1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 497A Secondary Protectors for Communications CircuitsUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUT
2、HORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Secondary Protectors for Communications Circuits, UL 497A Third Edition, Dated March 20, 2001 Summary of Topics This revision of ANSI/UL 497A is being issued to reaffirm ANSI approval of the Standa
3、rd. Text that has been changed in any manner or impacted by ULs electronic publishing system is marked with a vertical line in the margin. Changes in requirements are marked with a vertical line in the margin and are followed by an effective date note indicating the date of publication or the date o
4、n which the changed requirement becomes effective. The revisions are substantially in accordance with Proposal(s) on this subject dated October 19, 2012. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, electro
5、nic, mechanical photocopying, recording, or otherwise without prior permission of UL. UL provides this Standard as is without warranty of any kind, either expressed or implied, including but not limited to, the implied warranties of merchantability or tness for any purpose. In no event will UL be li
6、able for any special, incidental, consequential, indirect or similar damages, including loss of prots, lost savings, loss of data, or any other damages arising out of the use of or the inability to use this Standard, even if UL or an authorized UL representative has been advised of the possibility o
7、f such damage. In no event shall ULs liability for any damage ever exceed the price paid for this Standard, regardless of the form of the claim. Users of the electronic versions of ULs Standards for Safety agree to defend, indemnify, and hold UL harmless from and against any loss, expense, liability
8、, damage, claim, or judgment (including reasonable attorneys fees) resulting from any error or deviation introduced while purchaser is storing an electronic Standard on the purchasers computer system. The requirements in this Standard are now in effect, except for those paragraphs, sections, tables,
9、 gures, and/or other elements of the Standard having future effective dates as indicated in the note following the affected item. The prior text for requirements that have been revised and that have a future effective date are located after the Standard, and are preceded by a SUPERSEDED REQUIREMENTS
10、 notice. DECEMBER 13, 2012 UL 497A tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL DECEMBER 13, 2012 UL 497A tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM U
11、L MARCH 20, 2001 (Title Page Reprinted: December 13, 2012) 1 UL 497A Standard for Secondary Protectors for Communications Circuits First Edition January, 1990 Second Edition January, 1996 Third Edition March 20, 2001 This ANSI/UL Standard for Safety consists of the Third Edition including revisions
12、through December 13, 2012. The most recent designation of ANSI/UL 497A as a Reaffirmed American National Standard (ANS) occurred on December 13, 2012. ANSI approval for a standard does not include the Cover Page, Transmittal Pages, Title Page, or effective date information. Comments or proposals for
13、 revisions on any part of the Standard may be submitted to UL at any time. Proposals should be submitted via a Proposal Request in ULs On-Line Collaborative Standards Development System (CSDS) at http:/. ULs Standards for Safety are copyrighted by UL. Neither a printed nor electronic copy of a Stand
14、ard should be altered in any way. All of ULs Standards and all copyrights, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2012 UNDERWRITERS LABORATORIES INC. ANSI/UL 497A-2004 (R2012)UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER RE
15、PRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL JUNE 14, 2004 SECONDARY PROTECTORS FOR COMMUNICATIONS CIRCUITS - UL 497A 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .7 2 General 8
16、 2.1 Components .8 2.2 Units of measurement .8 2.3 Undated references .8 3 Glossary .9 CONSTRUCTION 4 General .12 5 Product Assembly 12 6 Enclosures 13 6.1 General 13 6.2 Enclosure top openings 16 6.3 Enclosure side openings .16 6.4 Enclosure bottom openings .19 7 Internal Materials 19 8 Accessibili
17、ty and Electric Shock .20 9 Mechanical Assembly 26 10 Protection Against Corrosion .27 11 Cords .27 11.1 Strain relief 27 11.2 Bushings 27 12 Current-Carrying Parts 28 13 Internal Wiring 28 13.1 General .28 13.2 Splices and connections 29 14 Interconnecting Cords and Cables 29 14.1 General .29 14.2
