How to protect yourself from a zero cliff if you decide to make a zero?
Hello. The apartment building is old-built, there is no ground loop, phase and zero enter the apartment. I plan to take the grounding of the housings of electrical appliances from the zero bus in the apartment panel. Need protection against a zero break, since voltage will appear on the neutral and ground conductors. You can install a voltage relay with a contactor, which will turn off both phase and zero. But I would like to do without a relay and a contactor. Advise more options. Thank.
If grounding is not provided in your house, then it is highly not recommended to carry out grounding, since this is fraught with the appearance of voltage on the grounded cases of electrical appliances - you wrote correctly. No one practices such a scheme, in this case it is safer to operate the wiring without grounding at all. Zero will burn out in the house or someone will disconnect it or the cable will be damaged - and you will immediately have voltage on all electrical appliances. Fractions of a second, until the contactor works, is enough to receive an electric shock. Also, it cannot be ruled out that the voltage relay may fail and not open the contact - then the voltage will not be removed at all. If there is a zero break after the voltage relay, then in this situation the voltage will not be removed either. In general, such grounding will be deadly, do not do this.
What else can be done, safer options, you can find out from our article: https://our.electricianexp.com/en/kak-sdelat-bezopasnoe-zazemlenie-v-kvartire.html