Siemens 1FT7 Configuration Manual page 47

Load duty cycles with constant on period
For duty cycles with constant ON period, there are specific requirements for the torque
characteristic curve as a function of the speed, for example:
M = constant, M ~ n
Figure 2-3
These drives typically operate at a specific operating point. Drives such as these are
dimensioned for a base load. The base load torque must lie below the S1 characteristic
curve. In the event of transient overloads (e.g. when accelerating) an overload has to be
taken into consideration. The overload current must be calculated relative to the required
overload torque. The peak torque must lie below the voltage limiting characteristic.
In summary, the motor is selected as follows:
Figure 2-4
1FT7 Synchronous Motors
Configuration Manual, (PFT7S) 01/2009, 6SN1197-0AD13-0BP2
, M ~ n or P = constant.
2
S1 duty (continuous operation)
Selection of motors for load duty cycles with constant on period (examples)
Configuration
2.4 Procedure when engineering
47