Siemens SIMODRIVE 611 Configuration Manual page 39

Figure 3-4
Fixed variables are usually used for the relative on period:
• S3 – 60%
• S3 – 40%
• S3 – 25%
The corresponding motor characteristics are provided for these specifications. The load
torque must lie below the corresponding thermal limiting curve of the motor. An overload
must be taken into consideration for load duty cycles with varying on periods.
In summary, a motor is selected as follows:
Figure 3-5
General Section for Synchronous Motors
Configuration Manual, (PJAL), 11.2005 Edition, 6SN1 197-0AD07-0BP4
S3 duty (intermittent operation without influencing starting)
Selecting motors for load duty cycles with varying on periods using a synchronous motor
as an example
Configuration
3.3 Dimensioning
3-9