DC Motor and Drive
DC Motor and Drive
(OP)
Hi All,
I have a two DC motor application; the motors are mechanically coupled. They are driven by 2 DC drives; one each. One of the motors has had its armature rewound. Now when I run this motor up with the DC drive I get to around 50% load and begin to hear loud humming...it doesn't trip as yet...just the humming sound becomes more apparent. Running no-load seemed fine.
Question: what is causing this humming?
I have asked the plant to re-autotune the DC drive of the "humming" motor as obviously I suspect the resistance and inductance to have changed. I have asked them to also check the mounting of the encoder and ensure it is ok.
I have asked them to run the motors singularly. That is motor A/drive A measuring the speed/voltage/currents field/armature) etc....
then run motor B/drive B doing/measuring the same and see if the resultant data obtained are very similar.
Anything else I could suggest?
Regards
I have a two DC motor application; the motors are mechanically coupled. They are driven by 2 DC drives; one each. One of the motors has had its armature rewound. Now when I run this motor up with the DC drive I get to around 50% load and begin to hear loud humming...it doesn't trip as yet...just the humming sound becomes more apparent. Running no-load seemed fine.
Question: what is causing this humming?
I have asked the plant to re-autotune the DC drive of the "humming" motor as obviously I suspect the resistance and inductance to have changed. I have asked them to also check the mounting of the encoder and ensure it is ok.
I have asked them to run the motors singularly. That is motor A/drive A measuring the speed/voltage/currents field/armature) etc....
then run motor B/drive B doing/measuring the same and see if the resultant data obtained are very similar.
Anything else I could suggest?
Regards





RE: DC Motor and Drive
Make sure that windings have the right polarity (commutation windings or compensation windings are sometimes a problem). DC drives are not very common these days, so you may have a problem finding someone that can make it OK again.
The best strategy is to decouple both motors and run them under identical conditions. They then should behave almost identically. So your approach is right. I have done the same thing using a car battery. That sometimes makes any difference more pronounced and also makes measurements less dangerous.
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.
RE: DC Motor and Drive
RE: DC Motor and Drive