Motor's "Nominal voltage" versus a Controller's "Supply voltage"?

Topic:

• Can a motor be operated with a higher controller's supply voltage than specified by the motor's "Nominal voltage"?
• Is there some risk that the motor winding gets damaged if a higher voltage than the specified motor's "Nominal voltage" is applied?

Solution:

The motor's "Nominal voltage" has no meaning about the voltage which can be applied to the motor winding or to the motor controller. 

Please find the meaning of the "Nominal voltage" by "Explanations of maxon terminology EC motor"  resp. "Explanation of maxon terminology DC motor" of maxon's catalog (-> http://epaper.maxongroup.com), e.g. by page 86, 90 or page 186 of maxon's catalog 2022/2023: 
​

General notes:

• The controller adapts the motor voltage according to the commanded speed and controls the motor current according to the demanded motor torque to follow a position or speed command resp. profile.
  A motor controller acts as a power converter, see also by this linked Support Center document:
  -> Motor controllers: Input current versus Motor current, Power Conversion
  
  
• A supply voltage of 24VDC or 48V or even 70VDC in case of higher rated ESCON or EPOS motor controllers will not harm or damage a motor specified for a lower "Nominal voltage" level. 
  
  
• It is recommended to select a controller with a power stage with a "Continuous output current" rating which fits roughly to the motor's "Nominal current".
  The supply voltage of the controller is less (or even not so) important. Just do not(!) select a strongly oversized power stage concerning the power stage's current rating compared to the motor's "Nominal current". Select the controller power stage which is closest above the motor's "Nominal current". 
  
  
• Take care that the supply voltage of the controller is sufficient to reach the commanded speed.
  Please find some more information about this by the following linked Support Center document:
  -> What supply voltage is required by a controller? 
  

  Finally this even means that the controller's supply voltage has to be higher than the specified motor's "Nominal voltage" if you want to reach the motor's "Nominal speed" (due to some motor data tolerance and voltage drop by the controller).

Conclusion:

A controller supply voltage of 24V or 48V are typically in use by most applications because this is the rating of most industrial power supplies too. Finally the controller's supply voltage has to be high enough to reach the required motor speed. It means no disadvantage or and there is no risk of a motor's winding damage as long as the controller's supply voltage is within its specified voltage range. 

Specific note concerning DC motor and direct supply:

A DC motor can be also operated by a supply voltage directly connected to the +/- cable of the motor (without any controller in between). In this case it has to be ensured that the supplied voltage does not result in a motor shaft speed (= approx. 'supply voltage' x 'speed constant) which exceeds the motor's "Max. speed" rating.

If the "Max. speed" is exceeded, the motor's life expectance can be strongly reduced or even damaged quite fast (e.g. by an internal bearing or winding damage).