1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 452 Antenna Discharge UnitsUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPROD
2、UCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Antenna Discharge Units, UL 452 Seventh Edition, Dated November 2, 2006 Summary of Topics This revision of ANSI/UL 452 is being issued to reaffirm approval as an American National Standard. No changes in requirements are in
3、volved. The new and revised requirements are substantially in accordance with Proposal(s) on this subject dated November 6, 2015. 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 thi
4、s 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, including bu
5、t 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 the inab
6、ility 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 ULs Stan
7、dards 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 compu
8、ter system. DECEMBER 23, 2015 UL 452 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL DECEMBER 23, 2015 UL 452 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM
9、UL NOVEMBER 2, 2006 (Title Page Reprinted: December 23, 2015) 1 UL 452 Standard for Antenna Discharge Units First Edition December, 1953 Second Edition July, 1967 Third Edition April, 1972 Fourth Edition October, 1977 Fifth Edition November, 1987 Sixth Edition August, 1993 Seventh Edition November 2
10、, 2006 This ANSI/UL Standard for Safety consists of the Seventh Edition including revisions through December 23, 2015. The most recent designation of ANSI/UL 452 as a Reaffirmed American National Standard (ANS) occurred on December 23, 2015. ANSI approval for a standard does not include the Cover Pa
11、ge, Transmittal Pages, Title Page, or effective date information. Comments or proposals for 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 S
12、tandards 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 all copyrights, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2015 UNDERWRITERS LABOR
13、ATORIES INC. UL 452-2011 (R2015)UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL NOVEMBER 2, 2006 ANTENNA DISCHARGE UNITS - UL 452 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT P
14、ERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .4 2 References 4 CONSTRUCTION 3 General 4 4 Enclosure 4 5 Protection Against Corrosion .4 6 Insulating Material 5 7 Current-Carrying Parts 5 8 Terminals 5 9 Fuses .6 PERFORMANCE 10 Internal Resistance .6 11 Discharge Test .6 12 Installation Test 6 MAR
15、KING 13 Details 7 NOVEMBER 2, 2006 ANTENNA DISCHARGE UNITS - UL 452 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover antenna-discharge units for radio and television receiving equipment and a
16、mateur radio-transmitting and -receiving equipment, to be employed in accordance with the National Electrical Code, NFPA 70. 1.2 An antenna-discharge unit hereinafter referred to as a discharge unit as covered by these requirements consists of a gap, a xed resistance or other discharge element, or a
17、 combination of such features, connected between each antenna lead-in terminal and a grounding terminal. 2 References 2.1 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. CONST
18、RUCTION 3 General 3.1 A gap-type discharge unit shall have a xed gap that is constructed so that it cannot be readily altered or adjusted in the eld. 3.2 A discharge unit of other than the gap type shall be constructed so that the resistance between the antenna and ground terminals cannot be readily
19、 altered or adjusted in the eld. 4 Enclosure 4.1 The discharge chamber of a discharge unit shall be dust tight and, if the discharge unit is intended for outdoor use, the discharge chamber shall be watertight. 4.2 A discharge unit shall have means for mounting. 5 Protection Against Corrosion 5.1 Iro
20、n and steel parts shall be protected against corrosion by enameling, galvanizing, plating, or an equivalent means. NOVEMBER 2, 2006 ANTENNA DISCHARGE UNITS - UL 452 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 6 Insulating Material 6.1 A
21、 base or body for the mounting or enclosing of uninsulated live parts shall be of moisture-resistant insulating material. 6.2 Material for the mounting of uninsulated live parts shall be porcelain, phenolic composition, or other material acceptable for the application. Fiber and rubber are not accep
22、table. A material other than the above shall be appropriately investigated. 7 Current-Carrying Parts 7.1 A current-carrying part shall be brass, phosphor-bronze, carbon, or other corrosion-resistant material. Exception: A grounding strap may be stainless steel, or sheet steel if it is protected agai
23、nst corrosion by a zinc or an equivalent metallic coating. See the exception to 8.1, and 12.1. 8 Terminals 8.1 A discharge unit for receiving equipment shall be provided with terminals for the connection of: a) The antenna, and b) 17 AWG or larger grounding leads. Exception: A discharge unit intende
