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  • BS 7535:1992

    Withdrawn A Withdrawn Standard is one, which is removed from sale, and its unique number can no longer be used. The Standard can be withdrawn and not replaced, or it can be withdrawn and replaced by a Standard with a different number.

    Guide to the use of electrical apparatus complying with BS 5501 or BS 6941 in the presence of combustible dusts

    Available format(s):  Hardcopy, PDF

    Withdrawn date:  01-08-2007

    Language(s):  English

    Published date:  15-08-1992

    Publisher:  British Standards Institution

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

    Committees responsible
    Foreword
    Guide
    Section 1. General
    1.1 Scope
    1.2 Definitions
    1.3 Classification of hazardous areas
    1.4 Properties of combustible dusts
    1.5 Other hazards
    Section 2. Principles for selection of apparatus and
                systems
    2.1 General
    2.1.1 Selection according to apparatus construction
    2.1.2 Selection according to surface temperature
    2.1.3 Selection for use within the dust containment
    2.2 Selection of apparatus complying with BS 5501 :
           Part 2 (oil immersion 'o')
    2.3 Selection of apparatus complying with BS 5501 :
           Part 3 (pressurized apparatus 'p')
    2.4 Selection of apparatus complying with BS 5501 :
           Part 4 (powder filling 'q')
    2.5 Selection of apparatus complying with BS 5501 :
           Part 5 (flameproof enclosure 'd')
    2.6 Selection of apparatus complying with BS 5501 :
           Part 6 (increased safety 'e')
    2.7 Selection of apparatus and systems in accordance
           with BS 5501 Part 7 and 9 respectively
           (intrinsically safe apparatus and systems 'i')
    2.8 Selection of apparatus complying with BS 5501 :
           Part 8 (encapsulation 'm')
    2.9 Selection of apparatus complying with BS 6941
           (with type of protection N)
    Section 3. Installation of apparatus and systems
    3.1 General
    3.2 Installation of apparatus complying with
           BS 5501 : Part 2 (oil immersion 'o')
    3.3 Installation of apparatus complying with
           BS 5501 : Part 3 (pressurized apparatus 'p')
    3.4 Installation of apparatus complying with
           BS 5501 : Part 4 (powder filling 'q')
    3.5 Installation of apparatus complying with
           BS 5501 : Part 5 (flameproof enclosure 'd')
    3.6 Installation of apparatus complying with
           BS 5501 : Part 6 (increased safety 'e')
    3.7 Installation of apparatus and systems complying
           with BS 5501 : Parts 7 and 9 respectively
           (intrinsically safe apparatus and systems 'i')
    3.8 Installation of apparatus complying with
           BS 5501 : Part 8 (encapsulation 'm')
    3.9 Installation of apparatus complying with BS 6941
           (with type of protection 'N')
    Section 4. Inspection, testing and maintenance of
                apparatus and installations
    4.1 General
    4.2 Inspection, testing and maintenance of apparatus
           complying with BS 5501 : Part 2 (oil immersion
           'o')
    4.3 Inspection, testing and maintenance of apparatus
           complying with BS 5501 : Part 3 (pressurized
           apparatus 'p')
    4.4 Inspection, testing and maintenance of apparatus
           complying with BS 5501 : Part 4 (powder filling
           'q')
    4.5 Inspection, testing and maintenance of apparatus
           complying with BS 5501 : Part 5 (flameproof
           enclosure 'd')
    4.6 Inspection, testing and maintenance of apparatus
           complying with BS 5501 : Part 6 (increased safety
           'e')
    4.7 Inspection, testing and maintenance of apparatus
           and systems complying with BS 5501 : Parts 7 and
           9 respectively (intrinsically safe apparatus
           and systems 'i')
    4.8 Inspection, testing and maintenance of apparatus
           complying with BS 5501 : Part 8 (encapsulation
           'm')
    4.9 Inspection, testing and maintenance of apparatus
           complying with BS 6941 (with type of protection
           N)
    Tables
    1 Ip rating requirements and impact strength of
           apparatus complying with BS 5501 and BS 6941
    2 Minimum action on pressure failure
    3 Minimum conductor sizes
    4 Minimum clearances
    5 Characteristics to be met and failures to be
           taken into consideration for individual cable
           types
    6 Inspection schedule for all apparatus
    7 Additional inspection schedule for apparatus
           with additional protection
    8 Class of insulating material and limiting
           temperature
    Figures
    1 Identification of zones on drawings
    2 Minimum tE time for motors in relation to IA/IN
    3 Self-contained apparatus (F.2): paging system
    4 Simple apparatus (F.3.4): thermocouple with
           direct deflection indicator
    5 Certified associated apparatus
    6 Certified apparatus (F.3.2) with compatible
           parameters
    7 Other combinations of certified apparatus for
           solenoid valve: barrier
    8 Certified systems for microphone and loudspeaker
           system
    9 Typical procedural stages for intrinsically safe
           installations
    10 Conventional limit switch installation
    11 Conventional level switch installation
    12 Limit switches in common multicore possibly
           subject to mechanical damage (type A cable)
    13 Limit switches connected via a multicore
           adequately supported and protected (type B cable)
    14 Limit switch and float switch in individually
           screened circuits bonded at different points
           (type A or B cable)
    15 Different circuits within an overall screen
           bonded at one point (type B cable)
    16 Typical installation of a screened and armoured
           cable
    Appendices
    A Procedure for area classification
    B Properties of combustible dusts
    C Light metal construction and the associated
           frictional sparking risks
    D Selection of increased safety 'e' cage motors and
           associated protection devices
    E Illustrations of typical intrinsically safe
           installations
    F Certification of intrinsically safe electrical
           apparatus and systems
    G Examples of the more common combinations of
           'earthed' circuits and screens
    H Test for restricted-breathing

