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.51 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (06/2016) SERIES K: PROTECTION AGAINST INTERFERENCE Safety criteria for telecommunication equipment Recommendation ITU-T K.51 Rec. ITU-T K.51 (06/2016) i Recommendation I
2、TU-T K.51 Safety criteria for telecommunication equipment Summary Recommendation ITU-T K.51 provides guidance on safety criteria for telecommunication network infrastructure equipment. It specifies requirements intended to reduce risks of fire, electric shock or injury for specified classes of perso
3、ns who may come into contact with the equipment. This Recommendation refers to the IEC safety standards IEC 60950-1 and IEC 62368-1 and provides additional requirements when these are not covered by the IEC standards. Equipment complying with the relevant requirements in this Recommendation is consi
4、dered suitable for use in a telecommunication network. However, this Recommendation does not include requirements for performance or functional characteristics of equipment. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T K.51 2000-02-25 5 11.1002/1000/4914 2.0 ITU-T K.51 20
5、09-07-14 5 11.1002/1000/10016 3.0 ITU-T K.51 2016-06-29 5 11.1002/1000/12872 Keywords Remote power feeding, safety, telecommunication equipment. * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For
6、 example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T K.51 (06/2016) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standa
7、rdization 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 (WTSA), whi
8、ch 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 fall within I
9、TU-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 Recommendati
10、on 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 such as “m
11、ust“ 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 Recommendation m
12、ay 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 approval of th
13、is 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 patent dat
14、abase at http:/www.itu.int/ITU-T/ipr/. ITU 2016 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.51 (06/2016) iii Table of Contents Page 1 Scope . 1 1.1 Equipment covered by this Recommendation 1 1.
15、2 Additional requirements . 1 2 References . 1 3 Definitions 2 3.1 Terms defined elsewhere 2 3.2 Terms defined in this Recommendation . 4 4 Abbreviations and acronyms 6 5 Safety criteria for telecommunication network infrastructure equipment 6 5.1 General requirements 6 5.2 Special requirements 6 Ap
16、pendix I Cross-reference between Recommendation ITU-T K.51, IEC 60950-1 and IEC 62368-1 10 Bibliography. 12 iv Rec. ITU-T K.51 (06/2016) Introduction This Recommendation provides guidance on safety criteria for telecommunication network infrastructure equipment. The requirements of the original 2009
17、 version of this Recommendation where developed in cooperation with IEC TC108 based on IEC 60950-1. This updated version of this Recommendation incorporates the new definitions and requirements of IEC 62368-1, a new hazard-based safety standard created by IEC TC 108. This Recommendation should be re
18、ad together with IEC 60950-1 and IEC 62368-1 for best comprehension. Rec. ITU-T K.51 (06/2016) 1 Recommendation ITU-T K.51 Safety criteria for telecommunication equipment 1 Scope 1.1 Equipment covered by this Recommendation This Recommendation is applicable to mains-powered, battery-powered or remot
19、ely-powered telecommunication network infrastructure equipment. This Recommendation specifies requirements intended to reduce risks of fire, electric shock, mechanical hazards or injury for the designated classes of user, ordinary person, instructed person, service person and skilled person. This Re
20、commendation is intended to reduce such risks with respect to installed equipment, whether it consists of a system of interconnected units or independent units, subject to installing, operating and maintaining the equipment in the manner prescribed by the manufacturer. Equipment complying with the r
21、elevant requirements in this Recommendation is considered suitable for use in a telecommunication network. However, this Recommendation does not include requirements for performance or functional characteristics of equipment. 1.2 Additional requirements Requirements additional to those specified in
22、this Recommendation may be necessary for: equipment intended for operation in special environments, for example: extremes of temperature; excessive dust, moisture or vibration; flammable gases; and corrosive or explosive atmospheres; equipment intended to be used in vehicles, on board ships or aircr
23、aft, in tropical countries, or at altitudes greater than 2000 m; equipment intended for use where ingress of water is possible. NOTE Attention is drawn to the fact that authorities of some countries impose additional requirements. 2 References The following ITU-T Recommendations and other references
24、 contain provisions which, through reference in this text, constitute provisions of this Recommendation. 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 investiga
25、te the possibility of applying the most recent edition of the Recommendations and other references listed 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
26、of a Recommendation. ITU-T K.50 Recommendation ITU-T K.50 (2000), Safe limits of operating voltages and currents for telecommunication systems powered over the network. IEC 60950-1 IEC 60950-1 (2005), Information technology equipment Safety Part 1: General requirements. IEC 60950-21 IEC 60950-21 (20
27、02), Information technology equipment Safety Part 21: Remote power feeding. IEC 62368-1 IEC 62368-1 (2014), Audio/video, information and communication technology equipment Part 1: Safety requirements. 2 Rec. ITU-T K.51 (06/2016) NOTE 1 This Recommendation refers to IEC 60950-1, but the related conce
28、pts or requirements of IEC 60950 are still applicable in countries where IEC 60950 is still used. NOTE 2 IEC 60950-21 is a companion standard to IEC 60950-1 that covers remote power feeding. IEC TC 108 is developing a corresponding companion standard to IEC 62368-1 with a designation of IEC 62368-3.
