At high frequencies the self-inductance of the lines clearly plays the dominant role. This remains true even if we take into account the increasing apparent resistance of the line due to the skin effect, which is not negligible for fast transients and digital signals.
Following Kirchhoff’s laws, the disturbing signals may spread over the installation of an entire facility and may even affect the installations of neighbouring facilities. To minimise the galvanic coupling it is necessary to avoid connections between independent systems and, in cases where connections are necessary, to keep their self-inductance as low as possible. Generally galvanic decoupling of electrical power supply circuits can be achieved more easily when a TN-S system is used rather than a TN-C system.