Product Description; Fields Of Application; Basic Physical Principles Of A Three-Phase Induction Motor; Three-Phase Induction Motor - Siemens SIRIUS 3RW30 Manual

Product description

3.1

Fields of application

Soft starters are used to start three-phase induction motors with reduced torque and reduced
starting current.
SIRIUS soft starter family
The SIEMENS SIRIUS soft starter family comprises three different versions with different
functionalities and prices.
3RW30 and 3RW40
Simple or standard applications are covered by the SIRIUS 3RW30 and 3RW40 soft starters
and are described in this manual.
3RW44
The SIRIUS 3RW44 soft starter is used if higher functionality is specified, e.g. communication
over PROFIBUS or the availability of measuring and monitoring values, as well as for ultra-
heavy-duty starting. The SIRIUS 3RW44 soft starter is described in a separate system
manual.
Download from 3RW44 manual
llisapi.dll?func=cslib.csinfo&lang=de&objid=21772518&caller=view).
3.2

Basic physical principles of a three-phase induction motor

SIRIUS soft starters are used to reduce the current and torque of a three-phase induction
motor during the startup process.
3.2.1

Three-phase induction motor

Fields of application
Three-phase induction motors are used in a wide range of applications in commerce, industry,
and trade owing to their simple, robust design and their minimal maintenance.
Problem
If a three-phase induction motor is started directly, its typical current and torque
characteristics can cause disturbances in the supply system and the load machine.
SIRIUS 3RW30 / 3RW40
Manual 01/2010, 535 1995-02 DS01
(http://support.automation.siemens.com/WW/
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