Electromagnetic Compatibility (EMC) is the ability of electronic apparatus to operate in its intended environment without suffering unacceptable degradation or causing unintentional degradation to other apparatus.
The requirements for the control of EMC are embodied in the European EMC Directive, 2004/108/EC, which replaced 89/336/EEC on 20th July 2007. The Directive applies to all electrical and electronic apparatus (unless covered by other, more specific directives), including that operating in the railway environment.
In relation to the EMC Directive, the EN 50121 series of standards are available specifically for the railway environment. This series is subdivided into the following parts:
The 2006 version of EN 50121 has now been harmonised: assessing apparatus and fixed installations to the standard now provides a presumption of conformity.
In addition to EN 50121, there may be other requirements that manufacturers need to consider which may be defined in Railway Group Standards, for example.
The Railway Standards and Safety Board (RSSB) group standard GE/RT 8015 – Electromagnetic Compatibility between railway infrastructure and trains mandates requirements for the management of EMC between the railway infrastructure and trains to enable safe operation to be assured. This is cross-referenced with GE/RT 8270 Issue 2 – Assessment of Compatibility of Rolling Stock and Infrastructure, the updated standard dealing with route acceptance.
Similarly, London Underground Limited (LUL) document G-222, a Manual of EMC Best Practice, defines and clarifies the key EMC requirements for all types of new, modified and “off the shelf” systems. It also defines the requirements for the EMC Control Plan, Test Plan and Test Reports as shown in the EMC management strategy in Figure 1.
One of the key success factors in EMC management is ensuring that EMC is considered from the outset of the project and that all parties involved are fully aware of their obligations.
This is best achieved through the use of an EMC Management Plan, sometimes referred to as an EMC Control Plan.
Under the new EMC Directive (2004/108/EC), there is a single route to demonstrating compliance:– the production of Technical Documentation, which demonstrates the conformity of the apparatus with the essential requirements of the Directive.
Essentially a manufacturer must demonstrate that the apparatus in question is designed to meet the EMC requirements of the operating environment. This will be accomplished by showing that appropriate measures have been taken in the design, which are verified by test data and/or a theoretical assessment. For larger projects, supporting evidence will include EMC management, control and test plans, as shown in Figure 1.
The Technical Documentation may include a report or certificate from an EMC Notified Body asserting that the Documentation does demonstrate the apparatus’ conformity to the essential requirements of theDirective.
An EMC Notified Body is an independent third party, which satisfies certain requirements including technical competence, professionalism of personnel and possession of civil liability insurance. In the UK Notified Bodies, such as York EMC Services Ltd, are appointed by the BIS (formerly the DTI) and assessed by UKAS.
NB: The manufacturer is ultimately responsible for the Declaration of Conformity to the Directive.
York EMC Services is a well-established market leader for the provision of EMC services to the railway industry. We offer a range of consultancy, testing and training services. Specifically we can provide:
We have a solid track record in providing EMC Services for major railway projects around the world, including:
Last Updated: 2008-Feb-13