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.117 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (12/2016) SERIES K: PROTECTION AGAINST INTERFERENCE Primary protector parameters for the surge protection of equipment Ethernet ports Recommendation ITU-T K.117 Rec. ITU
2、-T K.117 (12/2016) i Recommendation ITU-T K.117 Primary protector parameters for the surge protection of equipment Ethernet ports Summary Recommendation ITU-T K.117 specifies the common-mode, differential mode and common mode to differential mode conversion surge parameter and test circuit requireme
3、nts of an Ethernet port primary protector. The preferred surge generator voltage levels are 2.5 kV, 6 kV and 12 kV, but the test circuits can be used for any surge voltage environmental. Power over Ethernet (PoE) feed requirements are also given. Ethernet signal performance parameters are not covere
4、d and standards such as b-IEC 60603-7-7 may be used for this purpose. This Recommendation should be used for the harmonization of existing or future specifications issued by Ethernet surge protective device (SPD) manufacturers, telecommunication equipment manufacturers, administrations or network op
5、erators. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T K.117 2016-12-14 5 11.1002/1000/13133 Keywords Ethernet, in-line SPD, insulation resistance, overvoltage protector, Power over Ethernet (PoE), primary protector, surge protective device (SPD). * To access the Recommend
6、ation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T K.117 (12/2016) FOREWORD The International Telecommunication Union (ITU) is the United Nations special
7、ized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication 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 wit
8、h a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (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 Reco
9、mmendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall 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 c
10、onciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recomm
11、endation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language 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 par
12、ty. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Ri
13、ghts, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implement
14、ers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2017 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written pe
15、rmission of ITU. Rec. ITU-T K.117 (12/2016) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 1 3.1 Terms defined elsewhere 1 3.2 Terms defined in this Recommendation . 3 4 Abbreviations and acronyms 3 5 Conventions 3 5.1 Connections 3 5.2 Protective function 4 6 Electrical param
16、eters 4 6.1 Common-mode surge . 5 6.2 Differential-mode surge 6 6.3 Common-mode to differential-mode surge conversion 9 6.4 Surge durability (optional) . 11 6.5 Cable screen terminal . 11 7 DC tests . 12 7.1 Insulation resistance . 12 7.2 DC voltage drop . 13 8 Identification . 14 8.1 Marking 14 8.2
17、 Documentation . 14 9 Ordering information 14 Bibliography. 15 Rec. ITU-T K.117 (12/2016) 1 Recommendation ITU-T K.117 Primary protector parameters for the surge protection of equipment Ethernet ports 1 Scope This Recommendation applies to surge protective devices (SPDs) to be used for Ethernet prim
18、ary protection in surge voltage environments with a peak value of 2.5 kV and above. It covers the following device parameters: a) electrical surge b) electrical d.c. c) identification and marking. This Recommendation does not deal with: a) mountings for SPDs and their effect on characteristics; b) m
19、echanical dimensions; c) quality assurance requirements; d) units containing current limiters; e) signal performance parameters, standards such as b-IEC 60603-7-7 may be used for this purpose; f) diagnostic properties such as indicators and status monitor outputs. 2 References The following ITU-T Re
20、commendations and other references 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
21、 therefore encouraged to investigate 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
22、 stand-alone document, the status of a Recommendation. ITU-T K.44 Recommendation ITU-T K.44 (2016), Resistibility tests for telecommunication equipment exposed to overvoltages and overcurrents Basic Recommendation. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following term
23、s defined elsewhere: 3.1.1 common-mode conversion b-ITU-T K.96: Process by which a differential mode electrical signal is produced in response to a common mode electrical signal. NOTE This definition is based on the definition provided in b-IEC 60050-161. 3.1.2 common-mode surge b-ITU-T K.96: Surge
24、appearing equally on all conductors of a group at a given location. NOTE 1 The reference point for common-mode surge voltage measurement can be a chassis terminal, or a local earth/ground point. NOTE 2 Also known as longitudinal surge or asymmetrical surge. 2 Rec. ITU-T K.117 (12/2016) 3.1.3 connect
25、or b-IEC 14776-153: Electro-mechanical components consisting of a receptacle and a plug that provide a separable interface between two transmission segments. 3.1.4 differential-mode surge b-ITU-T K.96: Surge occurring between any two conductors or two groups of conductors at a given location. NOTE 1
26、 The surge source maybe be floating, without a reference point or connected to reference point, such as a chassis terminal, or a local earth/ground point. NOTE 2 Also known as metallic surge or transverse surge or symmetrical surge or normal surge. 3.1.5 hard-wired b-IEC 60601-2-1: Term used where t
27、he features of a system can be modified only by physically removing and re-routing wires. 3.1.6 insulation b-IEC 60664-2-1: That part of an electrotechnical product which separates the conducting parts at different electrical potentials. 3.1.7 isolating transformer b-IEC 60065: Transformer with prot
28、ective separation between the input and output windings. NOTE Isolating transformers can be divided into three groups; mains, switched mode and signal (e.g., Ethernet data). 3.1.8 impulse limiting voltage, VP b-ITU-T K.28: Highest value of voltage across the terminals of the SPD during the applicati
29、on of a specified impulse. NOTE Also called voltage protection level or measured limiting voltage. 3.1.9 in-line SPD b-ITU-T K.28: A two-port SPD connected in series with the service feed. 3.1.10 insulation resistance (effective) b-ITU-T K.28: Quotient of the voltage applied to a designated terminal
30、 pair, VIR, by the current, IIR, drawn from the applied voltage. 3.1.11 impulse generator charge voltage, VC b-ITU-T K.82: Value of impulse generator charging voltage. 3.1.12 impulse withstand voltage b-IEC 60664-2-1: Highest peak value of impulse voltage of prescribed form and polarity applied to a
31、 circuit or equipment, which does not cause degradation or result in breakdown or flashover. 3.1.13 let-through current b-ITU-T K.28: In-line SPD peak short-circuit output current when a specified impulse is applied to the SPD input. 3.1.14 overvoltage b-IEC 60664-2-1: Any voltage having a peak valu
32、e exceeding the corresponding peak value of maximum steady-state voltage at normal operating conditions. 3.1.15 parameter b-IEC 61643-341: Device descriptor that is measurable or quantifiable, such as a characteristic or rating. 3.1.16 port b-IEC 60050-131: Access to a device or network where electr
33、omagnetic energy or signals may be supplied or received or where the device or network variables may be observed or measured. NOTE An example of a port is a terminal pair. 3.1.17 primary protection ITU-T K.44: Means by which the majority of the surge stress is prevented from propagating beyond a des
34、ignated location (preferably the building entrance point). 3.1.18 rated peak impulse current b-ITU-T K.28: Maximum value of peak impulse current of specified amplitude and waveshape that may be applied without causing degradation. 3.1.19 sparkover b-IEC 60050-212: Disruptive discharge in a gaseous o
35、r liquid insulating material. 3.1.20 surge b-ITU-T K.96: Temporary disturbance on the conductors of an electrical service caused by an electrical event not related to the service. Rec. ITU-T K.117 (12/2016) 3 NOTE For non-linear SPCs a surge event is defined as an overvoltage or overcurrent or both.
