3) In case of a-selective switch-off of a relay in the MV transmission network normally only a transmission cable will be switched off. Next the main protection of the distribution cable in which the fault occurred can still switch-off the fault correctly. Due to the N-1 redundancy no interruption of supply will occur. It is also possible however that the fault is in another cable of the same transmission network, resulting in switching off two cables instead of one. This can result in interruption in supply, but the chance that this will occur is small however