Siemens SIRIUS 3RU Series User manual

GerätehandbuchManual
Industrial Controls
Protection Devices
SIRIUS - Thermal Overload Relays SIRIUS 3RU / Electronic Overload Relays SIRIUS 3RB
Edition
siemens.com
09/2016

SIRIUS 3RU thermal overload relays /
SIRIUS 3RB electronic overload relays
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Industrial Controls
Protection devices
SIRIUS 3RU thermal overload
relays / SIRIUS 3RB electronic
overload relays
Manual
09/2016
A5E03656507420A/RS
-AB/003
Introduction
1
Standards
2
Product description
3
Product combinations
4
Functions
5
Configuration
6
Mounting
7
Connection
8
Operation
9
Accessories
10
Technical data
11
Circuit diagrams
12
Types of coordination
A
References
B
Dimension drawings
(dimensions in mm)
C

Siemens AG
Division Digital Factory
Postfach 48 48
90026 NÜRNBERG
GERMANY
3ZX1012-0RU20-5AC1
Ⓟ
09/2016 Subject to change
Copyright © Siemens AG 2011.
All rights reserved
Legal information
Warning notice system
This manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent
damage to property. The notices referring to your personal safety are highlighted in the manual by a safety alert
symbol, notices referring only to property damage have no safety alert symbol. These notices shown below are
graded according to the degree of danger.
DANGER
indicates that death or severe personal injury will result if proper precautions are not taken.
WARNING
indicates that death or severe personal injury may result if proper precautions are not taken.
CAUTION
indicates that minor personal injury can result if proper precautions are not taken.
NOTICE
indicates that property damage can result if proper precautions are not taken.
If more than one degree of danger is present, the warning notice representing the highest degree of danger will
be used. A notice warning of injury to persons with a safety alert symbol may also include a warning relating to
property damage.
Qualified Personnel
The product/system described in this documentation may be operated only by
personnel qualified
for the specific
task in accordance with the relevant documentation, in particular its warning notices and safety instructions.
Qualified personnel are those who, based on their training and experience, are capable of identifying risks and
avoiding potential hazards when working with these products/systems.
Proper use of Siemens products
Note the following:
WARNING
Siemens products may only be used for the applications described in the catalog and in the relevant technical
documentation. If products and components from other manufacturers are used, these must be recommended
or approved by Siemens. Proper transport, storage, installation, assembly, commissioning, operation and
maintenance are required to ensure that the products operate safely and without any problems. The permissible
ambient conditions must be complied with. The information in the relevant documentation must be observed.
Trademarks
All names identified by ® are registered trademarks of Siemens AG. The remaining trademarks in this publication
may be trademarks whose use by third parties for their own purposes could violate the rights of the owner.
Disclaimer of Liability
We have reviewed the contents of this publication to ensure consistency with the hardware and software
described. Since variance cannot be precluded entirely, we cannot guarantee full consistency. However, the
information in this publication is reviewed regularly and any necessary corrections are included in subsequent
editions.

SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
Manual, 09/2016, A5E03656507420A/RS-AB/003 5
Table of contents
1 Introduction............................................................................................................................................. 9
1.1 Responsibility of the user for system configuration and functionality .......................................9
1.2 Purpose of the manual..............................................................................................................9
1.3 Advantages through energy efficiency....................................................................................10
1.4 Required basic knowledge......................................................................................................10
1.5 Scope of the manual ...............................................................................................................10
1.6 Siemens Industry Online Support ...........................................................................................11
1.7 Further documentation............................................................................................................12
1.8 DataMatrix code......................................................................................................................13
1.9 Siemens Industry Online Support app....................................................................................13
1.10 Recycling and disposal ...........................................................................................................14
1.11 Technical Assistance ..............................................................................................................14
2 Standards ............................................................................................................................................. 15
2.1 Standards................................................................................................................................15
3 Product description ............................................................................................................................... 17
3.1 Introduction .............................................................................................................................17
3.2 Versions ..................................................................................................................................19
3.3 Applications.............................................................................................................................21
3.4 3RU21 thermal overload relays ..............................................................................................23
3.5 3RB20 electronic overload relays ...........................................................................................28
3.6 3RB21 electronic overload relays ...........................................................................................32
3.7 3RB30 solid-state overload relays ..........................................................................................36
3.8 3RB31 solid-state overload relays ..........................................................................................41
4 Product combinations............................................................................................................................ 47
5 Functions.............................................................................................................................................. 49
5.1 Protection against overload, phase failure, and phase asymmetry........................................49
5.1.1 Functional principle.................................................................................................................49
5.1.2 Inverse-time delayed overload release...................................................................................50
5.1.3 Tripping classes ......................................................................................................................50
5.1.4 Tripping characteristics...........................................................................................................51

