Functions; Soft Starting - Siemens SIRIUS 3RW50 Manual

Functions

7.1

Soft starting

Operating principle
A voltage ramp is used to implement soft starting. The 3RW50 soft starter increases the
motor voltage from a parameterizable starting voltage to the line voltage within a definable
ramp up time.
Application
● Systems in which a startup of the drive without interfering jerky movements is required.
● E.g. pumps or small fans
Voltage characteristic
①
②
U
N
U
S
t
1
t
2
SIRIUS 3RW50 soft starter
Manual, 09/2019, A5E35628455002A/RS-AA/001
Voltage ramp with short ramp up time t
Voltage ramp with long ramp up time t
Line voltage
Parameterizable starting voltage
Short ramp up time
Long ramp up time
1
2
7
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