1、 International Telecommunication Union ITU-T K.76TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (07/2008) SERIES K: PROTECTION AGAINST INTERFERENCE EMC requirements for telecommunication network equipment (9 kHz-150 kHz) Recommendation ITU-T K.76 Rec. ITU-T K.76 (07/2008) i Recommendation ITU-T K.7
2、6 EMC requirements for telecommunication network equipment (9 kHz-150 kHz) Summary Recommendation ITU-T K.76 specifies, for frequencies from 9-150 kHz, generalized conducted emissions requirements for telecommunication network equipment and an immunity requirement specific to telecommunication netwo
3、rk equipment with analogue voice interfaces. Source Recommendation ITU-T K.76 was approved on 7 July 2008 by ITU-T Study Group 5 (2005-2008) under Recommendation ITU-T A.8 procedure. Keywords 9-150 kHz, conducted emissions, conducted immunity, electromagnetic compatibility, low frequency, performanc
4、e criteria. ii Rec. ITU-T K.76 (07/2008) 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 Standardization Sector (ITU-T) is a permanent or
5、gan 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), which meets every four years, establishes the
6、 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 ITU-Ts purview, the necessary standards are
7、 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 Recommendation is voluntary. However, the Recommendati
8、on 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 “must“ and the negative equivalents are used t
9、o express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectua
10、l 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 this Recommendation, ITU had not received not
11、ice 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 database at http:/www.itu.int/ITU-T/ipr/. ITU
12、2009 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.76 (07/2008) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 2 4 Abbreviations and acronyms 2 5 Emissions 2 5.1 Equipment configuratio
13、n 2 5.2 DC power port emission. 3 6 Immunity 5 6.1 Test level 5 6.2 Test set-up 6 6.3 Method of measurement. 7 6.4 Performance criteria . 7 Appendix I Example of disturbances at low frequency 9 I.1 Audible noise caused by disturbance from rectifier. 9 I.2 Audible noise in telephone services provided
14、 from a central office 9 I.3 Trouble in LAN system 10 Bibliography. 11 iv Rec. ITU-T K.76 (07/2008) Introduction This Recommendation complements the electromagnetic compatibility (EMC) requirements for telecommunication network equipment contained in Recommendation ITU-T K.48 by specifying requireme
15、nts at frequencies from 9-150 kHz. Telecommunication network equipment can be influenced by or influence the electromagnetic environment at frequencies from 9-150 kHz. A necessity to analyse this frequency range was highlighted considering the influence that very low frequency noise has on analogue
16、voice communication. The first edition of this Recommendation covers direct current (DC) ports. Other ports could be considered in future editions of the Recommendation. Rec. ITU-T K.76 (07/2008) 1 Recommendation ITU-T K.76 EMC requirements for telecommunication network equipment (9 kHz-150 kHz) 1 S
17、cope This Recommendation considers continuous electromagnetic phenomena from 9-150 kHz. Impulsive low frequency phenomena are considered in other K-series Recommendations. Continuous phenomena above 150 kHz are covered by ITU-T K.48. Both the emissions of and the immunity to induced signals at frequ
18、encies from 9-150 kHz are taken into account in this Recommendation. This Recommendation defines test set-up, measurement methods, emission limits and immunity test levels for telecommunication network equipment. This Recommendation applies to all types of telecommunication network equipment. Due to
19、 the nature of the interference, the immunity test is applicable only to equipment having an analogue voice interface that could be influenced by disturbing signals in the voice frequency range. 2 References The following ITU-T Recommendations and other references contain provisions which, through r
20、eference 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 investigate the possibility of applying the m
21、ost 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 of a Recommendation. ITU-T K.48 Reco
22、mmendation ITU-T K.48 (2006), EMC requirements for telecommunication equipment Product family Recommendation. IEC CISPR 16-1-1 IEC CISPR 16-1-1 (2007), Specification for radio disturbance and immunity measuring apparatus and methods Part 1-1: Radio disturbance and immunity measuring apparatus Measur
23、ing apparatus. IEC CISPR 16-1-2 IEC CISPR 16-1-2 (2006), Specification for radio disturbance and immunity measuring apparatus and methods Part 1-2: Radio disturbance and immunity measuring apparatus Ancillary equipment Conducted disturbances. IEC CISPR 16-2-1 IEC CISPR 16-2-1 (2008), Specification f
24、or radio disturbance and immunity measuring apparatus and methods Part 2-1: Methods of measurement of disturbances and immunity Conducted disturbance measurements. IEC CISPR 22 IEC CISPR 22 (2008), Information technology equipment Radio disturbance characteristics Limits and methods of measurement.
