commutator stuffed

[Slim shady]

hi all
i have a 4 pole brush dc motor running off a vsd which seems to burn up the commutator only on two of the poles\Brushes.
i've replaced the motor with a recondition com and i still have the prob.

i believe the prob is with the speed drive maybe a setting i can get more information for anyone willing to help.

thanks
slim

 

[Slim shady]

reply

reply

i'm hoping someone can direct me to another site that can help ???

 

[Besoeker]

hi all
i have a 4 pole brush dc motor running off a vsd which seems to burn up the commutator only on two of the poles\Brushes.
i've replaced the motor with a recondition com and i still have the prob.

i believe the prob is with the speed drive maybe a setting i can get more information for anyone willing to help.

thanks
slim

Did you replace the whole motor or just the commutator? Or the armature.
If so, it could be a problem with the interpoles (mounted in the stationary part of the motor) in which case they may need a rewind or replace the whole motor.

If the same problem has occurred on two different motors it could be a problem with the drive power circuit or the application.
I came across a similar sort of problem a few years ago. The motor had been designed to run on smooth DC from a DC generator. The generator had been replaced by a six-pulse DC drive. The current ripple or, more precisely, the rate of change was greater than the motor was designed to take.
My solution in that instance was to fit chokes in the DC output from the drive to smooth the current.
Don't know if the helps or confuses.
:-?

 

[Slim shady]

thanks

thanks

yeah different motor all togethor but same model-make. it confuses me why its only on two poles not all 4. but i agree that the drive output is to harsh for the com.

maybe a talk with the drive manufacture will be able to shine light on it.

 

[eric9822]

If its only on two poles you may want to confirm you have the correct spring tension and that the brush holders are aligned correctly.

 

[Slim shady]

it was a completly replaced motor i shouldnt have the same two brushes burning out on the changed motor aswell. the wear on those two brushes are of a damaged edge and a rough surface the other edge of the brush is that of a normal brush edge..

how can i determine the size of choke that i may need for a smoother wave.??