ITU-T K 21-2015 Resistibility of telecommunication equipment installed in customer premises to overvoltages and overcurrents (Study Group 5)《在电信中心的过电压和过电流的抗电讯设备安装(研究组5)》.pdf

1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T K.21 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (04/2015) SERIES K: PROTECTION AGAINST INTERFERENCE Resistibility of telecommunication equipment installed in customer premises to overvoltages and overcurrents Recommend

2、ation ITU-T K.21 Rec. ITU-T K.21 (04/2015) i Recommendation ITU-T K.21 Resistibility of telecommunication equipment installed in customer premises to overvoltages and overcurrents Summary Recommendation ITU-T K.21 specifies resistibility requirements and test procedures for telecommunication equipme

3、nt that is attached to or installed within a customers premises. Overvoltages or overcurrents covered by this Recommendation include surges due to lightning on or near the line plant, short-term induction from adjacent a.c. power lines or railway systems, earth potential rise due to power faults, di

4、rect contact between telecommunication lines and power lines and electrostatic discharges. The sources for overvoltages in internal lines are mainly inductive coupling caused by lightning currents being conducted in nearby lightning strokes or lightning currents being conducted in nearby conductors.

5、 Major changes compared with the 2008 version of this Recommendation include: updated references; added information on which universal serial bus (USB) ports should be tested; added information on when to add protection to untested ports; added test requirements for external coaxial cable ports; add

6、ed test requirements for multiple conductor internal unshielded cable ports. Major changes compared with the 2011 version of this Recommendation include: added test requirements for unshielded twisted pair (UTP) Ethernet; added test requirements for shielded twisted pair (STP Ethernet; added test re

7、quirements for power over Ethernet (PoE); added STP shield testing. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T K.21 1988-11-25 11.1002/1000/1390 2.0 ITU-T K.21 1996-10-18 5 11.1002/1000/3881 3.0 ITU-T K.21 2000-10-06 5 11.1002/1000/5153 4.0 ITU-T K.21 2003-07-29 5 11.10

8、02/1000/6493 5.0 ITU-T K.21 2008-04-13 5 11.1002/1000/9401 6.0 ITU-T K.21 2011-11-13 5 11.1002/1000/11421 7.0 ITU-T K.21 2015-04-22 5 11.1002/1000/12404 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations uniq

9、ue ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T K.21 (04/2015) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunicat

10、ion Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (

11、WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fal

12、l within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Re

13、commendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language

14、such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recomm

15、endation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of appr

16、oval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB

17、patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2015 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T K.21 (04/2015) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 1 3.1 Te

18、rms defined elsewhere: . 1 3.2 Terms defined in this Recommendation . 1 4 Abbreviations and acronyms 2 5 Conventions 2 6 Tests 2 Bibliography. 27 Rec. ITU-T K.21 (04/2015) 1 Recommendation ITU-T K.21 Resistibility of telecommunication equipment installed in customer premises to overvoltages and over

19、currents 1 Scope This Recommendation specifies resistibility requirements and test procedures for telecommunication equipment which is attached to or installed within a customers premises. The requirements of this Recommendation assume that earthing and bonding is in accordance with ITU-T K.66. The

20、types of equipment covered by this Recommendation include all types of telecommunication equipment, e.g., modems, telephones, routers, implementations of digital subscriber lines and personal computers. NOTE Associated equipment containing ports with a low surge impedance to earth connected by short

21、 cables, e.g., printers using universal serial bus (USB) cables, may be susceptible to damage due to circulating earth currents. Refer to ITU-T K.66 and b-ITU-T K.85 for methods of protection. This Recommendation applies to both external and internal ports. ITU-T K.44, covering basic test methods an

22、d test circuits, is an integral part of this Recommendation and should be read in conjunction with ITU-T K.11 and ITU-T K.39. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation.

