DC Motor Speed

[unclesyd]

I've lost my DC motor Expert.

What is the variance in speed between two series wound DC motors(2hp) on the same bus?

Will it vary with motor size and speed?

 

[waross]

Runaway! I hope these motors are driving fan loads.
A series motor has maximum torque at standstill. The torque drops in almost inverse relation to the speed. The speed generally may be expected to increase until the motor torque speed intersects the load torque speed. With no load centrifugal forces may damage the motor before theoretical maximum speed is reached.
Better tell us a little more about the application Syd.

Bill
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"Why not the best?"
Jimmy Carter

 

[unclesyd]

Thanks for the info that's was close to my understanding of it.
I knew about runaway DC motors, so these will always be loaded isn't very high, not pushing 2hp rating.

I was introduced to runaways very early in life when on a streetcar when something broke in the motorman's controller and the motor would wind up until someone pulled the pickup off the hot wire.