It has been published the new edition of the standard EN 50121-3-2 "Railway applications, street cars, trolleybuses and subways. Electromagnetic compatibility — part 3-2: Rolling stock — Apparatus ". This recent update addresses the technical standard called from the harmonised standards EN 50155 "Railway applications, street cars, trolley bus applications — electronic equipment used on rolling stock "referred to by the European directive on the interoperability of the trans-European high speed rail system.
The new version, in force since may 2015, completely replaces the previous EN 50121-3-2 of 2006, that however will remain applicable until may 2018.
As has already happened for other updates in the railway sector, you have to expect that the manufacturers of these vehicles require the early implementation of the new rule before it becomes mandatory, given the time of completion of projects, the large number of components present and rather long lifetime of railway vehicles.
EMC News: appliances up to 6 GHz and new standards for measurement methods
EN 50121-3-2, concerning the electromagnetic compatibility, in the new version makes some substantial changes compared to the previous edition.
First emission and immunity measures extends to devices up to 6 GHz, taking into account, Like this, even telecommunications standards that use frequencies above 5 GHz, such as some variants of the standard WiFi.
The application of this rule ensures, then, the devices commonly used by passengers on these media do not interfere or are not bothered by electrical and electronic systems aboard railway vehicles.
A further innovation is the reference standard for the preparation of the environments and systems of measurement in the laboratory carrying out these electromagnetic compatibility testing. Unlike when indicated in the previous version, that this was a reference to standard EN 55011 "Industrial Equipment, Scientific and medical (ISM) – Radio disturbance characteristics – Limits and methods of measurement ", in the new version reference is made to the standards of the Group EN 55016 "Specification for equipment and methods of measurement of radio disturbance and immunity".
It then passes by the application of a rule of "niche", which concerns scientific equipment and measuring instruments, the application of a rule more general and widespread, that covers among other things all consumer equipment.
A tendency to converge towards a unique standardization
The last amendment shows how a process of convergence towards a unified way to perform measurements in products belonging to different categories and scopes, accordingly, fall under different directives. In this way the regulations follow the technical evolution and costume in place, in which the same dominant technologies permeate various areas and, at the same time, see live increasingly distinct time scopes. For example, to the common use of tablet, Laptops and wireless technologies on trains, planes and yachts.
A similar process of convergence is occurring even in the military, for example, in the case of equipment of various kinds provided to law enforcement and military bodies. According to current European legislation these equipments are exempted from compliance with the same limitations and the same criteria to which are subject electronic devices for civil use; However, in order to avoid electromagnetic compatibility issues that otherwise would have occurred, in recent years, is often asked to certify also the equipment according to the standards of civilian equipment.
Moreover, the application of safety standards civilians by the military says the principle that even for military personnel, like any other worker, health and safety must be protected from unnecessary risk.