Siemens SIRIUS 3RW30 Manual page 39

Ramp-up detection (3RW40 only)
The SIRIUS 3RW40 soft starter is equipped with an integrated ramp-up detection function. If
it detects a motor startup, the motor voltage is immediately increased to 100% of the mains
voltage. The internal bypass contacts close and the thyristors are bridged.
Figure 5-4
Typical applications for current limiting
Current limiting is used for applications with large centrifugal masses (mass inertias) and
therefore longer starting times, e.g. fans, circular saws etc.
SIRIUS 3RW30 / 3RW40
Manual, 10/2018, NEB535199502000/RS-AB/005
Current limiting with soft starter
Functions
5.1 Start modes
39