EN 50155:2007 – Railway applications – Electronic equipment used on rolling stock
For peripheral units (measuring transducers etc.), or if the equipment is in a decentralized configuration, then if the above humidity stresses are exceeded, the actual humidity occurring at the location of the equipment concerned shall be used in the design.
4.2 Special service conditions Special arrangements shall be agreed between the appropriate parties involved when service conditions can be proved to be different from those mentioned in 2.1 (e.g. electronic equipment mounted on the bogie or integrated within a power converter etc.). Checks for the effectiveness of such arrangements can, if required, form the subject of optional type tests which can be carried out on the vehicle itself in accordance with methods to be agreed between the user and the manufacturer.
4.2.1 Atmospheric pollutants The equipment may be expected to be exposed throughout its life to various pollutants (e.g. oil mist, salt spray, conductive dust, sulphur dioxide.). The types of pollutants and their concentration should be defined in the tender documents.
5 Electrical service conditions 5.1 Power supply 5.1.1 Supply from accumulator battery The nominal voltage of equipment (U n ) so supplied shall be selected from amongst the following values: 24 V, 48 V, 72 V, 96 V, 110 V
NOTE 1 These nominal voltage values are given only as standardising values for the design of equipment. They should not be considered as the off load battery voltages since these are determined by the types of battery, the number of cells and the operating conditions.
NOTE 2 Different voltage variations may be used, following EN 60077. In this case compliance with the requirements should be defined by agreement between manufacturer and user.
5.1.1.1 Variations of voltage supply Electronic equipment supplied by accumulator batteries without a voltage stabilizing device shall operate satisfactorily for all the values of the supply voltage within the range defined below (measured at the input terminals of the equipment).
The supplier of the electronic equipment shall specify its power consumption in order to enable calculations for the battery cabling.
Minimum voltage: 0,7 U n
Nominal voltage: U n
Rated voltage: 1,15 U n
Maximum voltage: 1,25 U n
Voltage fluctuations (e.g. during start-up of auxiliary equipment or voltage oscillations of battery chargers) lying between 0,6 U n and 1,4 U n and not exceeding 0,1 s shall not cause deviation of function.
Voltage fluctuations lying between 1,25 U n and 1,4 U n and not exceeding 1 s shall not cause damage: equipment may not be fully functioning during these fluctuations.
In the case of thermal engines, see also 5.1.1.3.
EN 50155:2007 – Railway applications – Electronic equipment used on rolling stock