25、2 Rec. ITU-T K.76 (07/2008) 3 Definitions This Recommendation defines the following terms: 3.1 continuous disturbance: Electromagnetic disturbance whose effects on a particular device or piece of equipment cannot be resolved into a succession of distinct effects. 3.2 fully populated equipment: Equip
26、ment designed to provide housing (slots) for a number of different functional modules (line cards, etc.), configured such that the full capacity (i.e., all slots) is populated with modules in a manner representative of intended use. 3.3 nominal current: The DC current consumption of a fully populate
27、d equipment powered at the nominal DC voltage when the equipment is operated in a manner representative of intended use. 3.4 nominal voltage: The value of the voltage that designates the type of supply declared by the manufacturer. 4 Abbreviations and acronyms This Recommendation uses the following
28、abbreviations and acronyms: ADN Artificial Direct Current Network CM Common-Mode DC Direct Current DSU Data Service Unit EMC ElectroMagnetic Compatibility EUT Equipment Under Test ISDN Integrated Services Digital Network LAN Local Area Network MDF Main Distribution Frame NM Normal-Mode RMS Root Mean
29、 Square SW Switching Equipment 5 Emissions The emissions at low frequency are in major part due to the cabling attached at the equipment; for this reason it is sufficient to measure the conducted emission from the cabling. Experience has been reported from telecommunication installations that emissi
30、ons at low frequency from some ports can cause trouble in telecommunication installations (see Appendix I). This Recommendation considers conducted emissions from the following cable ports: DC power ports. 5.1 Equipment configuration During the measurements, the telecommunication network equipment s
31、hall be powered at nominal voltage, operated at rated load conditions and have achieved a steady state (such that any transients on the current consumption associated with equipment power-up can be neglected). If the power consumption of the equipment changes significantly from one operational state
32、 to another, the equipment shall be tested in each operational state to determine the highest value of emission. Rec. ITU-T K.76 (07/2008) 3 The equipment shall be configured in a manner representative of intended use and exercised accordingly. Detailed equipment test conditions, for different types
33、 of products, are reported in clauses 6 and 7 of ITU-T K.48. 5.2 DC power port emission The emissions from DC power ports are divided into the following two frequency ranges: Range 1: from 25 Hz to 20 kHz (narrow-band noise). Range 2: from 20 kHz to 150 kHz. 5.2.1 Emissions in range 1 5.2.1.1 Limits
34、 The maximum level of noise emitted into the DC power supply system of the telecommunication network equipment is shown in Figure 1. The values shown in Figure 1 refer to the bandwidths given in Table 1. Table 1 Resolution bandwidths versus frequency range Frequency range Resolution bandwidth 25 Hz
35、to 10 kHz 10 Hz 10 kHz to 20 kHz 200 Hz or 300 Hz -50-45-40-35-30-25-20-15-1010 100 1000 10000 100000f (Hz)-21dBuV9787867772676257928225dBmFigure 1 Maximum levels of narrow-band noise 5.2.1.2 Measurement methods The EUT shall be connected to the DC power supply through an artificial network to provi
36、de defined impedance across the EUT at the point of measurement and to provide isolation from the noise on the DC power supply lines. This artificial network is referred to hereafter as the artificial DC network (ADN), an example of which is displayed in Figure 3. 4 Rec. ITU-T K.76 (07/2008) The mea
37、surement shall be made with a spectrum analyser or a receiver having the bandwidths shown in Table 1 for the relevant frequency ranges. The measurement circuit shall be as shown in Figure 2. The measurement shall be performed at three values of the powering voltage: the minimum, nominal and maximum
38、of the normal service voltage range. Zm= 50 (internal instrument impedance) ZcPrinted in Switzerland Geneva, 2009 SERIES OF ITU-T RECOMMENDATIONS Series A Organization of the work of ITU-T Series B Available Series C Available Series D General tariff principles Series E Overall network operation, te
39、lephone service, service operation and human factors Series F Non-telephone telecommunication services Series G Transmission systems and media, digital systems and networks Series H Audiovisual and multimedia systems Series I Integrated services digital network Series J Cable networks and transmissi
40、on of television, sound programme and other multimedia signals Series K Protection against interference Series L Construction, installation and protection of cables and other elements of outside plant Series M Telecommunication management, including TMN and network maintenance Series N Maintenance:
41、international sound programme and television transmission circuits Series O Specifications of measuring equipment Series P Telephone transmission quality, telephone installations, local line networks Series Q Switching and signalling Series R Telegraph transmission Series S Telegraph services termin
42、al equipment Series T Terminals for telematic services Series U Telegraph switching Series V Data communication over the telephone network Series W Available Series X Data networks, open system communications and security Series Y Global information infrastructure, Internet protocol aspects and next-generation networks Series Z Languages and general software aspects for telecommunication systems
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