UL 497
Standard for Protectors for Paired-Conductor Communications Circuits

DETAILS
Edition Number:7SCC Approved:--
Edition Date:2001-04-25DOD Approved: --
Price Code:AANSI Approved: 2013-07-19
Type:ulstd

  • SCOPE

    1 Scope

    1.1 These requirements cover protectors for paired-conductor communications circuits to be used in accordance with Article 800 of the National Electrical Code, NFPA 70.

    1.2 As covered by these requirements, a communications circuit protector consists of single- and multiple-pair air gap arresters, gas tube arresters, or solid state arresters, with or without fuses or other voltage-limiting devices. A circuit protector is intended to protect equipment, wiring, and personnel against the effects of excessive potentials and currents in telephone lines caused by lightning, contacts with power conductors, power induction, and rises in ground potential.

    1.3 This standard does not cover the following:

    a)    Lightning protective devices for the protection of secondary distribution wiring systems and equipment.

    b)    Antenna discharge units for radio- and television-receiving appliances.

    c)    Lightning conductor and air terminals for connection of lightning rods for building protection.

    d)    Protectors for fire alarm signaling circuits that are covered by the Standard for Protectors for Data Communications and Fire-Alarm Circuits, UL 497B.

    e)    Secondary Protectors for Communications Circuits, UL 497A.

    f)    Transient Voltage Surge Suppressors, UL 1449.

    1.4 A product that contains features, characteristics, components, materials, or systems new or different from those covered by the requirements in this standard, and that involves a risk of fire or of electric shock or injury to persons shall be evaluated using appropriate additional component and end-product requirements to maintain the level of safety as originally anticipated by the intent of this standard. A product whose features, characteristics, components, materials, or systems conflict with specific requirements or provisions of this standard does not comply with this standard. Revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard.

  • TABLE OF CONTENTS
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    • Cover
    • Transmittal
    • Table of Contents
    • UL Foreword
      • Body
        • INTRODUCTION
          • 1 Scope
          • 2 General
            • 2.1 Components
            • 2.2 Units of measurement
            • 2.3 Undated references
          • 3 Glossary
        • CONSTRUCTION
          • 4 General
          • 5 Enclosures
            • 5.1 General
            • 5.2 Sheet metal
            • 5.3 Nonmetallic
            • 5.4 Arrester well sizes
          • 6 Protection Against Corrosion
            • 6.1 General
            • 6.2 Outdoor use
            • 6.3 Grommets
          • 7 Field-Wiring Connections
            • 7.1 General
            • 7.2 Field-wiring terminals
            • 7.3 Field-wiring connections (appliqué units)
            • 7.4 Field-wiring leads and cables
            • 7.5 Field-wiring terminals accessible to users
          • 8 Components
            • 8.1 General
            • 8.2 Arrester assemblies
            • 8.3 Electrical insulation material
          • 9 Spacings
          • 10 Fuses
        • PERFORMANCE
          • 11 General
          • 12 Line Fuse Current-Carrying Capacity Tests
          • 13 Line Fuse Overload Test
          • 14 Line Fuse Short-Circuit Test
          • 15 Instrument Fuse Limited Current Tests
          • 16 Breakdown Voltage Measurement Test
          • 17 Impulse Sparkover Voltage Measurement Test
          • 18 Limited Short-Circuit Current Test
          • 19 Abnormal Operation Test
          • 20 Endurance Conditioning Test
          • 21 Induced Low-Current Test
          • 22 Sneak Current Test
          • 23 Gas Tube Arrester Vent Test
          • 24 Distortion Test
          • 25 Flame Test
          • 26 Ultraviolet Light and Water Exposure
          • 27 Low Temperature Drop
          • 28 Rubber Materials Tensile Strength and Elongation Tests
          • 29 Air Oven Aging Test
          • 30 Ozone Exposure Test
          • 31 Indoor Corrosion Test
            • 31.1 General
            • 31.2 Hydrogen sulfide exposure
            • 31.3 Sulfur dioxide-carbon dioxide
          • 32 Outdoor Corrosion Test
            • 32.1 General
            • 32.2 Hydrogen sulfide exposure
            • 32.3 Sulfur dioxide-carbon dioxide exposure
            • 32.4 Salt spray exposure
          • 33 Jarring Test
          • 34 Water Spray Test
          • 35 Drop Test
          • 36 Impact Test (Polymeric Enclosures)
          • 37 Cover Replacement Test
          • 38 Strain Relief Test
          • 39 Replacement Arresters Installation Test
          • 40 Appliqué Assemblies Installation Test
          • 41 Dielectric Voltage-Withstand Test
        • MANUFACTURING AND PRODUCTION-LINE TESTS
          • 42 Gas Tube Seal Test Program
            • 42.1 General
            • 42.2 Breakdown voltage measurements – gas tube seal test program
            • 42.3 Mechanical stress test
            • 42.4 Thermal aging
            • 42.5 Thermal shock
            • 42.6 Service life
            • 42.7 Over-pressure leak test
          • 43 General
          • 44 Breakdown Voltage Test
        • MARKING
          • 45 General
        • INSTALLATION INSTRUCTIONS
          • 46 General