High powered electronic equipment, together with low power microcontrollers and other electronic devices, is being installed on trains in great numbers. Electromagnetic compatibility has therefore become a critical issue for the design of train related apparatus as well as of the train as a whole.
BS EN 50121-3-1:2006 sets limits for electromagnetic emission and immunity in order to ensure a well functioning system within its intended environment.
Immunity limits are not given for the complete vehicle. Part 3-2 of this standard defines requirements for the apparatus installed in the rolling stock, since it is impractical to test the complete unit. An EMC plan shall be established for equipment covered by this standard.
BS EN 50121-3-1:2006 specifies the emission and immunity requirements for all types of rolling stock. It covers traction stock and train sets, as well as independent hauled stock. The scope of this part of the Standard ends at the interface of the stock with its respective energy inputs and outputs.
It specifies the emission and immunity requirements for all types of rolling stock. It covers traction stock and train sets including urban vehicles for use in city streets.
The frequency range considered is from d.c. to 400 GHz. No measurements need to be performed at frequencies where no requirement is specified.
The scope of this part of BS EN 50121-3-1:2006 ends at the interface of the rolling stock with its respective energy inputs and outputs. In the case of locomotives, train sets, trams etc., this is the current collector (pantograph, shoe gear). In the case of hauled stock, this is the a.c. or d.c. auxiliary power connector.
However, since the current collector is part of the traction stock, it is not entirely possible to exclude the effects of this interface with the power supply line. The slow moving test has been designed to minimise these effects.
Basically, all apparatus to be integrated into a vehicle shall meet the requirements of Part 3-2 of this standard. In exceptional cases, where apparatus meets another EMC Standard, but full compliance with Part 3-2 is not demonstrated, EMC shall be assured by adequate integration measures of the apparatus into the vehicle system and/or by an appropriate EMC analysis and test which justifies deviating from Part 3-2.
The electromagnetic interference concerning the railway system as a whole is dealt with in
BS EN 50121-2. These specific provisions are to be used in conjunction with the general provisions in BS EN 50121-1.
BS EN 50121-3-1:2006 supersedes BS EN 50121-3-1:2002 which has been withdrawn.
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