How to protect yourself from a zero break?
The situation was simulated: a zero break in the panel riser, 3 apartments for all in the same phase, the loads included are different in each apartment. Connection (N common for apartments) The L-N-PEN in the N shield is connected to PE.
Question: how to secure a bathroom with a metal washing machine. etc.? With a zero break in the riser in one of the apartments, PE will have a voltage of up to 400 volts (for example, if there is poor grounding or contact). The voltage relay will disconnect L and N, if there is no voltage relay, will the RCD disconnect? And what are the control sensors (possibly sound) for the PE wire in the apartment panel (for example, as a screwdriver for a phase test), if the phase appeared on the PE wire? Thank.