24、d for indoor use only may be provided with a grounding strap for direct connection to a metal water-pipe ground in place of a terminal for a grounding lead. 8.2 A discharge unit for transmitting equipment shall be provided with terminals for the connection of: a) The antenna, and b) 10 AWG or larger
25、 grounding leads. 8.3 Terminals employing means other than wire-binding screws or stud terminals with nuts may be employed for the connection of the antenna leads if the construction is shown by investigation to be acceptable. The investigation is to include tests to determine whether contact is mad
26、e with the conductors of the antenna leads. 8.4 A wiring terminal shall be prevented from turning, and shall not employ a setscrew form of contact. 8.5 A wire-binding screw shall be provided with upturned lugs or the equivalent, and shall thread into metal. 8.6 A terminal plate tapped for a wire-bin
27、ding screw shall be of metal not less than 0.030-inch thick. There shall be two or more full threads in the metal. The metal may be extruded at the tapped hole to provide at least two full threads. MARCH 23, 2007 ANTENNA DISCHARGE UNITS - UL 452 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER RE
28、PRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 8.7 A grounding terminal shall be provided with upturned lugs, a cupped washer, or the equivalent capable of retaining a grounding conductor of the size specied in 8.1 and 8.2 under the head of a screw or washer. 9 Fuses 9.1 A fuse employed in a
29、discharge unit shall not be connected in the circuit between an antenna terminal and the grounding terminal. PERFORMANCE 10 Internal Resistance 10.1 Each of six samples of a discharge unit shall have an internal resistance of not less than 75,000 ohms between each antenna terminal and the grounding
30、terminal. 10.2 To determine whether a discharge unit complies with the requirement in 10.1, a direct-current potential of 6 volts is to be applied between each antenna terminal and the grounding terminal, and the current ow is to be measured by a microammeter. 11 Discharge Test 11.1 Each of six samp
31、les of a discharge unit shall discharge when subjected to ve successive applications of a direct-current potential of 500 volts from a 2-microfarad capacitor. After the fth application of the test voltage, the internal resistance between each antenna terminal and the grounding terminal shall not be
32、less than 75,000 ohms, and the antenna-ground circuit of a discharge unit employing a resistor shall not open. 11.2 A discharge unit of the gap type shall comply with the requirement in 11.1 and shall be investigated to determine that successive discharges will not result in an increased gap. 12 Ins
33、tallation Test 12.1 A discharge unit employing a grounding strap shall withstand without damage, a tightening torque of 150 pound-inches applied to each clamping bolt or screw when assembled on the grounding electrode with which it is intended to be used. Exception: A torque of 50 pound-inches is to
34、 be applied to a clamping screw intended to be tightened using a screwdriver only. 12.2 With reference to the requirement in 12.1, two samples of a discharge unit are to be tested, except that if a unit is designed for use with a range of electrode sizes, four samples are to be tested two samples wi
35、th the largest size electrode and two with the smallest size. NOVEMBER 2, 2006 ANTENNA DISCHARGE UNITS - UL 452 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL MARKING 13 Details 13.1 A discharge unit shall be plainly marked, where it will
36、be visible after installation, with the manufacturers name, trademark, or other descriptive marking by which the organization responsible for the product may be identied, and a distinctive catalog number or the equivalent. 13.2 A discharge unit intended for indoor use only shall be permanently marke
37、d For Indoor Use Only, or the equivalent. 13.3 A discharge unit shall not be marked Lightning Arrester, but may be marked Antenna-Discharge Unit, Discharge Unit, or the equivalent. 13.4 The terminals of a discharge unit shall be plainly marked Antenna and Ground, or with equivalent symbols or abbrev
38、iations, to indicate the proper connections. Exception: The markings may be omitted if the proper connection are obvious to the user. 13.5 A strap provided for connecting a discharge unit to a metal water-pipe ground shall be marked with the pipe size, or range of sizes, with which it is intended to
39、 be used. 13.6 If a manufacturer produces or assembles an antenna discharge unit at more than one factory, each nished device shall have a distinctive marking, which may be in code, by which it may be identied as the product of a particular factory. NOVEMBER 2, 2006 ANTENNA DISCHARGE UNITS - UL 452 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL NOVEMBER 2, 2006 ANTENNA DISCHARGE UNITS - UL 452 8 No Text on This Page
