# Voltage effects on DC motors



## major (Apr 4, 2008)

Element One Dan said:


> Suppose I have a 200V battery system and an 84V motor. If the PWM is set to 42% (or 84V average), will the 200V spikes (although happening very fast) have any long term effects on the motor?


That should not be a problem.


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## Tesseract (Sep 27, 2008)

I can add my observations to that as well... When dyno testing the Soliton1 controller we did not see any change in sparking across the brushes whether using a 120V, 192V or 288V pack - only when the _power_ applied to the motor reached a certain level did sparking get bad (in other words, as long as the voltage pulses are't high enough to break down the insulation or ionize the air, the motors don't really seem to care.

CAVEAT - PWM'ed high voltage does seem to have some effect on the shaft bearings, but I have only seen this reported happening on 3ph. ac motors. However, it should be equally likely to occur on DC motors.


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