Table of contents
SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
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5.2 Ground-fault protection in the case of 3RB21 / 3RB31 ......................................................... 54
5.3 Auxiliary contacts ................................................................................................................... 55
5.4 Indication of the operating state............................................................................................. 56
5.5 Self-monitoring (3RB20 / 3RB21 and 3RB30 / 3RB31 only) ................................................. 56
5.6 Additional functions ................................................................................................................ 57
6 Configuration ........................................................................................................................................ 59
6.1 SIRIUS system configurator................................................................................................... 59
6.2 Overload relays in motor feeders........................................................................................... 60
6.2.1 Motor protection with overload relay...................................................................................... 60
6.2.2 Overview of combinable 3RT contactors ............................................................................... 61
6.2.3 Normal and heavy-duty starting ............................................................................................. 62
6.2.4 Contactor assembly for star-delta (wye-delta) start ............................................................... 63
6.2.5 Operation with frequency converters ..................................................................................... 64
6.3 Short-circuit protection ........................................................................................................... 65
6.4 Protecting explosion-protected motors .................................................................................. 66
6.5 Safety instructions for use in hazardous areas (3RB) ........................................................... 67
6.5.1 General information ............................................................................................................... 67
6.5.2 Installation and commissioning.............................................................................................. 69
6.5.3 Safety data............................................................................................................................. 74
6.5.4 Maintenance and repair ......................................................................................................... 75
6.5.5 Warranty................................................................................................................................. 75
6.5.6 Further information................................................................................................................. 75
6.6 Application environment......................................................................................................... 76
7 Mounting............................................................................................................................................... 81
7.1 Mounting options.................................................................................................................... 81
7.2 Minimum clearances and mounting position.......................................................................... 82
7.3 Mounting/Disassembly........................................................................................................... 83
7.3.1 Thermal and electronic overload relays (S00 / S0)................................................................ 83
7.3.2 Thermal and electronic overload relays (S2 / S3).................................................................. 88
7.3.3 Electronic overload relays (S6) .............................................................................................. 90
7.3.4 Solid state overload relays (S10 / S12) ................................................................................. 95
8 Connection ........................................................................................................................................... 99
8.1 Connection............................................................................................................................. 99
8.2 Connection of 3RU21 overload relay................................................................................... 102
8.3 Connection of 3RB20 / 3RB21 and 3RB30 / 3RB31 overload relays .................................. 102
8.4 Connection cross-sections................................................................................................... 103
8.4.1 Conductor cross-sections for screw-type connection systems............................................ 103
8.4.2 Conductor cross-sections for spring-loaded connection systems ....................................... 110
8.4.3 Conductor cross-sections for ring cable lug connection system.......................................... 112

