1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 497C Protectors for Coaxial Communications Circuits STANDARD FOR SAFETYUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTE
2、D MATERIAL NOT AUTHORIZED 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 appro
3、val 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 of this pub
4、lication 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, including but not
5、 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 the inability
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8、ystem. FEBRUARY 10, 2017 UL 497C tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL FEBRUARY 10, 2017 UL 497C tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL
9、AUGUST 3, 2001 (Title Page Reprinted: February 10, 2017) 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 February 10, 2017. The mo
10、st recent designation of ANSI/UL 497C 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 Standard may be submitted to UL
11、 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. All of ULs Standards and a
12、ll copyrights, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2017 UNDERWRITERS LABORATORIES INC. ANSI/UL 497C-2004 (R2017)UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL JUNE 1
13、4, 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 measurement .8 2.3 Undated refe
14、rences .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 Arrester assemblies 15 8.3
15、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 Short-Circuit Test .27 17
16、 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 Test 38 27 Dielectric Volt
17、age-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 Elongation Tests .41 30 Air Oven
18、 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 exposure 43 33.4 Salt spray
19、 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 PROTECTORS FOR COAXIAL COMMU
20、NICATIONS 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 COPYRIGHTED MATERIAL NOT AUTHOR
21、IZED 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 covered by these requirem
22、ents, 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 subscriber premises agai
23、nst 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 secondary distribution wi
24、ring 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 Standard for Protectors for D
25、ata 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 for Protectors for Pair
26、ed-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 requirement that: a) Involves
27、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 AUTHORIZED FOR FURTHER REPR
28、ODUCTION 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 components are intended fo
29、r 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 approximate information
30、. 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 the latest edition of t
31、hat 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 spark gap, gas tube, soli
32、d-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 maximum current value equa
33、l 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 a thermo-resistance o
34、r 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 concentrations are dened in the
35、 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 positioning of the pr
36、oduct 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 environmental conditions which
37、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 AUTHORIZED FOR FURTHER REPR
38、ODUCTION 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 comprised of an overvoltage,
39、 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 produce a computed root-m
40、ean-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 applicable performance requ
41、irements 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) Provision for connect
42、ing 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 consist of an assembl
43、y 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-limiting device shall be
44、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 terminal of the coaxial pro
45、tector. 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 FOR FURTHER REPRODUCTI
46、ON 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 reduction of spacings, l
47、oosening 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
48、.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 enclosure. 5.2 Sheet metal 5.2.1 The thickness of sheet metal used for an enclosure of a protector shall not be less than the applicable va
49、lue specied in Table 5.1 or 5.2. Exception: Sheet metal of lesser thickness is not prohibited from being used when, considering the shape, size, and function of the enclosure, it is determined to provide equivalent mechanical strength. Table 5.1 Minimum thickness of sheet metal for electrical enclosures carbon steel or stainless steel Table 5.1 revised June 14, 2004 Without supporting frame a With supporting frame or equivalent reinforcing a Minimum thickness Maximum width, b Maximum leng