29、 3 Definitions In this Recommendation, definitions introduced by ITU-T K.50, IEC 60950-1, IEC 62368-1 and IEC 60950-21 are used to maintain conformity. For convenience, they are reproduced here. Other definitions, currently under study in IEC, have been added. NOTE The definition of circuits in IEC
30、60950-1 is limited to circuits internal to equipment. In IEC 62368-1 the definition of circuits is limited to circuits external to equipment, which are normally considered to be a telecommunication network. For this Recommendation, the definition of circuits is extended to include network cable cond
31、uctors that carry the same voltages/currents. 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 basic insulation IEC 60950-1: Insulation to provide basic protection against electric shock. NOTE IEC 62368-1 refers to “basic safeguard“ rather than “basic
32、 protection“ and notes “This concept does not apply to insulation used exclusively for functional purposes“. 3.1.2 double insulation IEC 60950-1 IEC 62368-1: Insulation comprising both basic insulation and supplementary insulation. 3.1.3 ELV circuit IEC 60950-1: Secondary circuit with voltages betwe
33、en any two conductors of the circuit, and between any one such conductor and earth (see clause 1.4.9), not exceeding 42,4 V peak, or 60 V d.c., under normal operating conditions, which is separated from hazardous voltage by basic insulation, and which neither meets all of the requirements for an SEL
34、V circuit nor meets all of the requirements for a limited current circuit. 3.1.4 external circuit IEC 62368-1: Electrical circuit that is external to the equipment and is not mains. NOTE An external circuit is classified as operating at ES1, ES2 or ES3, and PS1, PS2, or PS3 levels. 3.1.5 functional
35、insulation IEC 62368-1: Insulation between conductive parts which is necessary only for the proper functioning of the equipment. NOTE IEC 60950-1 adds the informative note “functional insulation by definition does not protect against electric shock. It may, however, reduce the likelihood of ignition
36、 and fire“. 3.1.6 hazardous voltage IEC 60950-1: Voltage exceeding 42,4 V peak, or 60 V d.c., existing in a circuit that does not meet the requirements for either a limited current circuit or a TNV circuit. NOTE The corresponding IEC 62368-1 requirement would be voltages exceeding ES1. 3.1.7 instruc
37、ted person IEC 62368-1: Person instructed or supervised by a skilled person as to energy sources and who can responsibly use equipment safeguards and precautionary safeguards with respect to those energy sources. NOTE 1 Supervised, as used in the definition, means having the direction and oversight
38、of the performance of others. NOTE 2 In the context of this Recommendation, the term instructed person is synonymous with user IEC 60950-1. Rec. ITU-T K.51 (06/2016) 3 3.1.8 limited current circuit IEC 60950-1: Circuit that is so designed and protected that, under both normal operating conditions an
39、d single fault conditions, the current that can be drawn is not hazardous. NOTE 1 Simulated faults and abnormal conditions are defined in IEC 60950-1 clause 1.4.14. NOTE 2 The limit value of d.c. is defined as 2 mA d.c. through a 2 k resistor connected between any two parts of a limited current circ
40、uit, or between any such part and earth in clause 2.4 of IEC 60950-1. 3.1.9 ordinary person IEC 62368-1: Person who is neither a skilled person nor an instructed person. NOTE In the context of this Recommendation, the term ordinary person is synonymous with user IEC 60950-1. 3.1.10 primary circuit I
41、EC 60950-1: Circuit that is directly connected to the AC mains supply. 3.1.11 prospective touch voltage IEC 62368-1: Voltage between simultaneously accessible conductive parts when those conductive parts are not being touched. 3.1.12 public network interface b-ISO/IEC 11801: A point of demarcation b
42、etween public and private network. In many cases the public network interface is the point of connection between the network providers facilities and the customer premises cabling. 3.1.13 reinforced insulation IEC 62368-1: Single insulation system that provides a degree of protection against electri
43、c shock equivalent to double insulation. NOTE IEC 60950-1 adds the informative note “The term “insulation system“ does not imply that the insulation has to be in one homogeneous piece. It may comprise several layers that cannot be tested as basic insulation and supplementary insulation“. 3.1.14 RFT-
44、C circuit ITU-T K.50: A current limited RFT circuit. NOTE The detailed characteristics of an RFT-C circuit are described in ITU-T K.50. 3.1.15 RFT-V circuit: A voltage limited RFT circuit. NOTE The detailed characteristics of an RFT-V circuit are described in ITU-T K.50. 3.1.16 secondary circuit IEC
45、 60950-1: Circuit that has no direct connection to a primary circuit and derives its power from a transformer, converter or equivalent isolation device, or from a battery. NOTE 1 In the context of this Recommendation, the definition of circuits is extended to include network cable conductors that ca
46、rry the same voltages/currents. NOTE 2 IEC 62368-1 does not define the term secondary circuit, but refers to it as circuit within the equipment not connected to an a.c. mains. 3.1.17 SELV circuit IEC 60950-1: Secondary circuit which is so designed and protected that, under normal and single fault co
47、nditions, its voltages do not exceed a safe value. NOTE 1 Simulated faults and abnormal conditions are defined in IEC 60950, clause 1.4.14. NOTE 2 Maximum safe d.c. voltages are defined as 60 V d.c., under normal operating conditions and 120 V d.c. for less than 200 ms, under single fault conditions
48、 in IEC 60950, clause 2.2. 3.1.18 service personnel IEC 60950-1: Persons having appropriate technical training and experience necessary to be aware of hazards to which they are exposed in performing a task and of measures to minimize the danger to themselves or other persons. NOTE In the context of
49、this Recommendation, service personnel must be authorized by the network operator. 3.1.19 skilled person IEC 62368-1: Person with relevant education or experience to enable him or her to identify hazards and to take appropriate actions to reduce the risks of injury to themselves and others. NOTE In the context of this Recommendation, the term skilled personnel is synonymous with service personnel IEC 60950-1.