Table of contents
SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
Manual, 09/2016, A5E03656507420A/RS-AB/003 7
9 Operation............................................................................................................................................ 115
9.1 Setting the current.................................................................................................................115
9.2 Setting the tripping class/ground-fault detection (3RB21 / 3RB31) ......................................116
9.3 RESET after release .............................................................................................................117
9.4 TEST function .......................................................................................................................120
9.5 Response of the auxiliary contacts .......................................................................................121
10 Accessories ........................................................................................................................................ 123
10.1 Accessories...........................................................................................................................123
10.2 Terminal support for stand-alone assembly..........................................................................124
10.2.1 Description ............................................................................................................................124
10.2.2 Mounting/Disassembly..........................................................................................................125
10.3 Mechanical remote RESET ..................................................................................................129
10.3.1 Release slide ........................................................................................................................129
10.3.1.1 Description ............................................................................................................................129
10.3.1.2 Mounting/Disassembly..........................................................................................................130
10.3.2 Cable release........................................................................................................................131
10.3.2.1 Description ............................................................................................................................131
10.3.2.2 Mounting/Disassembly..........................................................................................................132
10.4 Module for electrical remote RESET (3RU21 only) ..............................................................134
10.4.1 Description ............................................................................................................................134
10.4.2 Connecting remote reset ......................................................................................................134
10.4.3 Mounting/Disassembly..........................................................................................................135
10.5 Sealable cover ......................................................................................................................136
10.5.1 Description ............................................................................................................................136
10.5.2 Mounting ...............................................................................................................................137
10.6 Covers for ring cable lug connections...................................................................................139
10.6.1 Description ............................................................................................................................139
10.7 Terminal cover for cable lug connection and busbar connection .........................................140
10.7.1 Description ............................................................................................................................140
10.7.2 Mounting ...............................................................................................................................141
10.8 Terminal covers for box terminal block .................................................................................142
10.8.1 Description ............................................................................................................................142
10.8.2 Mounting ...............................................................................................................................142
10.9 Box terminal block.................................................................................................................143
10.9.1 Description ............................................................................................................................143
10.9.2 Mounting ...............................................................................................................................144
11 Technical data .................................................................................................................................... 147
11.1 Technical data in Siemens Industry Online Support.............................................................147
11.2 Overview tables ....................................................................................................................148

Table of contents
SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
8Manual, 09/2016, A5E03656507420A/RS-AB/003
11.3 Performance features .......................................................................................................... 148
11.3.1 General data ........................................................................................................................ 148
11.3.2 Protection functions - overview ............................................................................................ 149
11.3.3 Equipment ............................................................................................................................ 150
11.3.4 Features of overload relays ................................................................................................. 151
12 Circuit diagrams...................................................................................................................................153
12.1 CAx data .............................................................................................................................. 153
12.2 Internal circuit diagrams 3RU2............................................................................................. 154
12.3 3RB20 internal circuit diagrams........................................................................................... 156
12.4 3RB21 internal circuit diagrams........................................................................................... 157
12.5 Internal circuit diagrams 3RB30........................................................................................... 158
12.6 Internal circuit diagrams 3RB31........................................................................................... 160
12.7 Wiring examples................................................................................................................... 162
A Types of coordination...........................................................................................................................165
B References ..........................................................................................................................................167
B.1 References........................................................................................................................... 167
B.2 Manuals - SIRIUS Modular System ..................................................................................... 168
B.3 More information .................................................................................................................. 170
C Dimension drawings (dimensions in mm) .............................................................................................171
C.1 CAx data .............................................................................................................................. 171
C.2 Dimension drawings for 3RU21 thermal overload relays .................................................... 172
C.3 Dimension drawings for 3RB20 / 3RB21 electronic overload relay ..................................... 180
C.4 Dimension drawings for 3RB30/3RB31 electronic overload relays ..................................... 182
C.5 Drilling diagram for 3RT contactors ..................................................................................... 194
C.6 Dimension drawings and drilling plan for 3RU29.6 stand-alone assembly supports........... 198
Index ...................................................................................................................................................203

SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
Manual, 09/2016, A5E03656507420A/RS-AB/003 9
Introduction
1
1.1
Responsibility of the user for system configuration and functionality
3RU21 thermal overload relays have been designed to provide current-dependent protection
for loads with normal starting against impermissibly high temperature rises due to overload,
phase asymmetry or phase failure.
3RB20 / 3RB21 and 3RB30 / 3RB31 electronic overload relays with internal power supply
have been designed to provide current-dependent protection for loads with normal starting
and heavy starting against impermissibly high temperature rises due to overload, phase
asymmetry or phase failure.
Siemens AG, its regional offices, and associated companies (hereinafter referred to as
"Siemens") cannot guarantee all the properties of an overall installation or machine that has
not been designed by Siemens.
Nor can Siemens assume liability for recommendations that appear or are implied in the
following description. No new guarantee, warranty, or liability claims beyond the scope of the
Siemens general terms of supply are to be derived or inferred from the following description.
Note
With regard to the design of a system, comply with all valid national installation specifications
and standards.
1.2
Purpose of the manual
This manual describes the 3RU2 and 3RB2 / 3RB3 overload relays and provides the
following information:
●Information for integrating the overload relays into the system environment.
●Information on necessary hardware components.
●Information on installing, connecting and operating the overload relays.
●Technical information such as dimension drawings and unit wiring diagrams.
The information in this manual enables you to configure and commission the overload relays.

