1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 497C Protectors for Coaxial Communications CircuitsUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHO
2、RIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Protectors for Coaxial Communications Circuits, UL 497C Second Edition, Dated August 3, 2001 Summary of Topics This revision of ANSI/UL 497C is being issued to reaffirm ANSI approval of the Standard.
3、 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 on w
4、hich the changed requirement becomes effective. The revisions are substantially in accordance with Proposal(s) on this subject dated October 26, 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, electronic
5、, 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 liabl
6、e 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 of s
7、uch 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, d
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9、res, 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that have been revised and that have a future effective date are located after the Standard, and are preceded by a SUPERSEDED REQUIREMENTS no
10、tice. DECEMBER 21, 2012 UL 497C tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL DECEMBER 21, 2012 UL 497C tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL A
11、UGUST 3, 2001 (Title Page Reprinted: December 21, 2012) 1 UL 497C Standard for Protectors for Coaxial Communications Circuits First Edition March, 1998 Second Edition August 3, 2001 This ANSI/UL Standard for Safety consists of the Second Edition including revisions through December 21, 2012. The mos
12、t recent designation of ANSI/UL 497C as a Reaffirmed American National Standard (ANS) occurred on December 21, 2012. ANSI approval for a standard does not include the Cover Page, Transmittal Pages, Title Page, or effective date information. Comments or proposals for revisions on any part of the Stan
13、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 http:/. ULs Standards for Safety are copyrighted by UL. Neither a printed nor electronic copy of a Standard should be altered in any way.
14、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 497C-2004 (R2012)UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT
15、 PERMISSION FROM UL JUNE 14, 2004 PROTECTORS FOR COAXIAL COMMUNICATIONS CIRCUITS - UL 497C 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 7 2.1 Components .7 2.2 Units of meas
16、urement .8 2.3 Undated references .8 3 Glossary .8 CONSTRUCTION 4 General 9 5 Enclosures 10 5.1 General 10 5.2 Sheet metal 10 5.3 Nonmetallic .12 6 Protection Against Corrosion 13 6.1 General 13 6.2 Outdoor use 13 6.3 Grommets 13 7 Field-Wiring Connections .14 8 Components 15 8.1 General 15 8.2 Arre
17、ster assemblies 15 8.3 Electrical insulation material 15 9 Spacings 15 PERFORMANCE 10 General 18 11 I 2 t Limiting Test .22 12 Abnormal Sustained Current Test .23 13 Component Temperature Test 25 14 Breakdown Voltage Measurement Test 26 15 Impulse Sparkover Voltage Measurement Test .27 16 Limited Sh
18、ort-Circuit Test 27 17 High Current Ground Path Test .30 18 Cable Shield Fuse Test 31 19 Endurance Conditioning Test .31 20 Induced Low Current Test .32 21 Distortion Test 32 22 Flame Test .32 23 Impact Test (Polymeric Enclosures) .33 24 Jarring Test 34 25 Water Spray Test .34 26 Leakage Current Tes
19、t .38 27 Dielectric Voltage-Withstand Test .39 28 Ultraviolet Light and Water Exposure 40 JUNE 14, 2004 PROTECTORS FOR COAXIAL COMMUNICATIONS CIRCUITS - UL 497C 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 29 Tensile Strength and Elongat
20、ion Tests 41 30 Air Oven Aging Test 42 31 Ozone Exposure Test .42 32 Indoor Corrosion Test .42 32.1 General .42 32.2 Hydrogen sulde exposure 43 32.3 Sulfur dioxide-carbon dioxide 43 33 Outdoor Corrosion Test 43 33.1 General .43 33.2 Hydrogen sulde exposure 43 33.3 Sulfur dioxide-carbon dioxide expos
21、ure .43 33.4 Salt spray exposure 44 MARKINGS 34 General 44 INSTALLATION INSTRUCTIONS 35 General 45 AUGUST 3, 2001 PROTECTORS FOR COAXIAL COMMUNICATIONS CIRCUITS - UL 497C 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL AUGUST 3, 2001 PROTEC
22、TORS FOR COAXIAL COMMUNICATIONS CIRCUITS - UL 497C 5 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL This page intentionally left blank. JUNE 14, 2004 PROTECTORS FOR COAXIAL COMMUNICATIONS CIRCUITS - UL 497C 6UL COPYRIGHT
23、ED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover protectors for use on coaxial cable circuits to be used in accordance with the applicable requirements of the National Electrical Code, NFPA 70. 1.2 As cov
24、ered by these requirements, a coaxial cable circuit protector consists of single or multiple air gap arresters, gas tube arresters, or solid-state arresters, with or without fuses or other current-limiting devices. A circuit protector is intended to protect equipment, wiring, and personnel at the su
25、bscriber premises against the effects of excessive potentials and currents on the coaxial line caused by lightning, contacts with power conductors, power induction, or rises in ground potential. 1.3 This standard does not cover the following: a) Lightning protective devices for the protection of sec
26、ondary 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 re alarm signaling circuits that are covered by the Standar
27、d for Protectors for Data Communications and Fire-Alarm Circuits, UL 497B. e) Equipment covered by the Standard for Secondary Protectors for Communications Circuits, UL 497A. f) Equipment covered by the Standard for Transient Voltage Surge Suppressors, UL 1449. g) Equipment covered by the Standard f
28、or Protectors for Paired-Conductor Communications Circuits, UL 497. 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. 2.1.2 A component is not required to comply with a specic requirem
