BS EN 50121-5:2017+A1:2019

What is BS EN 50121-5 - Emission and immunity of power supply of railway apparatus about?  

BS EN 50121 is a series of the European standard on railway applications that discusses electromagnetic compatibility so as to ensure an adequate level of emissions and immunity for rolling stock apparatus. 

BS EN 50121-5 is the fifth part of the BS EN 50121 series of documents that specifies emission and immunity aspects of EMC for electrical and electronic apparatus and systems intended for use in railway fixed installations for power supply. 

BS EN 50121-5 includes the power feed to the apparatus, the apparatus itself with its protective control circuits, trackside items such as switching stations, power autotransformers, booster transformers, substation power switchgear and power switchgear to other longitudinal and local supplies. 

Note: BS EN 50121-5 does not cover the following cases: 

• Which may occur with an extremely low probability of occurrence in any location 
• Where highly susceptible apparatus will be used in close proximity of the equipment covered by this standard, in which case further measures may have to be taken 

Who is BS EN 50121-5 - Emission and immunity of power supply of railway apparatus for? 

BS EN 50121-5 on railway applications is applicable to: 

• Manufacturers of railway rolling stock 
• Designers and users of electrical equipment 
• Railway engineer 
• Mechanical engineer 

Why should you use BS EN 50121-5 - Emission and immunity of power supply of railway apparatus? 

Electromagnetic compatibility (EMC) between electrical and electronic systems is an essential requirement for the reliable and safe operation of the train. 

BS EN 50121-5 specifies emissions testing and restrictions over a wide frequency range, as well as electrical and electronic apparatus functioning for use in railway fixed installations for power supply. 

The immunity test requirements for apparatus are addressed in BS EN 50121-5, which is used by manufacturers to evaluate the configuration and mode of operation during the tests, as well as the supply voltage rate. 

Overall, BS EN 50121-5 guides you through the EMC in railways that ensures the generic performance of signalling, traction, telecommunications and radiocommunications systems. 

In this way, the railway industry endeavours to reduce the risk of incidents and accidents occurring through electromagnetic emission and immunity characteristics of that equipment through identification processes and risk mitigation. 

What’s changed since the last update?  

BS EN 50121-5:2017+A1:2019 supersedes BS EN 50121-5:2015. BS EN 50121-5:2017+A1:2019 includes some technical changes with respect to BS EN 50121-5:2015. These include: 

• Clarification of scope (Clause 1) and set dated normative references (Clause 2) 
• Emission requirement extended in the frequency range 1 GHz to 6 GHz  
• Immunity requirement extended in the frequency range 5,1 GHz to 6 GHz
• Removal of limits for radiated H-fields in the frequency range 9 kHz to 150 kHz  
• Revision of Annex ZZ.