Low-voltage networks are electricity networks that supply end users with electrical energy. They transport alternating current with a frequency of 50 Hz as single- phase current with 230 V and three-phase current or three-phase current with 400 V to the sockets of the end users.
Low-voltage grids are the lowest level in the power grid hierarchy. They are interconnected networks connected to medium voltage networks. The connection to the higher voltage level is made via transformers, which ensure the appropriate voltage adjustment. Electricity is transported via overhead lines and underground cables. This applies to all voltage levels. Power transmissionworks with three phase-carrying outer conductors( L1, L2, L3), the neutral conductor (N) and the protective conductor( PE).