• BS EN 60742:1996

    Superseded A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.

    Isolating transformers and safety isolating transformers. Requirements

    Available format(s):  Hardcopy, PDF

    Superseded date:  07-04-2003

    Language(s):  English

    Published date:  15-04-1996

    Publisher:  British Standards Institution

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

    General plan of the Standard
    Chapter 1: General requirements
    1 Scope and object
    2 Definitions
    3 General requirement
    4 General notes on tests
    5 Rating
    6 Classification
    7 Marking
    8 Protection against electric shock
    9 Change of input voltage setting
    10 Output voltage and output current under load
    11 No-load output voltage
    12 Short-circuit voltage
    13 Heating
    14 Short-circuit and overload protection
    15 Mechanical strength
    16 Protection against harmful ingress of water and
         moisture
    17 Insulation resistance and electric strength
    18 Construction
    19 Components
    20 Internal wiring
    21 Supply connection and external flexible cables and
         cords
    22 Terminals for external conductors
    23 Provision for protective earthing
    24 Screws and connections
    25 Creepage distances, clearances and distances through
         insulation
    26 Resistance to heat, abnormal heat, fire and tracking
    27 Resistance to rusting
    Appendix A
    Appendix IA Production tests
    Appendix IA Examples to be used as guide for sub-clause 8.6
    Appendix IC Examples of points of application of test
                voltages
    Appendix ID Measurement of creepage distances and
                clearances
    Appendix IE Examples of points of measurement of creepage
                distances and clearances
    Chapter II: Supplementary requirements for isolating
                transformers
    Section one - Isolating transformers for general use,
    shaver transformers and shaver supply units
    2 Definitions
    5 Rating
    7 Marking
    8 Protection against electric shock
    11 No-load output voltage
    13 Heating
    14 Short-circuit and overload protection
    15 Mechanical strength
    18 Construction
    19 Components
    21 supply connection and external flexible cables and
         cords
    22 Terminals for external conductors
    23 Provision for earthing
    Appendix II-I-A Requirements for special socket-outlets
    for shaver supply units
    Chapter III: Supplementary requirements for safety
    isolating transformers
    Section one - Safety isolating transformers for general
    use
    5 Rating
    7 Marking
    8 Protection against electric shock
    11 No-load output voltage
    21 Supply connection and external flexible cables and
         cords
    Section two - Transformers for toys
    2 Definitions
    4 General notes on tests
    5 Rating
    7 Marking
    8 Protection against electric shock
    9 Change of input voltage setting
    10 Output voltage and output current under load
    11 No-load output voltage
    12 Short-circuit voltage
    14 Short-circuit and overload protection
    15 Mechanical strength
    18 Construction
    19 Components
    21 Supply connection and external flexible cables
         and cords
    Section three - Bell transformers
    2 Definitions
    4 General notes on tests
    5 Rating
    6 Classification
    7 Marking
    8 Protection against electric shock
    10 Output voltage and output current under load
    11 No-load output voltage
    13 Heating
    14 Short-circuit and overload protection
    15 Mechanical strength
    18 Construction
    19 Components
    21 Supply connection and external flexible cables and
         cords
    22 Terminals for external conductors
    23 Provision for earthing
    Appendix II-I-A Requirements for special socket-outlets
    for shaver supply units
    Chapter III: Supplementary requirements for safety
    isolating transformers
    Section one - Safety isolating transformers for general
    use
    5 Rating
    7 Marking
    8 Protection against electric shock
    11 No-load output voltage
    21 Supply connection and external flexible cables and
         cords
    Section two - Transformers for toys
    2 Definitions
    4 General notes on tests
    5 Rating
    7 Marking
    8 Protection against electric shock
    9 Change of input voltage setting
    10 Output voltage and output current under load
    11 No-load output voltage
    12 Short-circuit voltage
    14 Short-circuit and overload protection
    15 Mechanical strength
    18 Construction
    19 Components
    21 Supply connection and external flexible cables and
         cords
    Section three - Bell transformers
    2 Definitions
    4 General notes on tests
    5 Rating
    6 Classification
    7 Marking
    8 Protection against electric shock
    10 Output voltage and output current under load
    11 No-load output voltage
    13 Heating
    14 Short-circuit and overload protection
    15 Mechanical strength
    18 Construction
    19 Components
    21 Supply connection and external flexible cables and
         cords
    22 Terminals for external conductors
    24 Screws and connections
    Section four - Transformers for class III handlamps
    2 Definitions
    5 Rating
    7 Marking
    8 Protection against electric shock
    10 Output voltage and output current under load
    11 No-load output voltage
    18 Construction
    21 Supply connection and external flexible cables and
         cords
    Figures
    Annex ZA (normative) Testing of a series of transformers
    Annex ZB (normative) Other international publications
    quoted in this standard with the references of the
    relevant European publications
    Annex ZC (normative) Special national conditions

