TDM wrote:
I think I understand, if I had less resistance, the shock would be "only" and only with the current consumed by the receiver.
You would need to have less resistance than the neutral wire, but in this case touching the battery terminals in the car would kill you.
The neutral wire can have a resistance greater than you only when there is a power failure, i.e. it burns zero. Apart from this, the neutral wire MUST be literally ZERO, i.e. zero volt - it should not hurt when touched. Of course, don't try to do this, but you can buy a neon tube and then you will understand that there is zero Volt at zero. Unless you have a fault and it's more than zero - then call an electrician quickly.
Quote:
Well, but there may be a coincidence that it would be better not to connect this mass? Then what ? Would it not interfere with the work of this lathe / milling machine? Wouldn't she electrocute? Does this have no effect on the operation of the device?
The milling machine only consists of a motor, unless it's CNC, but anyway, until there is no puncture, the milling machine should not have tension on the housing, because that means it is damaged or poorly made. If every purchased equipment could electrocute itself, old installations without an earth electrode would not have the right to exist. And I have such an installation (without an earth electrode).
Quote: Zero burnout or installation failure? It does not happen often, and even if it does, is there no protection against it?
Yes, it is a failure, in fact, it rarely happens, but it is probably this topic to protect against something like that. Are there any security features? It depends where you let go of the zero point, but rather the differential (RCD) should pop out.
Quote: These facilities are in the basement directly under the meter, there are two wires, so I give the can and connect the mass to zero in this box. I do not know if the RCD is not phase-cut in the event of such a breakdown
The differential disconnects the voltage when a current of approx. 30mA flows between the phase (after the RCD) and the neutral BEFORE THE DIFFERENTIAL, i.e. simply when the current flows through the ground or through you to the ground.
Quote: This electrician exactly what measurements should he take?
He should measure the grounding resistance on the rod / bucket / hoop that you buried.
One more thing - there are devices that electrocute when they are unearthed - for example a computer. This is not due to its defect, but rather to the presence of a filter in the computer power supply, which has a capacitor divider between the phase and zero, with a ground connection. Between the grounding of an ungrounded computer and some grounding (a pipe, anything larger, metal), there is a voltage of about 100V, while touching the housing and grounding causes a slight electric shock, although it is rather not life-threatening. Don't try, but don't be surprised when the neon tube shows you the phase between the unearthed ground and you.
Added after 7 [minutes]: I would like to add that in my basement there used to be an injection molding machine (not connected by anything) and it also did some kind of grounding - it was through it that I closed the circuit with the computer and then I started to be interested in the EMI filter in the computer power supply. You are probably surprised why some unearthed elements cause the flow of electricity even though they are not in contact with anything? For example, why is a person connected to a phase electrocuted even though he or she is standing in rubber boots? The answer is simple - every object separated by an insulator from the potential is a kind of capacitor - therefore the current will find its way not through the legs, but through the interaction of man - Earth.
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