Introduction
1.3 Advantages through energy efficiency
SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
10 Manual, 09/2016, A5E03656507420A/RS-AB/003
1.3
Advantages through energy efficiency
Siemens offers you a unique portfolio for efficient energy management in industry – a
process that serves to optimally shape your energy requirement. Operational energy
management is subdivided into three phases:
●Identifying
●Evaluating
●Realizing
Siemens supports you with suitable hardware and software solutions in every phase of a
project.
More information can be found on the Internet
(http://www.automation.siemens.com/mcms/industrial-controls/en/energy-efficiency).
The 3RB30/3RB31 electronic overload relays make the following contribution to energy
efficiency in an overall installation:
●Reduced intrinsic power loss
●Reduced control cabinet heat development
●Smaller control cabinet air conditioning units required
Figure 1-1 Overview of the energy management process
1.4
Required basic knowledge
To understand these operating instructions you should have a general knowledge of
automation engineering and low-voltage switchgear.
1.5
Scope of the manual
The manual is valid for these overload relays. It contains a description of the devices that is
valid at the time of publication.

Introduction
1.6 Siemens Industry Online Support
SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
Manual, 09/2016, A5E03656507420A/RS-AB/003 11
1.6
Siemens Industry Online Support
Information and Service
In Siemens Industry Online Support, you can obtain up-to-date information from our global
support database quickly and simply. To accompany our products and systems, we offer a
wealth of information and services that provide support in every phase of the lifecycle of your
machine or plant – from planning and implementation, through commissioning, up to
maintenance and modernization:
●Product support
●Application examples
●Services
●Forum
●mySupport
Link:
Siemens Industry Online Support (https://support.industry.siemens.com/cs/ww/en)
Product support
You will find here all the information and comprehensive know-how covering all aspects of
your product:
●
FAQs
Our answers to frequently asked questions.
●
Manuals/operating instructions
Read online or download, available as PDF or individually configurable.
●
Certificates
Clearly sorted according to approving authority, type and country.
●
Characteristic curves
For support in planning and configuring your system.
●
Product announcements
The latest information and news concerning our products.
●
Downloads
You can find here updates, service packs, HSPs and much more for your product.
●
Application examples
Function blocks, background and system descriptions, performance statements,
demonstration systems, and application examples, clearly explained and represented.
●
Technical data
Technical product data for support in planning and implementing your project.
Link:
Product support (https://support.industry.siemens.com/cs/ww/en/ps)

Introduction
1.7 Further documentation
SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
12 Manual, 09/2016, A5E03656507420A/RS-AB/003
mySupport
With "mySupport", your personal workspace, you get the very best out of your Industry
Online Support. Everything to enable you to find the right information every time.
The following functions are now available:
●
Personal messages
Your personal mailbox for exchanging information and managing your contacts
●
Inquiries
Use our online form for specific solution suggestions, or send your technical inquiry
directly to a specialist in Technical Support
●
Notifications
Make sure you always have the latest information - individually tailored to your needs
●
Filters
Simple management and re-use of your filter settings from Product Support and the
Technical Forum
●
Favorites / Tags
Create your own knowledge database by assigning "Favorites" and "Tags" to documents
– simply and efficiently
●
Entries last viewed
Clear presentation of your last viewed entries
●
Documentation
Configure your individual documentation from different manuals – quickly and without
complications
●
Personal data
Change personal data and contact information here
●
CAx data
Simple access to thousands of items of CAx data such as 3D models, 2D dimension
drawings, EPLAN macros and much more
1.7
Further documentation
To install and connect the overload relays, you require the operating instructions of the
overload relays used.
You can find a list of operating instructions and an overview of the manuals pertaining to the
SIRIUS modular system in the Appendix "References (Page 167)".

