Skip to content
Please enter a keyword to search

  • IEC TR 61912-2:2009

    Current The latest, up-to-date edition.

    Low-voltage switchgear and controlgear - Over-current protective devices - Part 2: Selectivity under over-current conditions

    Available format(s):  Hardcopy, PDF, PDF 3 Users, PDF 5 Users, PDF 9 Users

    Language(s):  English

    Published date:  13-05-2009

    Publisher:  International Electrotechnical Committee

    Add To Cart

    Table of Contents - (Show below) - (Hide below)

    FOREWORD
    INTRODUCTION
    1 Scope
    2 Normative references
    3 Terms, definitions and abbreviated terms
      3.1 Alphabetical index of terms
      3.2 Terms and definitions
      3.3 Abbreviated terms
    4 Scope of selectivity requirements
      4.1 General
      4.2 Motor protection circuit-breaker/Manual motor starter
    5 Selectivity determination
      5.1 Circuit-breaker as UD
          5.1.1 Selectivity between circuit-breakers
          5.1.2 Selectivity between a circuit-breaker (UD) and
                a fuse to IEC 60269-1 (DD)
          5.1.3 CB/CPS - Selectivity between a circuit-breaker
                to IEC 60947-2 (UD) and a CPS to IEC 60947-6-2
                (DD)
          5.1.4 Circuit-breaker/MOR - Selectivity between a
                circuit-breaker (UD) and a motor protection
                overload relay to IEC 60947-4-1 or
                IEC 60947-4-2 (DD)
      5.2 Fuse(s) to IEC 60269-1 as UD
          5.2.1 Fuse/circuit-breaker - Selectivity between a fuse
                to IEC 60269-1 (UD) and a circuit-breaker (DD)
          5.2.2 FU/FU - Selectivity between fuses to IEC 60269-1
                (UD and DD)
          5.2.3 FU/CPS - Selectivity between fuse(s) to IEC 60269-1
                (UD) and a CPS to IEC 60947-6-2 (DD)
          5.2.4 FU/MOR - Selectivity between fuse(s) to IEC 60269-1
                (UD) and a motor overload protection relay to
                IEC 60947-4-1 or IEC 60947-4-2 (DD)
    6 Residual current devices (RCDs)
      6.1 General
      6.2 Selectivity - RCD/RCD
          6.2.1 Selectivity between RCDs in the case of
                earth-leakage current
          6.2.2 Selectivity between RCDs in the case of
                earth-fault (ground-fault) current
    7 Zone Selective Interlocking (ZSI)
      7.1 General
      7.2 Operating principle
      7.3 Example
    8 Over-current protection relay (OCR) - Single input energizing
      quantity measuring relays with dependent or independent time
    Annex A (informative) - Examples of selectivity between
            over-current protection devices Examples of the grades
            of selectivity applicable to circuit-breakers
    Annex B (informative) - Standing loads - Effect of standing
            loads on selectivity in the overload zone
    Bibliography

    Abstract - (Show below) - (Hide below)

    IEC 61912-2:2009(E), which serves as an application guide for the determination of selectivity between over-current protective devices of low-voltage switchgear and controlgear, summarises the definitions of the terminology and provides examples of application.

    General Product Information - (Show below) - (Hide below)

    Committee TC 121/SC 121A
    Development Note Stability Date: 2015. (10/2012)
    Document Type Technical Report
    Publisher International Electrotechnical Committee
    Status Current

    Standards Referenced By This Book - (Show below) - (Hide below)

