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GB/T 24338 consists of the following parts, under ther general title Railway Applications — Electromagnetic Compatibility:
— Part 1: General;
— Part 2: Emission of the Whole Railway System to the Outside World;
— Part 3-1: Rolling Stock — Train and Complete Vehicle;
— Part 3-2: Rolling Stock — Apparatus;
— Part 4: Emission and Immunity of the Signalling and Telecommunications Apparatus;
— Part 5: Emission and Immunity of Fixed Power Supply Apparatus and Systems.
This part is Part 1 of GB/T 24338.
This part is drafted in accordance with the rules given in the GB/T 1.1-2009.
This standard replaces the GB/T 24338.1-2009 Railway Applications — Electromagnetic Compatibility — Part 1: General in whole. The following technical deviations have been made with respect to the GB/T 24338.1-2009 (the previous edition).
— modification of the instructions in this part that shall be used in conjunction with other parts of GB/T 24338 (see Clause 1; Clause 1 of Edition 2009);
— addition of normative references GB/T 28807 (see Clause 2);
— addition of the requirements of consideration shall be given to possible electromagnetic interference when new auxiliary apparatus are added to the railway applications (see Clause 5);
— addition of the requirements for the management process to achieve EMC between rolling stock andtrain detection systems (see Clause 5);
— modification of the components of electric traction systems (see A.5; A.5 of Edition 2009);
— addition of the indication of how the track circuit detects the presence of a train (see A.7.5);
— removal of Annex B Management of EMC at the Interface between Railway Infrastructures and Trains (see Annex B of Edition 2009).
This part has been redrafted and modified adoption of International Standard IEC 62236-1:2008 Railway Applications — Electromagnetic Compatibility — Part 1: General.
There are technical deviations between this part and the International Standard IEC 62236-1:2008, and such deviations have been marked by perpendicular single line (|) in the outer side page margin of the corresponding clauses. The specific technical deviations, together with their justifications, are given below:
— adjustment on technical deviations has been made in Normative References of this part so that the technical conditions in China are met; the adjustment is concentratedly reflected in Clause 2 Normative References, see the followings for details:
IEC 60050-161 is replaced by GB/T 4365, which is identical with the international standard;
IEC 61000-6-2 is replaced by GB/T 17799.2, which is identical with the international standard;
IEC 62427 is replaced by GB/T 28807, which is identical with the international standard.
— modification of the description of this part shall be used in conjunction with other parts of GB/T 24338; and description of the limitations of the separate application of this part (see Clause 1);
— addition of the requirements of consideration shall be given to possible electromagnetic interference when new auxiliary apparatus are added to the railway applications, in order to improve this standard (see Clause 5);
— modification of the components of electric traction systems for practical applications (see A.5);
— addition of the indication of how the track circuit detects the presence of a train, in order to improve this standard (see A.7.5).
Attention is drawn to the possibility that some of the content of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all of such patent rights.
This part was proposed by National Railway Administration of the People's Republic of China.
This part is under the jurisdiction of SAC/TC 278 (National Technical Committee 278 on Traction Electrical Apparatus and System of Standardization Administration of China).
Drafting organizations of this part: Zhuzhou CRRC Times Electric Co., Ltd., Standards and Metrology Institute of China Academy of Railway Sciences, Beijing Jiaotong University, CRRC Qingdao Sifang Locomotive & Rolling Stock Co., Ltd. and China Railway Electrification Survey Design & Research Institute.
Chief drafting staff of this part: Yu Dinghua, Song Rui, Fan Zuocheng, Zhou Kesheng, Xiao Shi, Liu Aihua.
The previous editions of this part are as follows:
— GB/T 24338.1-2009.
Introduction
GB/T 24338 (all parts) provides both a framework for managing the EMC for railways and also specifies the limits for the electromagnetic (EM) emission of the railway as a whole to the outside world and for the EM emission and immunity for equipment operating within the railway. The latter must be compatible with the emission limits set for the railway as a whole and also provides for establishing confidence in equipment being Fit For Purpose in the Railway environment. There are different stationary emission limits set for trams/trolleybuses and for metro/mainline railways. The frequency covered by GB/T 24338 (all parts) is in the range from d.c. to 400 GHz. No measurements need to be performed at frequencies where no requirement is specified. The limits for EMC phenomena are set so that the railway as a whole achieves electromagnetic compatibility with the outside world, and between the various parts of the railway. Throughout the GB/T 24338, the immunity levels are chosen to ensure a reasonable level of EMC with other apparatus within the local railway environment and with emissions which enter the railway from the outside world. Limits are also placed on EM emission by railways into the outside world.
The compatibility between railway emissions and their external environment is based upon emission limits from the railways being set by considering results from measurements. Given that the general compatibility between railways and their environment was satisfactory at the time these measurements were made and subsequent experience of applying the limits has confirmed their acceptability, compliance with this part has been judged to give satisfactory compatibility. The immunity and emission levels do not of themselves guarantee that the railway will have satisfactory compliance with its neighbours. In exceptional circumstances, for instance near a “special location” which has unusually high levels of EM interference, the railway system may require additional measures to be taken to ensure proper compatibility. Particular care should be taken when in proximity to equipment such as radio transmission equipment, military or medical installations. In particular, attention is drawn to any magnetic imaging equipment in hospitals that may be near to urban transport. In all these cases, compatibility must be achieved with consultation and co-operation between the interested parties.
