Siemens SINAMICS S120 Configuration Manual page 48

Electrical data
4.4 Definitions
Optimum operating point
Operating point at which the maximum continuous output of the motor is normally provided
at high efficiency (see figure below).
Figure 4-5
Optimum speed n
opt
Speed at which the optimum motor power is output.
If the rated speed is less than the optimum speed, the rated speed is indicated.
Optimum power P
opt
Power achieved at the optimum speed.
The rated speed is the optimum speed (see optimum speed), the optimum power
corresponds to the rated power.
48
Optimum operating point
Configuration Manual, (PFK7S), Edition 12.2006, 6SN1197-0AD16-0BP1
Synchronous Motors 1FK7