    UNE-HD 50573.5.57:2014 Co-ordination of electrical equipment for protection, isolation, switching and control
    EN 61439-1:2011 Low-voltage switchgear and controlgear assemblies - Part 1: General rules
    PD IEC/TR 61439-0:2013 Low-voltage switchgear and controlgear assemblies Guidance to specifying assemblies
    CLC/TR 60269-5:2011 Low-voltage fuses - Part 5: Guidance for the application of low-voltage fuses
    IEC TR 61439-0:2013 Low-voltage switchgear and controlgear assemblies - Part 0: Guidance to specifying assemblies
    I.S. HD 50573-5-57:2014 CO-ORDINATION OF ELECTRICAL EQUIPMENT FOR PROTECTION, ISOLATION, SWITCHING AND CONTROL
    ENA ER G87 : ISSUE 2 2015 GUIDELINES FOR THE PROVISION OF LOW VOLTAGE CONNECTIONS TO MULTIPLE OCCUPANCY BUILDINGS
    IEC TR 60269-5:2014 Low-voltage fuses - Part 5: Guidance for the application of low-voltage fuses
    I.S. EN 61439-1:2011 LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLIES - PART 1: GENERAL RULES (IEC 61439-1:2011)
    UNE-HD 60364-5-53:2016 Low-voltage electrical installations - Part 5-53: Selection and erection of electrical equipment - Switchgear and controlgear
    S.R. HD 60364-5-53:2015 LOW-VOLTAGE ELECTRICAL INSTALLATIONS - PART 5-53: SELECTION AND ERECTION OF ELECTRICAL EQUIPMENT - SWITCHGEAR AND CONTROLGEAR
    BS PD88-5(2010) : 2010 LOW-VOLTAGE FUSES - PART 5: GUIDANCE FOR THE APPLICATION OF LOW-VOLTAGE FUSES
    IEC 61439-1:2011 Low-voltage switchgear and controlgear assemblies - Part 1: General rules
    09/30204029 DC : 0 BS EN 61439-1 - LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLIES - PART 1: GENERAL RULES
    IEC 61439-1:2020 Low-voltage switchgear and controlgear assemblies - Part 1: General rules
    16/30301661 DC : 0 BS EN 61439-1 ED3.0 - LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLIES - PART 1: GENERAL RULES
    HD 50573-5-57:2014 Co-ordination of electrical equipment for protection, isolation, switching and control
    S.R. CLC/TR 60269-5:2011 LOW-VOLTAGE FUSES - PART 5: GUIDANCE FOR THE APPLICATION OF LOW-VOLTAGE FUSES
    UNE-EN 61439-1:2012 Low-voltage switchgear and controlgear assemblies - Part 1: General rules
    PD IEC/TR 60269-5:2010 Low-voltage fuses Guidance for the application of low-voltage fuses
    BS EN 61439-1:2011 Low-voltage switchgear and controlgear assemblies General rules
    HD 60364-5-53:2015/A11:2017 LOW-VOLTAGE ELECTRICAL INSTALLATIONS - PART 5-53: SELECTION AND ERECTION OF ELECTRICAL EQUIPMENT - SWITCHGEAR AND CONTROLGEAR

    Standards Referencing This Book - (Show below) - (Hide below)

    IEC TR 61912-1:2007 Low-voltage switchgear and controlgear - Overcurrent protective devices - Part 1: Application of short-circuit ratings
    IEC 60947-6-2:2002+AMD1:2007 CSV Low-voltage switchgear and controlgear - Part 6-2: Multiple function equipment - Control and protective switching devices (or equipment) (CPS)
    IEC 60269-4:2009+AMD1:2012+AMD2:2016 CSV Low-voltage fuses - Part 4: Supplementary requirements forfuse-links for the protection of semiconductor devices
    IEC TR 62350:2006 Guidance for the correct use of residual current-operated protective devices (RCDs) for household and similar use
    IEC 60947-4-1:2009+AMD1:2012 CSV Low-voltage switchgear and controlgear - Part 4-1: Contactors and motor-starters - Electromechanical contactors and motor-starters
    IEC 60050-441:1984 International Electrotechnical Vocabulary (IEV) - Part 441: Switchgear, controlgear and fuses
    IEC 60269-2:2013+AMD1:2016 CSV Low-voltage fuses - Part 2: Supplementary requirements for fuses for use by authorized persons (fuses mainly for industrial application) - Examples of standardized systems of fuses A to K
    IEC 61008-1:2010+AMD1:2012+AMD2:2013 CSV Residual current operated circuit-breakers without integral overcurrent protection for household and similar uses (RCCBs) - Part1: General rules
    IEC 60269-1:2006+AMD1:2009+AMD2:2014 CSV Low-voltage fuses - Part 1: General requirements
    IEC 60050-442:1998 International Electrotechnical Vocabulary (IEV) - Part 442: Electrical accessories
    IEC 61009-1:2010+AMD1:2012+AMD2:2013 CSV Residual current operated circuit-breakers with integral overcurrentprotection for household and similar uses (RCBOs) - Part 1: General rules
    IEC 60269-3:2010+AMD1:2013 CSV Low-voltage fuses - Part 3: Supplementary requirements for fuses foruse by unskilled persons (fuses mainly for household or similar applications) - Examples of standardized systems of fuses A to F
    IEC 60947-1:2007+AMD1:2010+AMD2:2014 CSV Low-voltage switchgear and controlgear - Part 1: General rules
    IEC 60947-4-2:2011 Low-voltage switchgear and controlgear - Part 4-2: Contactors and motor-starters - AC semiconductor motor controllers and starters
    IEC TR 61818:2003 Application guide for low-voltage fuses
    IEC 60898-1:2015 Electrical accessories - Circuit-breakers for overcurrent protection for household and similar installations - Part 1: Circuit-breakers for a.c. operation
    IEC 60050-826:2004 International Electrotechnical Vocabulary (IEV) - Part 826: Electrical installations
    IEC 60947-2:2016 Low-voltage switchgear and controlgear - Part 2: Circuit-breakers
    IEC 60050-448:1995 International Electrotechnical Vocabulary (IEV) - Part 448: Power system protection
    View more information

    • Access your standards online with a subscription

      Features

      • Simple online access to standards, technical information and regulations
      • Critical updates of standards and customisable alerts and notifications
      • Multi - user online standards collection: secure, flexibile and cost effective