NA 022
DKE German Commission for Electrical, Electronic & Information Technologies of DIN and VDE
Technical rule
[CURRENT]
VDV 509
VDV 509
Application of residual current protective circuits in electrical power installations of dc urban rail systems
Title (German)
Einsatz von Fehlerstrom(FI)-Schutzschaltungen in elektrischen Energieanlagen von Gleichstrom-Nahverkehrsbahnen