1、UL 497AISBN 0-7629-0626-XSecondary Protectors forCommunications CircuitsUnderwriters Laboratories Inc. (UL)333 Pfingsten RoadNorthbrook, IL 60062-2096UL Standard for Safety for Secondary Protectors for Communications Circuits, UL 497AThird Edition, Dated March 20, 2001UL is in the process of convert
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19、s beingviewed for their own fair and/or practical internal use.The requirements in this Standard are now in effect, except for those paragraphs, sections, tables, figures,and/or other elements of the Standard having future effective dates as indicated in the note following theaffected item. The prio
20、r text for requirements that have been revised and that have a future effective dateare located after the Standard, and are preceded by a SUPERSEDED REQUIREMENTS notice.New product submittals made prior to a specified future effective date will be judged under all of therequirements in this Standard
21、 including those requirements with a specified future effective date, unlessthe applicant specifically requests that the product be judged under the current requirements. However, ifthe applicant elects this option, it should be noted that compliance with all the requirements in thisStandard will be
22、 required as a condition of continued Listing and Follow-Up Services after the effectivedate, and understanding of this should be signified in writing.Copyright 2001 Underwriters Laboratories Inc.This Standard consists of pages dated as shown in the following checklist:Page Date1-72 .March 20, 2001A
23、1-A2 .March 20, 2001B1-B6 .March 20, 2001MARCH 20, 2001 UL 497Atr2MARCH 20, 20011UL 497AStandard for Secondary Protectors for Communications CircuitsFirst Edition January, 1990Second Edition January, 1996Third EditionMarch 20, 2001Revisions of this Standard will be made by issuing revised or additio
24、nal pagesbearing their date of issue. A UL Standard is current only if it incorporates themost recently adopted revisions, all of which are itemized on the transmittal noticethat accompanies the latest set of revised requirements.ISBN 0-7629-0626-XCOPYRIGHT 1990, 2001 UNDERWRITERS LABORATORIES INC.M
25、ARCH 20, 2001SECONDARY PROTECTORS FOR COMMUNICATIONS CIRCUITS - UL 497A2No Text on This PageCONTENTSFOREWORD .6INTRODUCTION1 Scope .72 General .82.1 Components .82.2 Units of measurement .82.3 Undated references .83 Glossary .9CONSTRUCTION4 General .125 Product Assembly .126 Enclosures .136.1 Genera
26、l .136.2 Enclosure top openings .166.3 Enclosure side openings .166.4 Enclosure bottom openings .197 Internal Materials .198 Accessibility and Electric Shock .209 Mechanical Assembly .2610 Protection Against Corrosion .2711 Cords .2711.1 Strain relief .2711.2 Bushings .2712 Current-Carrying Parts .2
27、813 Internal Wiring .2813.1 General .2813.2 Splices and connections .2914 Interconnecting Cords and Cables .2914.1 General .2914.2 Separation of circuits .3014.3 Terminal and connectors .3115 Insulating Material .3116 Printed-Circuit Board .3117 Overcurrent (Overload) Devices .3218 Spacings .32RISK
28、OF INJURY TO PERSONS19 General .3320 Modular Jacks .3321 Sharp Edges .3422 Stability .3523 Protection of Service Personnel .36MARCH 20, 2001 SECONDARY PROTECTORS FOR COMMUNICATIONS CIRCUITS - UL 497A 3PERFORMANCE24 General .3625 Breakdown Voltage Measurement Test .4026 Impulse Voltage Measurement Te
29、st .4127 Overvoltage Test .4227.1 General .4227.2 Test method .4528 Endurance Conditioning .4829 Component Temperature Test .4830 Drop Test .5131 Impact Test .5132 Crush Test .5233 Strain Relief Test .5234 Leakage Current Test .5235 Dielectric Voltage-Withstand Test .5436 Rain Test .5537 Maximum Mom
30、ent Measurement Test .5838 Weatherometer and Micro Tensile Strength Test .5839 Thermal Aging and Flame Test .5940 Electric Shock Current Test .60MANUFACTURING AND PRODUCTION-LINE TEST41 Dielectric Voltage-Withstand Test .63MARKING42 General .6643 Installation Instructions .6744 Instruction Manual .6
31、8APPENDIX AStandards for Components.A1APPENDIX B INFORMATION RELATING TO THE TESTING LABORATORY DIELECTRICVOLTAGE-WITHSTAND TEST (TYPE TEST) AND THE PRODUCTION-LINE DIELECTRICVOLTAGE-WITHSTAND TEST (ROUTINE TEST)B1 Purpose .B1B2 Testing Laboratory Dielectric Voltage-Withstand Test (Type Test) .B1B3
32、Production-Line Dielectric Voltage-Withstand Test (Routine Test) .B2B4 Production-Line Dielectric Voltage-Withstand Tester Performance (Sensitivity) .B3B4.1 General .B3B4.2 Voltage Regulation (For the 1-Second Factory Test Only) .B4MARCH 20, 2001SECONDARY PROTECTORS FOR COMMUNICATIONS CIRCUITS - UL
33、497A4MARCH 20, 2001 SECONDARY PROTECTORS FOR COMMUNICATIONS CIRCUITS - UL 497A 5No Text on This PageFOREWORDA. This Standard contains basic requirements for products covered by Underwriters Laboratories Inc. (UL)under its Follow-Up Service for this category within the limitations given below and in
34、the Scope sectionof this Standard. These requirements are based upon sound engineering principles, research, records oftests and field experience, and an appreciation of the problems of manufacture, installation, and usederived from consultation with and information obtained from manufacturers, user
35、s, inspection authorities,and others having specialized experience. They are subject to revision as further experience andinvestigation may show is necessary or desirable.B. The observance of the requirements of this Standard by a manufacturer is one of the conditions of thecontinued coverage of the manufacturers product.C. A product which complies with
