stepper motor overheat

[thitchen007]

Hi all,

I'm using the legacy motor CTP10xxx10 with motor drive P70530, on page18 the manual says "...If an equivalent heat sink is not used, reduce the default drive current for these motors by 25% to avoid overheating...", I did this by creating a new motor file using the file editor and entered the lower current into the box for "motor current" (the amps peak is auto-calculated). But the amount of heat is still large.

My question is: do I need to modify the "peak torque" below as well? And how?

Thanks in advance,

-chen

p.s. After I modified the motor file and performed a "Probe Stepper Motor", an error will show up, so I'm not sure the modification takes effect or not at all. Please any help is appreciated.

[Buechsenschuetz]

First, not all current settings are created equal ... the effective current through the motor may be different from what you selected by driver configuration, depending on the wiring of the motor coils.

Second, what do you call "a large amount of heat"? If the motor feels very warm when touching it with your finger, it probably has not more than 35 ... 40 deg Celsius (we do not use Fahrenheit over here...). Any motor will withstand such a temperature and even somewhat more. Check the manufacturer's data for maximum surface temperature of the motor housing, and measure it with an infrared or contact thermometer.

If the motor is supposed to run with the full amount of current with a heatsink, reducing the current by 25 p.c. probably will result in quite a bit of heat of the motor WITHOUT heatsink. Reducing the current by 25 p.c. is not too much, however if it is specified like that by the manufacturer the motor probably will not be damaged.

[thitchen007]

Many thanks for your reply, just solved the problem with an option to reduce the current when motor is idle.