Siemens 3RK1308‑0 00‑0CP0 Series Equipment Manual page 42

Product features
5.3 Designing motor starters in conjunction with electromechanical switching devices
Remedial measures
● Delayed shutdown of the line contactor by the motor starter shutting down before the
contact (in current zero point). These voltage peaks do not occur at all and the contactor
can be shut down (de-energized) approx. 100 ms later. This also results in an increased
service life of the contactor, because it always switches without load.
● Use of RC elements on the 3 motor phases. As a consequence, the voltage peaks and
also the steep voltage rise are reduced.
Figure 5-3
The following RC elements are suitable:
● 3RK1911-6EA00 for direct attachment to the motor terminal board
● 3RK1911-6EB00 for direct attachment to the motor terminal board
● RC elements for direct attachment on the S00 contactor (3RT2916-1P*). RC elements for
load contactors larger than size S00 must be obtained through third-party manufacturers.
NOTICE
Connected motors
Observe the dimensioning of the connected motors.
42
Use of RC elements for reducing voltage peaks
Motor starter (3RK1308‑0**00‑0CP0)
Equipment Manual, 11/2019, A5E34821005002A/RS-AC/003