Shortly: will my stepper motor get fried during an hot summer day if outdoor?
By reading the 99% of stepper specs I found something like that:
https://i.ibb.co/Q9w1Vzd/Selection-7039.jpg
So, if the internal wire insulation can upstand up to 130 Celsius (ClassB), why the max operating temperature reported is only 50 °C ?
I’m missing something? :roll:
P.S.
The above image is from a stepper “Widely used in aircraft, ships, automobiles, antennas, solar equipment, etc” :o
50 C would be the maximum ambient temperature, not the case temperature.
Industrial steppers are designed to run with high case temperatures, 80 to 100 C is common.
Mmmmmh… so the motor-case temperature could be far higher than that, yes? It seems a reasonable heat resistance.
As stated in the document below, the motor-case surface temperature can reach 90 °C without particular problems.
https://blog.moonsindustries.com/2019/1 … roduction/
But what happens to a stepper motor inside a black plastic box in a full sunny day of August?
Inside that case the temperature could easily reach more than 90° Celsius, even if the “ambient temperature” is far lower…
Maybe the right approach would be to make cuts in the plastic box to provide some kind of internal ventilation? Yes? (But this is would be a significant problem in case of days with strong rain…)
Maybe ask the manufacturer?
Here the answer from www.omc-stepperonline.com:
Hi Giulio,
Please don’t up 50C for motor condition.
Best Regards
Bo Wang
Very concise and short answer… Maybe they have a limitation about the number of characters typed on the keyboard per daily basis? 
Inside that case the temperature could easily reach more than 90° Celsius, even if the “ambient temperature” is far lower…
The ambient temperature is the air temperature around the motor, which would be “more than 90° Celsius”.
That must not exceed 50° Celsius.
Hmmm… So I have to find a way to provide a minimum ventilation inside the box.
I think that inside a black ABS box exposed to direct sun rays in August one can easily register a temperature suitable for nuclear fusion… : ) : ) : )