23、At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed

24、 below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T K.11 Recommendation ITU-T K.11 (2009), Principles of protection against overvo

25、ltages and overcurrents. ITU-T K.39 Recommendation ITU-T K.39 (1996), Risk assessment of damages to telecommunication sites due to lightning discharges. ITU-T K.44 Recommendation ITU-T K.44 (2012), Resistibility tests for telecommunication equipment exposed to overvoltages and overcurrents Basic Rec

26、ommendation. ITU-T K.66 Recommendation ITU-T K.66 (2011), Protection of customer premises from overvoltages. IEC 61000-4-2 IEC 61000-4-2 (2008), Electromagnetic compatibility (EMC) Part 4-2: Testing and measurement techniques Electrostatic discharge immunity test. 3 Definitions 3.1 Terms defined els

27、ewhere: This Recommendation uses terms defined in ITU-T K.44. 3.2 Terms defined in this Recommendation None. 2 Rec. ITU-T K.21 (04/2015) 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: CWG Combination Wave Generator ESD Electrostatic Discharge PoE Powe

28、r over Ethernet STP Shielded Twisted Pair USB Universal Serial Bus UTP Unshielded Twisted Pair 5 Conventions Conventions and symbols used in this Recommendation are defined in ITU-T K.44. 6 Tests A summary of the tests applicable to equipment installed in a customers premises is given in Table 1. Th

29、e numbers given in the “Port type“ columns, e.g., 2.2.1a, refer to the “Test no.“ of Tables 2 to 5. The words “under study“ mean that ITU-T is still studying this test. The test conditions applicable to the four ports: symmetric, coaxial, dedicated power feed and mains power are given in Tables 2 to

30、 5. The test conditions for electrostatic discharge (ESD) are given in Table 6. The test conditions for internal cable ports are given in Table 7. For information on the headings and terms used in the tables, refer to clause 10 of ITU-T K.44. Refer to clause 5.2 of ITU-T K.44 on selecting the enhanc

31、ed resistibility requirement. NOTE 1 The port to external port test for the basic test level does not apply when the equipment is designed to always be used with a connection to earth. NOTE 2 The external port test applies to ports used to connect externally-attached equipment to equipment installed

32、 within the same building. The mains power contact test does not apply in this situation. Where the equipment, external to the building, is installed in the “inherently protected“ area shown in Figure 3 of b-ITU-T K.71, the internal port test can be applied. NOTE 3 The power induction test does not

33、apply to ports used to connect to antennas installed under the scope of b-ITU-T K.71. NOTE 4 The internal port tests in Table 7 apply to ports connected by short cables, e.g., universal serial bus (USB) and printer cables. Table 7 does not apply to ports connected infrequently, e.g., for maintenance

34、 ports. Table 1a Applicable tests for external ports Test type No. of pairs simultaneously tested Test connections Primary protection Port type Symmetric port Co-axial port Dedicated power feed port Mains power port Lightning/ voltage Single Transverse/ differential No 2.1.1a 3.1.1 4.1.1a 5.1.1a Por

35、t to earth No 2.1.1b n.a. 4.1.1b 5.1.1b Port to external port No 2.1.1c n.a. 4.1.1c 5.1.1c Coordination/Transverse/ differential Yes 2.1.2a 3.1.2 4.1.2a 5.1.2a Rec. ITU-T K.21 (04/2015) 3 Table 1a Applicable tests for external ports Test type No. of pairs simultaneously tested Test connections Prima

36、ry protection Port type Symmetric port Co-axial port Dedicated power feed port Mains power port Coordination/Port to earth Yes 2.1.2b n.a. 4.1.2b 5.1.2b Coordination/Port to external port Yes 2.1.2c n.a. 4.1.2c 5.1.2c Multiple Port to earth No 2.1.3a n.a. n.a. n.a. Port to external port No 2.1.3b n.

37、a. n.a. n.a. Port to earth Yes 2.1.4a n.a. n.a. n.a. Port to external port Yes 2.1.4b n.a. n.a. n.a. Unshielded twisted pair (UTP) Ethernet Port to earth No n.a. n.a. n.a. n.a. Transverse No 2.1.7 n.a. n.a. n.a. Voltage impulse a test No 2.1.10 n.a. n.a. n.a. Power over Ethernet (PoE) No 2.1.9 n.a.

