Will under-voltage damage motor?

[Moola]

I have a 26v 20amp centrifical blower motor that I want to run using a 12v car battery. Will this under-rated power source damage the motor? Besides lower output, what affect might this have on the motor?

 

[waross]

I assume this is a DC motor. Speed control of DC motors by varying voltage has been a common technique for about 100 years.
I am guessing that this is a permanent magnet motor.
In general it is excess current that burns out motors. If you have a situation where lower voltage causes more current you may have a problem. This is more likely on loads such as compressors that may stall and not be able to start on reduced voltage.
For a fan you should have no problems.
respectfully

 

[Skogsgurra]

Agree. No problems. But don't expect your fan to output much air.

Gunnar Englund

http://www.gke.org

 

[powerjunx]

definitely, i agree to waross!

Moola, it seems you dont have to worry.

 

[zekeman]

The undervoltage problem is for AC motors only where the undervoltage condition causes inadequate starting torque and stalling problems leading to overheat of the motor and subsequent failure.
DC motors have inherent high starting torques (0 back emf) and are not so encumbered.

 

[ScottyUK]

zekeman,

Are you forgetting the problem of operation at high slip as a result of undervoltage? This causes relatively high frequency currents to exist in the rotor which then becomes very hot, cooking the bearings and stator insulation.

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