Siemens 3RW44 User Manual

Device functions
7.2 Startup modes
3RW44 soft starters
Manual, 03/2017, NEB535219502000/RS-AB/008
123
Internal run-up recognition
The soft starter features internal run-up recognition. If it detects a motor run-up within the set
starting time, the ramp is canceled and the motor voltage is immediately increased to 100%
of the line voltage. The internal bypass contacts close and the thyristors are bridged.
NOTICE
The torque generated in the motor and controlled by the soft starter can never be higher
than the value of a similar direct on-line starting operation at the associated speed.
Figure 7-3 Function principle of torque control
Typical applications for torque control
Torque control is suitable for all applications, especially in cases where uniform and smooth
startup is required. For machines requiring a breakaway pulse (inverse load response, e.g. in
mills or crushers), the breakaway pulse must be set as described in chapter Breakaway
pulse in combination with the voltage ramp or torque control startup mode (Page 124). The
"Torque control+current limiting (M+current limiting)" startup mode is recommended for
heavy starting (refer to chapter Current limitation in combination with the voltage ramp or
torque control startup mode (Page 125)).

Siemens 3RW44 Specifications

General

Temperature range	-25°C to +60°C
Degree of protection	IP20
Product category	Soft starter
Product designation	3RW44
Type of voltage	AC
Protection class IP	IP20
Standards	IEC 60947-4-2
Overload class	Class 10, 20

Summary

Introduction

Basic Principles of Three-Phase Asynchronous Motors

Explains the physical principles of three-phase asynchronous motors and their starting characteristics.

Principle of Operation of 3RW44 Electronic Soft Starter

Describes how the 3RW44 soft starter uses antiparallel thyristors to control motor voltage.

Application and Use

Covers typical applications and selection criteria for 3RW44 soft starters.

Applications

Advantages

Configuration Instructions

3.1 Configuration

Details on basic configuration, including PC interface and simulation tools.

3.2 Startup Class

Explains the importance of startup class for soft starter design and selection criteria.

Application Examples for Normal Starting (CLASS 10)

Application Examples for Heavy Starting (CLASS 20)

Application Examples for Very Heavy Starting (CLASS 30)

Installation, Connection and Feeder Configuration

4.1 Installing the Soft Starter

Covers unpacking, mounting position, installation requirements, and clearances.

4.2 Design of the Feeder

Explains general feeder design, disconnectors, and contact elements.

Soft Starters in Standard Circuits

Describes connection of soft starters in standard motor feeder circuits.

Soft Starters in Inside-Delta Circuits

Details the requirements and connection for inside-delta circuit configurations.

4.3 Protection Against Short-Circuits

Explains protection methods, including type of coordination 1 and 2.

4.6 Electrical Connection

Covers control, auxiliary, and main circuit connections.

Commissioning

6.1 Menu Structure, Navigation, Changing Parameters

Guides on navigating menus and modifying parameters.

6.2 Switching On for the First Time

Provides a recommended procedure for initial device commissioning.

6.3 User-Specific Commissioning

Details steps for custom configuration, including parameter sets, motor data, and I/O.

6.4 Making Settings in the Selected Parameter Set

Covers selection and adjustment of various parameters like startup modes and coasting methods.

6.5 Other Device Functions

Device Functions

7.2 Startup Modes

Details various startup modes like Voltage Ramp, Torque Control, and Current Limitation.

7.3 Coasting Methods

Covers different stopping methods such as Coasting Down, Torque Control, and DC Braking.

7.4 Slow Speed Function

Describes operation at lower speeds and its limitations.

7.5 Current Limits for Load Monitoring

7.6 Motor Protection Functions

Details motor overload protection, tripping classes, and asymmetry limit values.

7.7 Intrinsic Device Protection

Describes the internal protection mechanisms preventing thyristor thermal overloading.

Diagnostics and Messages

8.1 Diagnostics and Messages

Provides an overview of status messages, warnings, group faults, and device faults.

PROFIBUS DP Communication Module

9.1 Introduction

9.2 Data Transfer

9.3 Installing the PROFIBUS DP Communication Module

Guides on installing the PROFIBUS DP communication module, including safety precautions.

9.4 Activating the PROFIBUS DP Communication Module and Setting the Station Address

Details activation via display or software and setting the station address.

9.5 Configuring Soft Starters

Covers configuration using GSD files and Soft Starter ES Professional software.

9.6 PROFIBUS DP Commissioning using GSD file in STEP 7

Provides an example of commissioning using GSD files in STEP 7.

9.7 Process Data and Process Images

9.8 Diagnosis via LED Display

9.9 Diagnosis with STEP 7

9.10 Data Formats and Data Sets

9.11 Identification Number (ID No.), Error Codes

9.12 Data Sets (BS)

General Technical Data

11.1 Menu Structure

11.3 Technical Data

11.3.2 Technical Data of the Power Unit

11.3.6 Feeder Component Layout (Standard Circuit)

Shows component layouts for standard circuits with fuse assignment.

11.4 Tripping Characteristics