29、ent 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. JUNE 14, 2004 PROTECTORS FOR COAXIAL COMMUNICATIONS CIRCUITS - UL 497C 7UL COPYRIGHTED MATERIAL NOT AUTHO
30、RIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 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 comp
31、onents are intended for use only under limited conditions, such 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 a
32、pproximate information. 2.2.2 Unless otherwise indicated, all 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 t
33、he latest edition of that code or standard. 3 Glossary 3.1 For the purpose of this standard the following denitions apply. 3.2 ARRESTER An overvoltage component or assembly of components which permit current to ow through it when a designed voltage limit is reached. The arrester may consist of a spa
34、rk gap, gas tube, solid-state component or the equivalent, coupled with other hardware which serves to support, position, and align the current-carrying components that make up the arrester. 3.3 CURRENT-LIMITING This condition is achieved when the abnormal high current condition is reduced to a maxi
35、mum current value equal to the normal operating current of the circuit. 3.4 CURRENT-LIMITING DEVICE This device reacts to an abnormal high current condition to prevent overheating of the normal current path and/or circuit in series with the current-limiting device. These devices may take the form of
36、 a thermo-resistance or thermo-mechanical device. 3.5 INDOOR USE (CONTROLLED ENVIRONMENT) Installation of equipment in an area where the atmosphere is articially controlled. For the purpose of this standard, indoor ambient is limited to a temperature of 0 30C (32 86F). Limits for corrosion concentra
37、tions are dened in the test program. Rain does not occur. 3.6 MINIMUM CURRENT-LIMITING POINT The minimum abnormal current value which causes operation of the current-limiting device that reduces the current ow to a current-limited state. 3.7 NORMAL-USE POSITION (Position of Normal Use) A mounting or
38、 positioning of the product in an intended manner that is prescribed in the installation instructions of the manufacturer and conforms to the installation requirements of the National Electrical Code, ANSI/NFPA 70. 3.8 OUTDOOR USE (UNCONTROLLED ENVIRONMENT) An area subjected to the natural environme
39、ntal conditions which make-up the ambient and moisture extremes of this plant. For the purpose of consistency, the ambient and moisture extremes are dened in the various tests of this standard. AUGUST 3, 2001 PROTECTORS FOR COAXIAL COMMUNICATIONS CIRCUITS - UL 497C 8UL COPYRIGHTED MATERIAL NOT AUTHO
40、RIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 3.9 OUTSIDE PLANT (OSP) That part of the communications circuit extending from the subscriber premise protector to the main distribution frame of the public utility company providing the service. 3.10 PROTECTOR A device compri
41、sed of an overvoltage, overcurrent component, or both and is intended to prevent damage to a circuit or system when abnormally high voltage and/or current occur. 3.11 TRUE RMS Unit of electrical measurement by a meter capable of sampling, over time, the varying magnitude of a complex waveform to pro
42、duce a computed root-mean-square value equivalent to the same direct current value which produces the same heating effect. CONSTRUCTION 4 General 4.1 A coaxial cable circuit protector shall be constructed to withstand, without damage, its intended installation and use and shall comply with the appli
43、cable performance requirements specied in Sections 10 33. 4.2 A fuseless coaxial protector shall consist of an assembly comprising: a) An insulating base or grounded metallic base supporting an overvoltage arrester; b) Provision for connecting the center conductors of a coaxial cable circuit; and c)
44、 Provision for connecting at least one grounding conductor. An arrester shall be connected between the coaxial center conductor and ground. The connection or connections for the grounding conductor shall be conductively connected to a ground electrode or terminal. 4.3 A fused coaxial protector shall
45、 consist of an assembly comprising: a) An insulating base supporting an arrester; b) Provision for mounting a center conductor fuse; c) Provision for connecting the center conductors of a coaxial cable circuit; and d) Provision for connecting at least one grounding conductor. The fuse or current-lim
46、iting device shall be connected in series between each incoming center conductor of the outside plant (OSP) and the corresponding subscriber premises termination. The connection or connections for the grounding conductor or conductors shall be conductively connected to the ground electrodes or termi
47、nal of the coaxial protector. The overvoltage arrester shall be connected to the station termination end of the fuse or current-limiting device. A cover may be provided over the assembly. AUGUST 3, 2001 PROTECTORS FOR COAXIAL COMMUNICATIONS CIRCUITS - UL 497C 9UL COPYRIGHTED MATERIAL NOT AUTHORIZED
48、FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 4.4 A protector shall not have provision for adjustment of its components. 5 Enclosures 5.1 General 5.1.1 An enclosure for coaxial protectors shall have the strength and rigidity to resist total or partial collapse with attendant re
49、duction of spacings, loosening or displacement of parts, or other conditions that impair the operation of the product and increase the risk of re, electric shock, or injury to persons. 5.1.2 Enclosures for individual components, outer enclosures, and combinations of the two are considered in determining compliance with 5.1.1. 5.1.3 Protector enclosures shall have provision for mounting. 5.1.4 A protector intended for outdoor use shall be provided with a water-resistant cover or enclosur
