UL 746C
Standard for Polymeric Materials - Use in Electrical Equipment Evaluations

DETAILS
Edition Number:6SCC Approved:--
Edition Date:2004-09-10DOD Approved: 1988-11-03
Price Code:AANSI Approved: 2017-05-19
Type:ulstd

  • SCOPE

    1 Scope

    1.1 These requirements cover parts made of polymeric materials that are used in electrical equipment and describe the various test procedures and their use in the testing of such parts and equipment.

    1.2 These requirements do not cover the specific insulating systems that are covered by the requirements contained in the Standard for Systems of Insulating Materials, General, UL 1446.

    1.3 Test procedures are provided herein for the evaluation of polymeric materials in specific applications. These test procedures include references to data obtained from small-scale property tests conducted under standard conditions as well as other practical means of evaluation.

    1.4 Unless otherwise indicated, parts made by Additive-Manufacturing (AM) Technology shall be evaluated by subjecting the end-product part or test specimens cut from the end-product part to the specified test. For preselection purposes, test specimens printed in the specified dimensions or cut to the specified dimensions from a printed part may represent the end product when the same production conditions are used.

  • TABLE OF CONTENTS
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    • Cover
    • Transmittal
    • Table of Contents
      • Body
        • INTRODUCTION
          • 1 Scope
          • 2 General
          • 3 Glossary
        • ENCLOSURES
          • 4 General
          • 5 Portable Unattended Household Equipment – Alternate Path
            • 5.1 General
            • 5.2 Electrical connections
            • 5.3 Materials adjacent to connections
            • 5.4 Wire, tubing, sleeving and tape
        • ELECTRICAL INSULATION
          • 6 Material Property Considerations
            • 6.1 General
            • 6.2 Evaluation of Materials Not Meeting Preselection Test Performance Levels in Table
          • 7 Internal Barriers
        • PERFORMANCE CRITERIA
          • 8 General
        • ELECTRICAL
          • 9 Comparative Tracking Index (CTI)
          • 10 Dielectric Strength
          • 11 High Current Arc Resistance to Ignition (HAI)
          • 12 Hot-Wire Ignition (HWI) – Abnormal Overload Test or Glow-Wire End-Product Test
            • 12.1 General
            • 12.2 Abnormal overload test
            • 12.3 Glow-wire end-product test (GWEPT)
          • 13 Inclined Plane Tracking
          • 14 Volume Resistivity
        • FLAMMABILITY
          • 15 Flammability – 12 mm Flame
          • 16 Flammability – 20 mm (3/4-Inch) Flame
          • 17 Flammability – 127 mm (5 Inch) Flame
          • 18 Enclosure Flammability – 746-5VS
            • 18.1 Test criteria
          • 19 Enclosure Flammability – Large Surface Area Considerations
          • 20 Flame-Retardant Coatings
            • 20.1 General
            • 20.2 Test criteria
        • MECHANICAL
          • 21 Crushing Resistance
          • 22 Resistance to Impact
        • DIMENSIONAL CHANGE OF POLYMERIC PARTS
          • 23 Creep
        • PERMANENCE
          • 24 Permanence
            • 24.1 General
            • 24.2 Vicat softening point
            • 24.3 Heat deflection temperature
            • 24.4 Ball pressure temperature
          • 25 Ultraviolet Light Exposure
          • 26 Water Exposure and Immersion
            • 26.1 General
            • 26.2 Dimensional change
        • SPECIAL END-USE CONSIDERATIONS
          • 27 Abnormal Operation
          • 28 Severe Conditions
        • THERMAL
          • 29 Mold Stress-Relief Distortion
          • 30 Input to Motor
          • 31 Strain-Relief Test after Mold Stress-Relief Distortion
          • 32 Temperature Considerations – General
          • 33 Functional-Use Temperature Indices
          • 34 Generic Thermal Indices
          • 35 Relative Thermal Index
          • 36 Relative Thermal Capability
          • 37 Relative Thermal Capability (Alternate)
          • 38 Temperature Excursions Beyond the Maximum Use Temperature
        • SPECIALIZED APPLICATIONS
          • 39 General – Adhesives
          • 40 Function Analysis
          • 41 Program of Investigation
            • 41.1 End-product evaluation
            • 41.2 Effect of environmental conditions
          • 42 Coil Forms
          • 43 Conformal Coatings
          • 43A Conformal Coatings
        • METALLIZED PARTS
          • 44 General
          • 45 Ductile Coatings
          • 46 Brittle Coatings
        • TEST PERFORMANCE
          • 47 General
            • 47.1 Details
            • 47.2 Voltmeters
            • 47.3 Cheesecloth indicators
            • 47.4 Supply-circuit voltage and frequency
          • 48 End-Product Arc Resistance Test
          • 49 Abnormal Overload Test
          • 50 Flammability – 12 mm Flame Test
          • 51 Flammability – 20 mm (3/4 Inch) Flame Test
          • 52 Flammability – 127 mm (5 inch) Flame Test
          • 53 Enclosure Flammability – 746-5VS Test
            • 53.1 Apparatus
            • 53.2 Plaque conditioning
          • 54 Flame-Retardant Coatings Test
            • 54.1 Specimen conditioning
            • 54.2 Test methods
            • 54.3 Other considerations
          • 55 Crushing Resistance Test
          • 56 Resistance to Impact Test
          • 57 Ultraviolet Light Exposure Test
            • 57.1 Apparatus
            • 57.2 Method
          • 58 Water Exposure and Immersion Test
          • 59 Abnormal Operation Test
          • 60 Severe Conditions Test
          • 61 Mold Stress-Relief Distortion Test
          • 62 Ball Pressure Test on End-Product
          • 63 Input to Motors Test
          • 64 Relative Thermal Capability
          • 65 Relative Thermal Capability (Alternate)
          • 66 Temperature Excursions Beyond the Maximum Use Temperature
          • 67 Temperature Considerations – Illustrative Example
          • 68 Temperature Considerations – Illustrative Example (Alternate RTC)
          • 69 Adhesives – Specialized Applications
            • 69.1 General
            • 69.2 As-received test
            • 69.3 Effect of temperature
            • 69.4 Effect of humidity
            • 69.5 Effect of cold
            • 69.6 Effect of cyclic conditions
            • 69.7 Other test considerations
        • COIL FORMS
          • 70 Conformal Coating Test
          • 70A Conformal Coating Test
          • 71 Tape Adhesion Test
            • 71.1 General
            • 71.2 Samples
            • 71.3 Coating Thickness Measurement
            • 71.4 Sample Preparation
            • 71.5 Conditioning
            • 71.6 Results
          • 72 Leakage Current Test
          • 73 Glow-Wire End-Product Test
            • 73.1 General
            • 73.2 Significance
            • 73.3 Apparatus – Deleted
            • 73.4 Specimens – Deleted
            • 73.5 Conditioning – Deleted
            • 73.6 Procedure – Deleted
        • MARKING
          • 74 General
    • APPENDIX A Guidelines for Evaluation of Substitute Polymeric Materials