18、Separation of circuits .30 14.3 Terminal and connectors 31 15 Insulating Material 31 16 Printed-Circuit Board 31 17 Overcurrent (Overload) Devices 32 18 Spacings 32 RISK OF INJURY TO PERSONS 19 General 33 20 Modular Jacks 33 21 Sharp Edges .34 22 Stability 35 23 Protection of Service Personnel 36 JU
19、NE 14, 2004 SECONDARY PROTECTORS FOR COMMUNICATIONS CIRCUITS - UL 497A 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL PERFORMANCE 24 General 36 25 Breakdown Voltage Measurement Test 40 26 Impulse Voltage Measurement Test .41 27 Overvoltage
20、 Test .42 27.1 General .42 27.2 Test method .45 28 Endurance Conditioning .48 29 Component Temperature Test 48 30 Drop Test 51 31 Impact Test 51 32 Crush Test .52 33 Strain Relief Test .52 34 Leakage Current Test .52 35 Dielectric Voltage-Withstand Test .54 36 Rain Test 55 37 Maximum Moment Measurem
21、ent Test .58 38 Weatherometer and Micro Tensile Strength Test .58 39 Thermal Aging and Flame Test .59 40 Electric Shock Current Test 60 MANUFACTURING AND PRODUCTION-LINE TEST 41 Dielectric Voltage-Withstand Test .63 MARKING 42 General 66 43 Installation Instructions 67 44 Instruction Manual 68 APPEN
22、DIX A Standards for ComponentsA1 APPENDIX B INFORMATION RELATING TO THE TESTING LABORATORY DIELECTRIC VOLTAGE-WITHSTAND TEST (TYPE TEST) AND THE PRODUCTION-LINE DIELECTRIC VOLTAGE-WITHSTAND TEST (ROUTINE TEST) B1 Purpose .B1 B2 Testing Laboratory Dielectric Voltage-Withstand Test (Type Test) B1 B3 P
23、roduction-Line Dielectric Voltage-Withstand Test (Routine Test) B2 B4 Production-Line Dielectric Voltage-Withstand Tester Performance (Sensitivity) .B3 B4.1 General .B3 B4.2 Voltage Regulation (For the 1-Second Factory Test Only) B4 MARCH 20, 2001 SECONDARY PROTECTORS FOR COMMUNICATIONS CIRCUITS - U
24、L 497A 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL MARCH 20, 2001 SECONDARY PROTECTORS FOR COMMUNICATIONS CIRCUITS - UL 497A 5 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT P
25、ERMISSION FROM UL This page intentionally left blank. JUNE 14, 2004 SECONDARY PROTECTORS FOR COMMUNICATIONS CIRCUITS - UL 497A 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover secondary prote
26、ctors for use in single- or multiple-pair-type communications circuits that are intended to be installed in accordance with Article 800 of the National Electrical Code, ANSI/NFPA 70. 1.2 Secondary protectors are intended to be used in the protected side of telecommunications networks that have an op
27、erating rms voltage to ground less than 150 volts and installed or used in accordance with the National Electrical Code, NFPA 70. 1.3 These requirements do not cover telephone protectors that are covered by the Standard for Protectors for Paired-Conductor Communications Circuits, UL 497. These requi
28、rements do not cover telephone equipment such as telephone answering devices, residential telephone instruments, telephone dialers, cordless telephones, key systems, and private-branch exchange equipment that is covered by the Standard for Telephone Equipment, UL 1459. 1.4 These requirements do not
29、cover cellular telephones or other receiver/transmitter-type devices. Equipment of this type is covered by the Standard for Radio Receivers, Audio Systems, and Accessories, UL 1270. 1.5 These requirements may be used, directly or by reference, to investigate portions of other equipment not classied
30、as telecommunications equipment accessories and that may be connected to a telecommunications network, insofar as they may be applicable to such equipment. 1.6 These requirements do not cover wires and cables intended to be permanently installed in a building in accordance with Article 800 of the Na
31、tional Electrical Code, NFPA 70. 1.7 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 re or of electric shock or injury to persons shall be evaluated using approp
32、riate 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 conict with specic requirements or provisions of this standard does not compl
33、y 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. JUNE 14, 2004 SECONDARY PROTECTORS FOR COMMUNICATIONS CIRCUITS - UL 497A 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR F
34、URTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 2 General 2.1 Components 2.1.1 Except as indicated in 2.1.2, a component of a product covered by this standard shall comply with the requirements for that component. See Appendix A for a list of standards covering components used in the
35、products covered by this standard. 2.1.2 A component is not required to comply with a specic requirement that: a) Involves a feature or characteristic not required in the application of the component in the product covered by this standard, or b) Is superseded by a requirement in this standard. 2.1.