    Abstract - (Show below) - (Hide below)

    Electrical apparatus intended for use in explosive gas atmospheres under conditions where the hazard will be from combustible dust. Electrical apparatus is considered acceptable if it operates safely in an enclosure with a maximum dust layer thickness of five millimetres on its external surface.

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

    Committee EXL/31
    Development Note Supersedes 88/29111 DC (10/2005)
    Document Type Standard
    Publisher British Standards Institution
    Status Withdrawn

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

    EEMUA 186 : 2016 A PRACTITIONER'S HANDBOOK FOR POTENTIALLY EXPLOSIVE ATMOSPHERES
    BS IEC 61831:1999 On-line analyser systems. Guide to design and installation

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

    IP 6 : 4ED 82 ASPHALTENES IN OIL - PRECIPITATION WITH NORMAL HEPTANE
    IP 54 : 1942 SETTING POINT
    BS 6480:1988 Specification for impregnated paper-insulated lead or lead alloy sheathed electric cables of rated voltages up to and including 33000 V
    BS 5958-2:1991 Code of practice for control of undesirable static electricity Recommendations for particular industrial situations
    BS 5501-9:1982 Electrical apparatus for potentially explosive atmospheres Specification for intrinsically safe electrical systems \'i\'
    BS 5501-4:1977 Electrical apparatus for potentially explosive atmospheres Powder filling \'q\'
    BS 6467-2:1988 Electrical apparatus with protection by enclosure for use in the presence of combustible dusts Guide to selection, installation and maintenance
    BS 7430:1991 Code of practice for earthing
    BS 5501-7:1977 Electrical apparatus for potentially explosive atmospheres Intrinsic safety \'i\'
    BS 5501-6:1977 Electrical apparatus for potentially explosive atmospheres Increased safety \'e\'
    BS 5501-1:1977 Electrical apparatus for potentially explosive atmospheres General requirements
    IP 5 : 1942 ASH FROM GREASE
    BS 5501-5:1977 Electrical apparatus for potentially explosive atmospheres Flameproof enclosure \'d\'
    BS 5345-2:1983 Code of practice for selection, installation and maintenance of electrical apparatus for use in potentially explosive atmospheres (other than mining applications or explosive processing and manufacture) Classification of hazardous areas
    BS 4568-2:1970 Specification for steel conduit and fittings with metric threads of ISO form for electrical installations Fittings and components
    BS 6467-1:1985 Electrical apparatus with protection by enclosure for use in the presence of combustible dusts Specification for apparatus
    BS 5501-8:1988 Electrical apparatus for potentially explosive atmospheres Encapsulation \'m\'
    BS 6656:1991 Guide to prevention of inadvertent ignition of flammable atmospheres by radio-frequency radiation
    BS 5501-2:1977 Electrical apparatus for potentially explosive atmospheres Oil immersion \'o\'
    BS 4568-1:1970 Specification for steel conduit and fittings with metric threads of ISO form for electrical installations Steel conduit, bends and couplers
    BS 5345-1:1989 Code of practice for selection, installation and maintenance of electrical apparatus for use in potentially explosive atmospheres (other than mining applications or explosive processing and manufacture) General recommendations
    BS 4121:1967 Specification for mechanical cable glands for rubber and plastics insulated cables
    BS 6941:1988 Specification for electrical apparatus for explosive atmospheres with type of protection N
    BS 5501-3:1977 Electrical apparatus for potentially explosive atmospheres Pressurized apparatus \'p\'
    BS 7361-1:1991 Cathodic protection Code of practice for land and marine applications
    IEC 60079-15:2010 Explosive atmospheres - Part 15: Equipment protection by type of protection "n"
    BS 4999-101:1987 General requirements for rotating electrical machines Specification for rating and performance
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