scope:

This part of the IEC 61643 series is applicable to devices for surge protection against indirect 183 and direct effects of lightning or other transient overvoltages. 184 These devices are intended to be connected to DC power circuits and equipment rated up to 185 1 500 V DC Performance and safety requirements, tests and ratings are specified in this 186 standard. These devices contain at least one nonlinear component and are intended to limit 187 surge voltages and divert surge currents. 188 The test requirements provided by this standard are based on the assumption that the SPD is 189 connected to a DC power circuit fed by a power source providing a linear voltage-current 190 characteristic. When the SPD is to be connected to a different kind of source, careful 191 consideration is required. This mainly applies with regard to system and fault conditions to be 192 expected in such a system (e.g. expected short circuit current, TOV-stresses). 193 This standard can apply for railway applications, when related product standards do not exist 194 for that area or for certain applications.