36、 3.1.21 surge protective component (SPC) b-ITU-T K.96: Component specifically included in a device or equipment for the mitigation of the onward propagation of overvoltages or overcurrents or both. 3.1.22 surge protective device (SPD) b-ITU-T K.96: Device that mitigates the onward propagation of ove
37、rvoltages or overcurrents or both. 3.1.23 two-port b-IEC 60050-131: Device or network with two separate ports. 3.2 Terms defined in this Recommendation None. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: GDT Gas Discharge Tube IR Insulation Resistanc
38、e PD Powered Device/equipment PE Protective Earth PoE Power over Ethernet PSE Power Sourcing Equipment RJ45 Registered Jack #45 SPC Surge Protective Component SPD Surge Protective Device 5 Conventions 5.1 Connections The connection designation used in this Recommendation corresponds to the normal Et
39、hernet cable RJ45 contacts. Figure 1 shows the RJ45 contact numbers that are associated with signal connections and the PoE power feed modes. When an SPD does not use a RJ45 receptacle but uses, for example, a hard-wired cable connection, the terminal notations may be different. A hard-wire connecto
40、r may be required when the RJ45 contact currents exceed 1 kA or voltages between adjacent contacts will exceed 4 kV. The SPD configuration is assumed as in-line (2 port) with the test being applied to one port and the let-through surge measured on the other terminated port. 4 Rec. ITU-T K.117 (12/20
41、16) Figure 1 Ethernet RJ45 contact connections 5.2 Protective function This Recommendation tries to be technology neutral on the surge protective components (SPCs) used in the SPD. SPDs using voltage limiting components or isolating components, or both are tested with the SPD terminated. Figures 2 a
42、nd 3 show examples of a voltage limiting gas discharge tube (GDT) and isolating transformer in a common-mode surge test with the termination connected. Figure 2 GDT common-mode voltage limiting (partial circuit for only one twisted pair) Figure 3 Isolating transformer common-mode voltage blocking (p
43、artial circuit for only one twisted pair) 6 Electrical parameters The objective of an Ethernet SPD is to mitigate the cable surge levels down to levels that the equipment port can withstand. Cable surges can be common mode or differential mode. In addition Rec. ITU-T K.117 (12/2016) 5 the SPD must n
44、ot generate an excessive differential surge in common-mode surge operation; see Tables 2 and 3 for preferred maximum differential surge values. Three b-IEC 60664-2-1 preferred values of generator charging voltage are used: 2.5 kV, 6 kV and 12 kV. Manufacturers may also define levels to suit specific
45、 applications. SPDs rated for 2.5 kV are intended to protect equipment ports that do not meet a basic port withstand voltage of 2.5 kV. SPDs rated for 6 kV are intended to protect equipment ports that have a basic port withstand voltage of 2.5 kV but the equipment has been installed in an environmen
46、t that requires an enhanced 6 kV capability. SPDs rated for 12 kV are intended for severe installation environments to protect equipment ports that only have the basic (2.5 kV) or enhanced (6 kV) withstand voltages. The testing assumes all 8 Ethernet conductors are protected. Where the SPD is design
47、ed to protect a lesser number of conductors and surge mode requirements (e.g. non-PoE) only the appropriate SPD equipment terminals are tested and measured. 6.1 Common-mode surge The purpose of this test is to measure the impulse limiting voltage at the SPD port connecting to the equipment Ethernet
48、port. The test circuit is shown in Figure 4. To test this, set the generator charge voltage to the required level from Table 1 and surge the SPD while recording an SPD equipment port terminal voltage. Record the terminal peak voltage measured. Repeat this test with the generator voltage polarity rev
49、ersed. Repeat this procedure until all the port terminals have been measured for positive and negative surges and their peak voltage values have been recorded. For each configuration a minimum of three surges must be applied and the recorded value is the highest measured value. Finally, measure the d.c. insulation resistance for terminals 1 to 8 of the SPD cable port, as described in clause 7.1. Figure 4 Impulse limiting voltage under common-mode surge conditions 6 Rec. ITU-T K.117 (12/2016)