36、3 A component shall be used in accordance with its rating established for the intended conditions of use. 2.1.4 Specic components are incomplete in construction features or restricted in performance capabilities. Such components are intended for use only under limited conditions, such as certain tem
37、peratures not exceeding specied limits, and shall be used only under those specic conditions. 2.2 Units of measurement 2.2.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory or approximate information. 2.2.2 Unless otherwise indicated, all voltage and curr
38、ent values specied in this standard are root-mean-square (rms). 2.3 Undated references 2.3.1 Any undated reference to a code or standard appearing in the requirements of this standard shall be interpreted as referring to the latest edition of that code or standard. MARCH 20, 2001 SECONDARY PROTECTOR
39、S FOR COMMUNICATIONS CIRCUITS - UL 497A 8UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 3 Glossary 3.1 For the purpose of this standard the following denitions apply. 3.2 EARTH GROUND A conducting connection, whether intentional or unintent
40、ional, between an electrical circuit or electrical equipment and the earth, or to some conducting body that serves in place of the earth. 3.3 ELECTRICAL ENERGY HIGH CURRENT LEVELS (POWER SUPPLIES) Electrical energy that is capable of causing damage or risk of injury to persons (other than by electri
41、c shock) is determined to exist when, between a live part and an adjacent dead-metal part or between live parts of opposite polarity, there exists a potential of not less than 30 volts rms or 42.4 volts peak (AC or DC) and either: a) An available continuous power level of not less than 250 volt-ampe
42、res or b) A reactive energy level of not less than 20 joules. For example, a tool or other metal short-circuiting a component can cause a burn or a re when enough energy is available at the component to vaporize, melt, or more than warm the metal. 3.4 ENCLOSURE The word enclosure refers only to part
43、s that house or cover: a) Uninsulated live parts that involve a risk of electric shock or b) Parts that involve a risk of re, electrical energy/high-current levels, or injury to persons. An enclosure may be an integral part of a component, a separate item or part of an outer cabinet. 3.5 FIELD-WIRIN
44、G TERMINAL A terminal to which a telephone circuit may be connected by an installer in the eld. A eld-wiring terminal may consist of a screw-type terminal, quick-connect insulation stripping system, or plug/jack arrangement. 3.6 FIXED OR STATIONARY EQUIPMENT Equipment that is not easily moved, and i
45、s intended to be moved from one place to another only when de-energized. Fixed equipment is usually fastened or secured to a building. 3.7 GROUNDING Establishing an intentional electrically conductive connection between an electrical circuit or electrical equipment and the earth ground or to some co
46、nducting body that serves in place of the earth. 3.8 LONGITUDINAL VOLTAGE (May also be called Common Mode Voltage) When applied to telecommunications conductors, the voltage common to both tip and ring conductors, or the connection points of such conductors, as measured with regard to earth ground.
47、3.9 METALLIC VOLTAGE (May also be called Differential Mode Voltage) When applied to telecommunications conductors, the voltage as measured between tip and ring conductors, of the same telecommunications pair, or the connection points of such tip and ring conductors, with no reference to earth ground
48、. 3.10 NETWORK OPERATING VOLTAGES Telecommunications networks normally operate at voltages of 56.5 volts DC or less, unless the source impedance is over 1600 ohms. For equipment connected to a single tip and ring pair, alerting and test voltages higher than 56.5 volts are intermittent and will be pr
49、esent over less than 1 percent of the usage of the equipment. Some telecommunications MARCH 20, 2001 SECONDARY PROTECTORS FOR COMMUNICATIONS CIRCUITS - UL 497A 9UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL equipment, such as PBX and Key systems, may have a greater percentage of usage or operate at a higher voltage (such as T type lines). Maximum ringing voltages may not exceed 150 volts as dened by Article 725 of the National E
