Stepper heat >75C sitting on bench 100 rpm

[Monte]

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Is this okay? The specsheet for the motor(s) gives -20C to 50C for ambient operating temperature.

MCG IH23014 motors wired parallel, 37vdc supply, 39k current set resistor (36k sets 3A, 62k sets 4A) Gecko 203V drivers.

Motor specs:
Parallel, 2.3 vdc/ph, 4.2 a/ph
Series, 4.7 vdc/ph, 2.1 a/ph

This seems too hot to me. Is it a function of the voltage or current, or both? 36/2.3=15.7, so it seems like the voltage isn't as much as it could be. 20*2.3=46, I'm 10 volts below that.

I've searched and read what I could, and it looks like this isn't all that hot according to some. But it is 25C over the listed specsheet ambient temperature given for the motors.

Monte

[jeffs555]

I've searched and read what I could, and it looks like this isn't all that hot according to some. But it is 25C over the listed specsheet ambient temperature given for the motors.

Ambient temperature is not a spec for how hot the motor can get, it is a spec for the temperature in the room or enclosure in which the motor can work(ie the room temperature). The actual motor temperature when operating will always be higher than ambient. At 75 degC the motor is hot, but probably not too hot.

[vladdy]

commercial motors, especially under continuous use run pretty warm, but are usually shielded...
myself, I prefer that if I place my hand on a motor it shouldn't be hot to the point of where it's uncomfortable to the touch..
while a good quality recent production motor is safer, I usually wind up with older 'surplus' or ebay motors, and I don't want to take un-neccesary risks in damaging my ebay prizes through excessive heat..

just my opinion...

enjoy.