Q.I am concerned about heat generation (surface temperature) of stepper motors (including αSTEP). Is this normal?

As long as the surface temperature of the motor case is 100 °C max., the motor can be used.
The motor insulation class is class B insulation with a permissible temperature of 130 °C for the windings. Since a temperature difference of 30 °C is expected between the inside of the motor and the surface of the case, the upper limit is 100 °C on the surface of the case.

• Please use the AZ Series with a motor case surface temperature of 80 °C or below. If the temperature of the ABZO sensor exceeds 85 °C, the motor overheat protection alarm will be triggered.

Considering the lifetime of the ball bearing of the motor bearing, mount it on a metal plate with good heat conductivity and use it at the lowest possible temperature. The lifetime of the bearing is 50,000 hours at a motor case surface temperature of 80 °C. Using at temperatures above 80 °C will shorten the lifetime of the motor. Click here for details.

Class A insulation (105 °C) is required for the UL/CSA approval condition. When applying for a set as a UL/CSA approved product, please use it at a motor case surface temperature of 75 °C max.

If surface temperature of the stepper motor is a concern, there are ways to reduce temperature rises.
Click here for details.