1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 497A Secondary Protectors for Communications Circuits STANDARD FOR SAFETYUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGH
2、TED MATERIAL NOT AUTHORIZED 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 address the editori
3、al maintenance of the standard. The revisions are substantially in accordance with Proposal(s) on this subject dated December 23, 2016. Text that has been changed in any manner or impacted by ULs electronic publishing system is marked with a vertical line in the margin. All rights reserved. No part
4、of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, electronic, 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, includ
5、ing but not limited to, the implied warranties of merchantability or tness for any purpose. In no event will UL be liable 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 th
6、e inability to use this Standard, even if UL or an authorized UL representative has been advised of the possibility of 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 UL
7、s Standards for Safety agree to defend, indemnify, and hold UL harmless from and against any loss, expense, liability, 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
8、 computer system. MAY 30, 2017 UL 497A tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL MAY 30, 2017 UL 497A tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL
9、 MARCH 20, 2001 (Title Page Reprinted: May 30, 2017) 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 throug
10、h February 10, 2017. The most recent designation of ANSI/UL 497A as a Reaffirmed American National Standard (ANS) occurred on February 10, 2017. ANSI approval for a standard does not include the Cover Page, Transmittal Pages and Title Page. Comments or proposals for revisions on any part of the Stan
11、dard 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 https:/. ULs Standards for Safety are copyrighted by UL. Neither a printed nor electronic copy of a Standard should be altered in any way.
12、 All of ULs Standards and all copyrights, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2017 UNDERWRITERS LABORATORIES INC. ANSI/UL 497A-2004 (R2017)UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOU
13、T 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 2.1 Components 8 2.2 Units of me
14、asurement .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 Accessibility and Electric Shock .20 9 Mecha
15、nical 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 Separation of circuits 30 14.3
16、 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 JUNE 14, 2004 SECONDARY PROT
17、ECTORS 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 Test 42 27.1 General .42
18、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 Measurement Test .58 38 Weatherometer
19、 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 APPENDIX A Standards for Compone
20、ntsA1 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 Production-Line Dielectric V
21、oltage-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 - UL 497A 4UL COPYRIGHTED MAT
22、ERIAL 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 PERMISSION FROM UL This pag
23、e 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 protectors for use in single- o
24、r 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 operating rms voltage to gro
25、und 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 requirements do not cover telep
26、hone 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 Information Technology Equipment - Safety - Part 1: General Requirements, UL 60950-1.
27、1.4 These requirements do not cover cellular telephones or other receiver/transmitter-type devices. Equipment of this type is covered by the Standard for Audio-Video Products and Accessories, UL 1492. 1.5 These requirements may be used, directly or by reference, to investigate portions of other equi
28、pment not classied 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 Ar
29、ticle 800 of the National 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 eva
30、luated 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 conict with specic requirements or provisions of this stan
31、dard 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. MAY 30, 2017 SECONDARY PROTECTORS FOR COMMUNICATIONS CIRCUITS - UL 497A 7UL COPYRIGHTED MATERIAL NO
32、T AUTHORIZED FOR FURTHER 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 compo
33、nents used in the 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 t
34、his standard. 2.1.3 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, s
35、uch as certain temperatures 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, al
36、l voltage and current 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 S
37、ECONDARY PROTECTORS 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 inten
38、tional or unintentional, 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 (oth
39、er than by electric 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
40、than 250 volt-amperes 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 r
41、efers only to parts 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 cabine
42、t. 3.5 FIELD-WIRING 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 e
43、asily moved, and is 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 gr
44、ound or to some conducting 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
45、 to earth ground. 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 referen
46、ce to earth ground. 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 intermitt
47、ent and will be present 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, suc
48、h 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 Electrical Code for Class 2 and 3 circuits. 3.11 NONPROTECTED SIDE The portion of the loop
49、 circuit that rests on the central office or outside plant side of the primary telephone protector installed by the operating telephone company. The fault current limitation is subject to the breakdown voltage characteristics of the primary protector and its coordinated fusing system with the bridle or fuse wire with which the protector is intended to be used. 3.12 PORTABLE EQUIPMENT Equipment that is easily moved and can be carried or conveyed by hand. Portable equipment is usually hand-he
