Motor

[gobir12]

Hi,

I have a d.c compound motor,110v,25A draws a steady high current of 100A,when connected to the supply.What are the possible causes and remedy.

Thanks

Gobir

 

[Skogsgurra]

Loss of excitation? I presume there's a mechanical load. Otherwise a coumpound motor is known to self-destroy at high speed.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[ScottyUK]

No shunt field is a great way of doing this. A more remote possibility is a reversed shunt field being almost perfectly cancelled by the series field carrying stall current leaving virtually no net field.

Remedy is check the shunt field is a) carrying current b) of the correct polarity.


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Sometimes I only open my mouth to swap feet...

 

[aolalde]

The series field ampere turns must add to the shunt field ampere turns. If the polarities are different one field tries to cancel the other, then the total magnetic flux is reduced and the armature counter electromotive force is low.
Since the armature and series field resistances are low the armature current increases. See diagram below.
Check that you have current into this shunt field. If you check current is OK, then reverse F1 and F2 connections to make your field cummulative.

 

[waross]

Is it drawing 100 amps loaded or unloaded?
What is the load?
respectfully