Introduction
1.8 DataMatrix code
SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
Manual, 09/2016, A5E03656507420A/RS-AB/003 13
1.8
DataMatrix code
A Data Matrix code has been lasered onto 3RB3 electronic overload relay devices and 3RU2
thermal overload relays.
The Data Matrix codes are standardized in ISO/IEC 16022. The Data Matrix codes on
Siemens devices use ECC200 coding for powerful error correction.
The following information is stored in the Data Matrix code:
1P
Article number
+
S
Location
/
Date
Serial
number
Data identifier
User content
Separator
User content
Separator
User
content
User
content
Note
The information content is displayed without spaces.
This machine-readable information simplifies and accelerates handling of the respective
devices.
As well as fast access to the serial numbers of the respective devices for unique
identification, the Data Matrix codes simplify communication with Siemens Technical
Support.
1.9
Siemens Industry Online Support app
Siemens Industry Online Support app
You can use the Siemens Industry Online Support app to access all the device-specific
information available on the Siemens Industry Online Support portal for a particular article
number, including operating instructions, manuals, datasheets, FAQs etc.
The Siemens Industry Online Support app is available for iOS, Android or Windows Phone
devices. You can download the app from the following links:
Link for Android
Link for iOS
Link for Windows Phone

Introduction
1.10 Recycling and disposal
SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
14 Manual, 09/2016, A5E03656507420A/RS-AB/003
1.10
Recycling and disposal
These devices can be recycled thanks to their low pollutant content. For environmentally-
friendly recycling and disposal of your electronic waste, please contact a company certified
for the disposal of electronic waste.
1.11
Technical Assistance
Up-to-the-minute information
You can obtain further assistance by calling the following numbers:
Technical Assistance:
Telephone: [phone] (8 a.m. to 5 p.m. CET)
Fax: [phone]
or on the Internet at:
E-mail: (mailto:[e-mail])
Internet: (http://www.siemens.com/sirius/technical-assistance)

SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
Manual, 09/2016, A5E03656507420A/RS-AB/003 15
Standards
2
2.1
Standards
Applicable standards
3RU21 thermal overload relays and 3RB20 / 3RB21 and 3RB30 / 3RB31 electronic overload
relays meet the requirements of the following standards:
Table 2- 1 Standards
Device standards •IEC/EN 60947-1
•IEC/EN 60947-4-1
•IEC/EN 60947-5-1
•UL 60947-4-1
•CSA C 22.2
EMC standard 3RB30°/ 3RB31 electronic overload relays additionally fulfill the EMC
standards specified in IEC 60947-4-1.
Reference
Other standards that 3RU and 3RB overload relays conform to are listed in chapter
Technical data (Page 147). SIRIUS components have been approved by a whole range of
bodies for various sectors (shipbuilding, etc.). An up-to-date list of approvals is provided in
the appendix of the Siemens IC 10 Catalog - "SIRIUS Industrial Controls". You will find more
information and downloadable certificates on the Internet
(https://support.industry.siemens.com/cs/ww/en).

Standards
2.1 Standards
SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
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SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
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Product description
3
3.1
Introduction
3RU21 thermal overload relays
3RU21 thermal overload relays up to 100 A have been designed to provide current-
dependent protection for loads with normal starting against impermissibly high temperature
rises due to overload, phase asymmetry or phase failure.
An overload or phase failure results in an increase of the motor current beyond the set rated
motor current. Via heating elements, this current rise increasingly heats up the bimetal strips
located inside the device. The deflection of these bimetal strips eventually activates the
auxiliary contacts via a release mechanism. The contacts then disconnect the load via a
contactor. (The contactor function is not an integral component of the overload relay).
3RB20 / 3RB21 and 3RB30 / 3RB31 electronic overload relays
3RB20 / 3RB21 electronic overload relays up to 630 A and 3RB30 / 3RB31 electronic
overload relays up to 115 A with internal power supply have been designed to provide
current-dependent protection for loads with normal starting and heavy starting against
impermissibly high temperature rises due to overload, phase asymmetry or phase failure.
An overload, phase asymmetry or a phase failure results in an increase of the motor current
beyond the set rated motor current.
This rise in current is detected by the current transformers integrated into the devices and
evaluated by corresponding electronic circuits which then output a pulse to the auxiliary
contacts. The contacts then disconnect the load via a contactor. (The contactor function is
not an integral component of the overload relay).
In addition to current-dependent protection for loads against impermissibly high temperature
rise caused by overload, phase asymmetry, and phase failure, 3RB21 and 3RB31 electronic
overload relays feature internal ground-fault detection (not possible in conjunction with
contactor assemblies for star-delta (wye-delta) start). This provides protection of loads
against high-impedance faults to ground caused by damaged insulation, moisture,
condensation, etc.
System integration
The overload relays have been matched to the contactors in the 3RT series both electrically
and mechanically and can be integrated in the feeder by means of direct mounting. 3RU2
thermal overload relays are available in sizes S00 to S3 up to 100 A. 3RB30 and 3RB31
electronic overload relays are available in sizes S00 to S3 up to 115 A. 3RB20 and 3RB21
electronic overload relays are available in sizes S6 to S10 / S12 up to 630 A.

