• BS 7626:1993

    Superseded A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.

    Specification for current transformers

    Available format(s):  Hardcopy, PDF

    Superseded date:  15-11-1999

    Language(s):  English

    Published date:  15-02-1993

    Publisher:  British Standards Institution

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

    CHAPTER I: GENERAL REQUIREMENTS APPLICABLE TO ALL CURRENT
               TRANSFORMERS
    SECTION ONE - GENERAL
    1 Scope
    2 Service conditions
    3 Definitions
    SECTION TWO - RATING AND PERFORMANCE REQUIREMENTS APPLICABLE
                  TO ALL CURRENT TRANSFORMERS
    4 Standard values of rated primary current
    5 Standard values of rated secondary current
    6 Rated continuous thermal current
    7 Standard values of rated output
    8 Short-time current ratings
    9 Limits of temperature rise
    10 Insulation requirements
    SECTION THREE - TESTS - GENERAL
    11 Classification of tests
    SECTION FOUR - TYPE TESTS
    12 Short-time current tests
    13 Temperature-rise test
    14 Impulse tests on primary windings
    15 Wet test for outdoor type transformers
    SECTION FIVE - ROUTINE TESTS
    16 Verification of terminal markings
    17 Power-frequency tests on primary windings and measurement
       of partial discharges
    18 Power-frequency tests between sections of primary and
       secondary windings and on secondary windings
    19 Test of interturn insulation
    SECTION SIX - SPECIAL TESTS
    20 Chopped lightning-impulse test on primary windings
    21 Measurement of dielectric dissipation factor
    SECTION SEVEN - MARKING
    22 Terminal markings - General rules
    23 Rating plate markings
    CHAPTER II: ADDITIONAL REQUIREMENTS FOR MEASURING CURRENT
                TRANSFORMERS
    SECTION EIGHT - GENERAL
    24 Scope
    25 Definitions
    SECTION NINE - ACCURACY REQUIREMENTS
    26 Accuracy class designation
    27 Limits of current error and phase displacement
    28 Extended current rating
    SECTION TEN - TESTS FOR ACCURACY
    29 Type tests
    30 Routine tests
    31 Instrument security current
    SECTION ELEVEN - MARKING
    32 Marking of the rating plate of a measuring current
       transformer
    CHAPTER III: ADDITIONAL REQUIREMENTS FOR PROTECTIVE CURRENT
                 TRANSFORMERS
    SECTION TWELVE - GENERAL
    33 Scope
    34 Definitions
    SECTION THIRTEEN - ACCURACY REQUIREMENTS
    35 Standard accuracy limit factors
    36 Accuracy classes
    37 Limits of error
    SECTION FOURTEEN - TESTS FOR ACCURACY
    38 Type and routine tests for current error and phase
       displacement
    39 Type tests for composite error
    40 Routine tests for composite error
    SECTION FIFTEEN - MARKING
    41 Marking of the rating plate of a protective current
       transformer
    APPENDIX A - Protective current transformers
    Annex ZA (normative) Other international publications quoted
                           in this standard with the references of
                           the relevant European publications
    Annex ZB (informative) B-Deviations
    National annex NA (informative) Original IEC text amended by
                                    CENELEC common modifications
    National annex NB (informative) Cross-references

    Abstract - (Show below) - (Hide below)

    Applicable to newly manufactured current transformers for use with electrical measuring instruments and electrical protective devices at frequencies from 15 Hz to 100 Hz.

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

    Committee PEL/38
    Development Note Supersedes BS 3938(1973). (04/2003)
    Document Type Standard
    Publisher British Standards Institution
    Status Superseded
    Superseded By
    Supersedes

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

    BS EN 61116:1995 Electromechanical equipment guide for small hydroelectric installations
    BS 7430:1998 Code of practice for earthing
    BS EN 60041:1995 Field acceptance tests to determine the hydraulic performance of hydraulic turbines, storage pumps and pump-turbines
    BS EN 61268:1996 Alternating current static var-hour meters for reactive energy (classes 2 and 3)

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

    IEC 60038:2009 IEC standard voltages
    IEC 60028:1925 International standard of resistance for copper
    HD 540.2 : 200S1 INSULATION COORDINATION - APPLICATION GUIDE
    HD 472 S1:1989/AC:2013 NOMINAL VOLTAGES FOR LOW-VOLTAGE PUBLIC ELECTRICITY SUPPLY SYSTEMS
    IEC 60085:2007 Electrical insulation - Thermal evaluation and designation
    HD 566 : 200S1 THERMAL EVALUATION AND CLASSIFICATION OF ELECTRICAL INSULATION
    IEC 60071-3:1982 Insulation co-ordination - Part 3: Phase-to-phase insulation co-ordination - Principles, rules and application guide
    IEC 60050-321:1986 International Electrotechnical Vocabulary (IEV) - Part 321: Instrument transformers
    IEC 60071-2:1996 Insulation co-ordination - Part 2: Application guide
    IEC 60044-4:1980 Instrument transformers - Part 4: Measurement of partial discharges
    IEC 60060-1:2010 High-voltage test techniques - Part 1: General definitions and test requirements
    IEC 60507:2013 Artificial pollution tests on high-voltage ceramic and glass insulators to be used on a.c. systems
    IEC 60071-1:2006+AMD1:2010 CSV Insulation co-ordination - Part 1: Definitions, principles and rules
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