UL 60079-7
Standard for Explosive Atmospheres - Part 7: Equipment Protection by Increased Safety ''e''

DETAILS
Edition Number:5SCC Approved:--
Edition Date:2017-02-24DOD Approved: --
Price Code:GANSI Approved: 2017-02-24
Type:uliec

  • SCOPE

    1 Scope

    1DV.1 Modification of Clause 1, first paragraph to replace with the following:

    1DV.1.1 This part of IEC 60079 standard specifies the requirements for the design, construction, testing and marking of electrical equipment and Ex Components with type of protection increased safety “e” intended for use in explosive gas atmospheres.

    Electrical equipment and Ex Components of type of protection increased safety “e” are either:

    a) Level of Protection “eb” (EPL “Mb” or “Gb”); or

    b) Level of Protection “ec” (EPL “Gc”)

    Level of Protection “eb” applies to equipment or Ex Components, including their connections, conductors, windings, lamps, and batteries; but not including semiconductors or electrolytic capacitors.

    NOTE 1 The use of electronic components, such as semiconductors or electrolytic capacitors, is excluded from Level of Protection “eb” as expected malfunctions could result in excessive temperatures or arcs and sparks if the internal separation distances were not applied. It is not generally practical to maintain those separation distances and maintain the function of the electronic component.

    Level of Protection “ec” applies to equipment or Ex Components, including their connections, conductors, windings, lamps, and batteries; and also including semiconductors and electrolytic capacitors.

    NOTE 2 The use of electronic components, such as semiconductors or electrolytic capacitors, is permitted in Level of Protection “ec” as these are evaluated under both normal conditions and regular expected occurrences, and are not likely to result in excessive temperatures or arcs and sparks. As the requirements for separation distances are not applied to the internal construction, commercially available electronic components are generally suitable if the external separation distances comply.

    The requirements of this standard apply to both Levels of Protection unless otherwise stated.

    For Level of Protection “eb”, this standard applies to electrical equipment where the rated voltage does not exceed 11 kV r.m.s., a.c. or d.c.

    For Level of Protection “ec”, this standard applies to electrical equipment where the rated voltage does not exceed 15 kV r.m.s., a.c. or d.c.

    NOTE 3 Short circuit currents flowing through increased safety connections of mains circuits are not considered to create a significant risk of ignition of an explosive gas atmosphere due to movement of connections as a result of mechanical stresses created by the short circuit current. Normal industrial standards require that the effects of short time high currents on the security of connections be considered. The presence of the explosive gas atmosphere does not adversely affect the security of the connection.

    NOTE 4 Any short term thermal excursions that occur as a result of electrical current excursions above normal rated currents, such as those that occur during the starting of motors, are not considered to create a significant risk of ignition of an explosive gas atmosphere due to the relatively short duration of the event and the convection that occurs during the event.

    NOTE 5 High-voltage connections and associated wiring (above 1 kV) can be susceptible to increased partial discharge activity that could be a source of ignition. Increased spacings to earthed surfaces or other connections and provision of suitable high-voltage stress relief for the terminations are typically provided.

    1DV.2 Modification of Clause 1, eighth paragraph to replace with the following:

    1DV.2.1 This standard supplements and modifies the general requirements of IEC 60079-0 UL 60079-0. Where a requirement of this standard conflicts with a requirement of IEC 60079-0 UL 60079-0, the requirement of this standard takes precedence.

    1DV.3 Addition of 1DV.3.1

    Where references are made to other IEC 60079 standards, the referenced requirements found in these standards apply as modified by any applicable U.S. National Differences.

  • TABLE OF CONTENTS
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    • Cover
    • Transmittal
    • Table of Contents
    • UL Preface
    • Deviations
    • IEC Foreword
      • EXPLOSIVE ATMOSPHERES – Part 7: Equipment protection by increased safety ''e''
        • 1 Scope
        • 2 Normative references
        • 3 Terms and definitions
        • 4 Constructional requirements
          • 4.1 Level of Protection
          • 4.2 Electrical connections
          • 4.3 Clearances
          • 4.4 Creepage distances
          • 4.5 Printed wiring boards with conformal coating, Level of Protection “ec”
          • 4.6 Solid electrical insulating materials
          • 4.7 Windings
          • 4.8 Temperature limitations
          • 4.9 Wiring internal to equipment
          • 4.10 Degrees of protection provided by enclosures
          • 4.11 Fasteners
          • 4.12ADV.1.1 Arcing or sparking contacts
        • 5 Supplementary requirements for specific electrical equipment
          • 5.1 General
          • 5.2 Electrical machines
          • 5.3 Luminaires, hand lights, or caplights
          • 5.4 Analog measuring instruments and instrument transformers
          • 5.5 Transformers other than instrument transformers
          • 5.6 Supplementary requirements for equipment incorporating cells and batteries
          • 5.7 General purpose connection and junction boxes
          • 5.8 Resistance heating equipment (other than trace heating systems)
          • 5.9 Supplementary requirements for fuses
          • 5.10 Other electrical equipment
        • 6 Type verifications and type tests
          • 6.1 Dielectric strength
          • 6.2 Rotating electrical machines
          • 6.3 Luminaires
          • 6.4 Measuring instruments and instrument transformers
          • 6.5 Transformers other than instrument transformers
          • 6.6 Verification and tests for cells and batteries of Level of Protection “eb”
          • 6.7 Verification and tests for cells and batteries of Level of Protection “ec”
          • 6.8 General purpose connection and junction boxes
          • 6.9 Resistance heating equipment
          • 6.10 Terminal insulating material tests
        • 7 Routine verifications and routine tests
          • 7.1 Dielectric tests
          • 7.2 Dielectric tests for batteries
          • 7.3 Inter-turn overvoltage tests
        • 8 Ex Component certificates
          • 8.1 General
          • 8.2 Terminals
        • 9 Marking and instructions
          • 9.1 General marking
          • 9.2 Ex Component enclosures
          • 9.3 Instructions for use
          • 9.4 Warning markings
        • 10 Documentation
    • Annex A (normative) Temperature determination of electrical machines – Methods of test and of calculation
    • Annex B (normative) Type tests for specific forms of resistance heating devices or resistance heating units (other than trace heater)
    • Annex C(informative) Cage motors – Thermal protection in service
    • Annex D (informative) Resistance heating devices and units – Additional electrical protection
    • Annex E (informative) Combinations of terminals and conductors for general purpose connection and junction boxes
    • Annex F (normative) Dimensions of copper conductors
    • Annex G (normative) Test procedure for T5 (only 8 W), T8, T10 and T12 lamps
    • Annex H (normative) Alternative separation distances for Level of Protection “ec” equipment under controlled environments
    • Annex I (informative) Application, installation, and testing considerations for Level of Protection “ec” asynchronous machines
    • Annex J (informative) Luminaires incorporating LEDs
    • Bibliography