuation since the amplitude of current rise may be worsen as the motor service run progresses...
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