BS EN 50121-1:2015 pdf download – Railway applications — Electromagnetic compatibility Part 1 : General
This Part 1 of the European standards series EN 50121 outlines the structure and the content of the whole set. It specifies the performance criteria applicable to the whole standards series. Clause 4 provides information about the EMC management.
This part alone is not sufficient to give presumption of conformity to the essential requirements of the EMC-Directive and is intended to be used in conjunction with other parts of this standard. Annex A describes the characteristics of the railway system which affect electromagnetic compatibility (EMC) behaviour. Phenomena excluded from the set are Nuclear EM pulse, abnormal operating conditions (e.g. fault conditions) and the induction effects of direct lightning strike. Emission limits at the railway system boundary do not apply to intentional transmitters within the railway system boundaries. Safety considerations are not covered by this set of standards. The biological effects of non-ionising radiation as well as apparatus for medical assistance, such as pacemakers, are not considered here.
a.c. alternating current
d.c. direct current
E electric (field)
EMC electromagnetic compatibility
GTO gate turnoff (transistor)
H magnetic (field)
IGBT insulated gate bipolar transistor
RF radio frequency
For the purpose of this document, definitions related to EMC and to relevant phenomena may be found in IEC 60050-161.
Other parts of this European Standard may contain specific definitions.
3 Performance criteria
NOTE This clause is based on EN 61000-6-2:2005.
The variety and the diversity of the apparatus within the scope of this set of standards makes it difficult to define precise criteria for the evaluation of the immunity test results.
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.
4 Management of EMC
The railway system is a complex installation with moving sources of electromagnetic energy and the application of the EMC standards in the EN 50121 series 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. For any new subsystem introduced within the railway systems boundary, potential sources and victims as well the coupling mechanisms between these sources and victims shall be considered. The EMC plan shall make reference to the basic EMC phenomena described in the EN 61000-series as applicable.