38、n.a. n.a. STP Shield Shield to earth No 2.1.11 2.1.11 n.a. n.a. Port to earth No 2.1.8 2.1.8 n.a. n.a. Lightning current Single Port to earth No 2.1.5a n.a. 4.1.5a n.a. Port to external port No 2.1.5b n.a. 4.1.5b n.a. Multiple Port to earth No 2.1.6a, 2.1.10 n.a. n.a. n.a. Port to external port No 2

39、.1.6b n.a. n.a. n.a. Differential n.a. n.a. 3.1.3 n.a. n.a. Shield to earth n.a. n.a. 3.1.4 n.a. n.a. Shield to external port n.a. n.a. 3.1.5 n.a. n.a. Insulation Multiple Port to earth n.a. 2.1.10, 7.6 n.a. n.a. n.a. 4 Rec. ITU-T K.21 (04/2015) Table 1a Applicable tests for external ports Test type

40、 No. of pairs simultaneously tested Test connections Primary protection Port type Symmetric port Co-axial port Dedicated power feed port Mains power port Power induction and earth potential rise Single Transverse No 2.2.1a Understudy 4.2.1a n.a Port to earth No 2.2.1b n.a. 4.2.1b 5.2.1 under study P

41、ort to external port No 2.2.1c n.a. 4.2.1c 5.2.1 under study Coordination Transverse Yes 2.2.2a Understudy 4.2.2a n.a. Coordination Port to earth Yes 2.2.2b n.a. 4.2.2b n.a. Coordination Port to external port Yes 2.2.2c n.a. 4.2.2c n.a. Neutral potential rise Single Port to earth No n.a. n.a. n.a. 5

42、.2.2a Port to external port No n.a. n.a. n.a. 5.2.2b Mains power contact Single Transverse No 2.3.1a n.a. 4.3.1a n.a. Port to earth No 2.3.1b n.a. 4.3.1b n.a. Port to external port No 2.3.1c n.a. 4.3.1c n.a. Table 1b Applicable tests for ports connected to internal cabling Test type Primary protecti

43、on Unshielded cable Shielded cable PoE Floating d.c. power interface Earthed d.c. power interface Lightning No 7.1, 7.6, 7.2, 7.3, 7.4, 7.7 7.5 7.7 7.8 5 Rec. ITU-T K.21 (04/2015) Table 2a Lightning test conditions for ports connected to external symmetric pair cables Test no. Test description Test

44、circuit and waveform (see figures in Annex A of ITU-T K.44) Basic test levels (also see clause 7 of ITU-T K.44) Enhanced test levels (also see clauses 5 and 7 of ITU-T K.44) Number of tests Primary protection ITU-T K.44, clause 8 Acceptance criteria ITU-T K.44, clause 9 Comments 2.1.1a Single pair,

45、lightning, inherent, transverse A.3-1 and A.6.1-1 (a and b) 10/700 s Uc(max) = 1.5 kV R = 25 Uc(max) = 1.5 kV R = 25 alternating 5 surges (60 seconds between successive surges) None A Test 2.1.1 does not apply when the equipment is designed to always be used with primary protection and the operator

46、agrees. If this test is not performed, the appropriate test from Table 7 applies. If the inherent protection of the port under test contains surge protective devices (SPDs) that are connected to earth, a Uc(max) of 1.5 kV shall be used instead of 6 kV. If the equipment has an insulated case, the 6 k

47、V test is applied with the equipment wrapped in conductive foil and the foil is connected to the generator return. When the equipment contains high current-carrying components which eliminate the need for primary protection, this test does not apply. (lower voltage level testing also required for ea

48、ch test see ITU-T K.44, clause 7.3) 2.1.1b Single pair, lightning, inherent, port to earth A.3-1 and A.6.1-2 10/700 s Uc(max) = 1.5 kV R = 25 Uc(max) = 6 kV See comments R = 25 2.1.1c Single pair, lightning, inherent, port to external port A.3-1 and A.6.1-3 10/700 s Uc(max) = 1.5 kV R = 25 Uc(max) =

49、 6 kV See comments R = 25 6 Rec. ITU-T K.21 (04/2015) Table 2a Lightning test conditions for ports connected to external symmetric pair cables Test no. Test description Test circuit and waveform (see figures in Annex A of ITU-T K.44) Basic test levels (also see clause 7 of ITU-T K.44) Enhanced test levels (also see clauses 5 and 7 of ITU-T K.44) Number of tests Primary protection ITU-T K.44, clause 8 Acceptance criteria ITU-T K.44, clause 9