    Abstract - (Show below) - (Hide below)

    Specifies requirements for isolating transformers and safety isolating transformers having a rated supply voltage not exceeding 1000 V a.c. and rated frequency not exceeding 500 Hz.

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

    BS 7375:1996 Code of practice for distribution of electricity on construction and building sites
    09/30205684 DC : 0 BS 7375 - CODE OF PRACTICE FOR DISTRIBUTION OF ELECTRICITY ON CONSTRUCTION AND BUILDING SITES

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

    IEC 60038:2009 IEC standard voltages
    BS 4491-1:1989 Appliance couplers for household and similar general purposes Specification of general requirements
    IEC 60884-1:2002+AMD1:2006+AMD2:2013 CSV Plugs and socket-outlets for household and similar purposes - Part1: General requirements
    BS EN 60999:1993 Connecting devices. Safety requirements for screw-type and screwless-type clamping units for electrical copper conductors
    BS EN 60068-2-32:1993 Environmental testing. Test methods Test Ed. Free fall
    BS 6004:2000 Electric cables. PVC insulated, non-armoured cables for voltages up to and including 450/750 V, for electric power, lighting and internal wiring
    IEC 60685-2-1:1980 Connecting devices (junction and/or tapping) for household and similar fixed electrical installations - Part 2: Particular requirements - Screwless terminals for connecting copper conductors without special preparation
    BS 7211:1998 Electric cables. Thermosetting insulated, non-armoured cables for voltages up to and including 450/750 V, for electric power, lighting and internal wiring, and having low emission of smoke and corrosive gases when affected by fire
    BS 6726:1998 Specification for festoon and temporary lighting cables and cords
    BS 7671(2001) : 2001 AMD 14905 REQUIREMENTS FOR ELECTRICAL INSTALLATIONS
    BS 6899:1991 Specification for rubber insulation and sheath of electric cables
    BS EN 60269-2:1995 Low-voltage fuses Supplementary requirements for fuses for use by authorized persons (fuses mainly for industrial application)
    IEC 60685-1:1980 Connecting devices (junction and/or tapping) for household and similar fixed electrical installations - Part 1: General requirements
    HD 365 : 200S3 CLASSIFICATION OF DEGREES OF PROTECTION PROVIDED BY ENCLOSURES
    BS EN 60068-2-2:2007 Environmental testing Tests. Test B. Dry heat
    BS EN 60065 : 2014 AUDIO, VIDEO AND SIMILAR ELECTRONIC APPARATUS - SAFETY REQUIREMENTS (IEC 60065:2014, MODIFIED)
    BS EN 61058-1 : 2002 SWITCHES FOR APPLIANCES - PART 1: GENERAL REQUIREMENTS
    BS EN 60269-3:1995 BS Low-voltage fuses Supplementary requirements for fuses for use by unskilled persons (fuses mainly for household and similar applications)
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