Selecting Induction Motors - Siemens SIMOTICS M 1PH8 Configuration Manual

The following criteria must be taken into account when selecting the motor:
• The dynamic limits must be adhered to, i.e. all speed-torque points of the relevant load event
must lie below the relevant limiting characteristic curve.
• The thermal limits must be adhered to, i.e. the rms motor torque at the average motor speed
resulting from the duty cycle must lie below the S1 characteristic curve (continuous duty).
The rms value of the motor current within a duty cycle must be less than the rated motor
current.
• In the field-weakening range, the permissible motor torque is restricted by the voltage limit
characteristic (stability limit).
Note
Rated pulse frequencies
The rated motor data is valid only for 4 kHz (booksize or blocksize Motor Modules) or 2 kHz
(chassis motor module). Operation of the motors with rated pulse frequencies < 2 kHz is not
permitted!
6.2.3

Selecting induction motors

Characteristic curves for asynchronous motors
Speed-power diagrams P = f(n) and speed-torque diagrams M = f(n) for operation with the
SINAMICS converter system are described in the motor characteristics, see Chapter "Technical
data and characteristics" (Page 219).
Depending on the motor variant, the S1 characteristic (continuous operation) is available
from standstill to rated point with maximum possible thermal torque, or passes through
the constant-torque range. The power increases in proportion to speed depending on the
available torque.
This is then followed by a constant-power range where the field is weakened (field-
weakening range). The field-weakening range is limited by the voltage limit.
For induction motors, in addition to the S1 characteristic, the S6 characteristics are also
shown, see Chapter "Technical data and characteristics" (Page 219).
1PH8 SIMOTICS M main motors
Configuration Manual, 12/2022, A5E51895839A
Configuration
6.2 Procedure when engineering
209