Product description
3.1 Introduction
SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
18 Manual, 09/2016, A5E03656507420A/RS-AB/003
Connection systems
The overload relays are available with the following connection system options:
●Screw-type connection system
●Spring-loaded connection system (sizes S2 and S3 auxiliary circuit only)
●Ring cable lug connection technology (3RU21 only: main circuit and auxiliary circuit in
sizes S00 and S0; main circuit in size S3 only)
3RB3 (sizes S2 and S3) and 3RB2 (size S6) electronic overload relays are also available in
through-hole technology with straight-through transformer. As an alternative, 3RB20 / 3RB21
electronic overload relays in sizes S6 to S10 / S12 can be connected to the main circuit via
busbars.

Product description
3.2 Versions
SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
Manual, 09/2016, A5E03656507420A/RS-AB/003 19
3.2
Versions
Sizes, setting ranges, and device versions
The table below provides an overview of the various sizes in which 3RU21 thermal overload
relays and 3RB20 / 3RB21 and 3RB30 / 3RB31 electronic overload relays are available. The
maximum rated currents, the minimum and maximum setting ranges, and the available
tripping classes are listed for each individual size.
Table 3- 1 3RU21 thermal overload relays
Size
Width
Current range
Rated operating
voltage Ue
Rated frequency
Trip class
S00
45 mm
0.11 to 16 A
690 V AC 50/60 Hz CLASS 10
S0 45 mm 1.8 to 40 A
S2 55 mm 11 to 80 A CLASS 10 or
CLASS 10A
S3 70 mm 28 ... 100 A 690 V AC CLASS 10
Table 3- 2 3RB20 / 3RB30 electronic overload relays
Size
Width
Current range
Rated operating
voltage Ue
Rated frequency
Trip class
S00
45 mm
0.1 to 16 A
690 V AC 50/60 Hz CLASS 10E or 20E
(fixed)
S0
45 mm
0.1 to 40 A
S2 55 mm 12.5 to 80 A 690 V AC
Through-hole
technology: 1000
V AC
S3
70 mm
12.5 ... 115 A
1000 V AC
S6
120 mm
50 ... 200 A
690 V AC
S10 / S12 145 mm 55 ... 250 A to
160 ... 630 A
690 V AC

Product description
3.2 Versions
SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
20 Manual, 09/2016, A5E03656507420A/RS-AB/003
Table 3- 3 3RB21 / 3RB31 electronic overload relays
Size Width Current range Rated operating
voltage Ue
Rated frequency Trip class
S00 45 mm 0.1 to 16 A 690 V AC 50/60 Hz CLASS 5E, 10E, 20E,
30E (adjustable)
S0 45 mm 0.1 to 40 A
S2 55 mm 12.5 to 80 A 690 V AC
Through-hole
technology: 1000
V AC
S3 70 mm 12.5 ... 115 A 1000 V AC
S6 120 mm 50 ... 200 A 690 V AC
S10 / S12 145 mm 55 ... 250 A to
160 ... 630 A
690 V AC
3RB30 / 3RB31 electronic overload relays have approximately the same dimensions as
3RU21 thermal overload relays. As a result, the thermal overload relays can be replaced
easily with the electronic variant 3RB30/3RB31. This is necessary, for example, if increased
overload protection is required (wide setting ranges (1:4), for example, or even reduced
power loss and, as a result, minimized energy consumption).