The immunity and emission levels do not of themselves guarantee that integration of the apparatus within the railway will necessarily be satisfactory. GB/T 24338 cannot cover all the possible configurations of apparatus, but the test levels are sufficient to achieve satisfactory EMC in the majority of cases. In exceptional circumstances, for instance near a “special location” which has unusually high levels of EM interference, the system may require additional measures to be taken to ensure proper operation. The resolution of this is a matter for discussion between the equipment supplier and the project manager, infrastructure controller or equivalent.
The railway apparatus is assembled into large systems and installations, such as trains and signalling control centres. Details are given in Annex A. It is not, therefore, possible to establish immunity tests and limits for these large assemblies. The immunity levels for the apparatus will normally ensure reliable operation, but it is necessary to prepare an EMC management plan to deal with complex situations or to deal with specific circumstances. For example the passage of the railway line close to a high power radio transmitter which produces abnormally high field strengths. Special conditions may have to be applied for railway equipment which has to work near such a transmitter and these will be specified in the specification.
Railway Applications — Electromagnetic Compatibility — Part 1: General
1 Scope
This part of GB/T 24338 specifies the structure and the content of other parts of GB/T 24338.
This part specifies performance criteria that apply to the whole series. Clause 5 gives information on management of Electromagnetic Compatibility (EMC).
The use of this part alone is not sufficient to determine compliance with the basic requirements of the EMC specification. It is also considered in conjunction with other parts of GB/T 24338.
Annex A describes the characteristics of the railway system which affect EMC behaviour.
Phenomena excluded from this part are as follows: nuclear EM pulse, abnormal operating conditionsand the induction effects of direct lightning strike.
Emission limits at the railway boundary do not apply to intentional transmitters within the railway boundaries.
Safety considerations are not covered by this part.
The biological effects of non-ionising radiation as well as apparatus for medical assistance, such as pacemakers, are not considered in this part.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 4365 Electrotechnical Terminology — Electromagnetic Compatibility [GB/T 4365-2003, IEC 60050(161):1990, IDT]
GB/T 17799.2 Electromagnetic Compatibility — Generic Standars — Immunity for Industrial Environments (GB/T 17799.2-2003, IEC 61000-6-2:1999, IDT)
GB/T 28807 Railway Applications — Compatibility between Rolling Stock and Train Detection Systems (GB/T 28807-2012, IEC 62427:2007, IDT)
3 Terms and Definitions
For the purposes of this document, the terms and definitions given in GB/T 4365 apply.
4 Performance Criteria
This clause is based on GB/T 17799.2.
The variety and the diversity of the apparatus within the scope of GB/T 24338 (all parts) makes it difficult to define precise criteria for the evaluation of the immunity test results.
If, as a result of the application of the tests defined in GB/T 24338 (all parts), the apparatus becomes dangerous or unsafe, the apparatus shall be deemed to have failed the test.
A functional description and a definition of performance criteria, during or as a consequence of the EMC testing, shall be provided by the manufacturer and noted in the test report, based on the following criteria:
— Performance criterion A: The apparatus shall continue to operate as intended during and after the test. No degradation of performance or loss of function is allowed below a performance level specified by the manufacturer, when the apparatus is used as intended. The performance level may be replaced by a permissible loss of performance. If the minimum performance level or the permissible performance loss is not specified by the manufacturer, either of these may be derived from the product description and documentation, and from what the user may reasonably expect from the apparatus if used as intended.
— Performance criterion B: The apparatus shall continue to operate as intended after the test. No degradation of performance or loss of function is allowed below a performance level specified by the manufacturer, when the apparatus is used as intended. The performance level may be replaced by a permissible loss of performance. During the test, degradation of performance is however allowed. No change of actual operating state or stored data is allowed. If the minimum performance level or the permissible performance loss is not specified by the manufacturer, either of these may be derived from the product description and documentation, and from what the user may reasonably expect from the apparatus if used as intended.
— Performance criterion C: Temporary loss of function is allowed, provided the function is self- recoverable or can be restored by the operation of the controls.
5 Management of EMC
The railway is a complex installation with moving sources of electromagnetic energy and the application of the GB/T 24338 (all parts) is not a guarantee of satisfactory performance. There may be cases where apparatus has to be positioned in restricted spaces or added to an existing assembly, with the possible creation of environments of unusual severity. All cases shall be considered with respect to a formal plan for the management of EMC. This plan should be established at as early a stage of the project as is possible.
Consideration shall be given to possible sources of interference and sensitive equipment and the coupling mechanism between the equipment when new auxiliary apparatus are added to the railway applications.
Refer to GB/T 28807 for the management process to achieve EMC between rolling stock and train detection systems.
Foreword II
Introduction V
1 Scope
2 Normative references
3 Terms and Definitions
4 Performance Criteria
5 Management of EMC
Annex A (Informative) The Railway System
