Why doesn’t zero shock?
Good day. For several months I have been tormented by the question. With a fluorescent lamp (energy saving) working, I touched the neutral wire (bare) with one hand, and not only touched it, I held on to it for several seconds. However, I did not feel a tingling sensation, nothing. And then my knowledge diverges. As far as I understand the operation of alternating current, the phase and zero in the outlet change places with a certain frequency. Hence the questions:
- Why does a screwdriver indicator light on only one contact (per phase) if the current flow changes?
- Continuing the first question. Why does the multimeter show 220 volts when connected to + (plus) to the phase, and (minus, gnd) when connected to the phase, the multimeter shows -220 volts. Those. does the ac in the outlet still have a minus?
- And from here the most important question. How safe is this same minus in the outlet (zero)? Is it possible to hold onto a consumer while working without harm to health? And if not, can it be somehow protected? Purely theoretically, what can be done to hold on to a bare zero while standing in a bath of water, can a diode be hung on a wire? )) I want to close the question for myself about this same zero and I was lucky to understand that I was holding on to the wire and was insulated with the rubber sole of the sneakers, or that the zero in the socket was really safe under any conditions (loads).
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Hello! Electric shock occurs if there is a current path. If you stood on a surface that does not conduct current, then when you touch, even to the zero, even to the phase conductor, there will be no electric shock, since there is no way for the current to pass. But if you touch two wires simultaneously, you will get an electric shock, since in this case there will be a path of current flow between the hands.
Alternating current is an electric current that changes over time in magnitude and direction. Current flows through the conductors if a load is connected to them. If there is no load, then no current flows through the neutral or phase conductor.
1. The indicator screwdriver shows the presence of potential - there is potential on the phase, on the neutral conductor the potential is zero.
2. The multimeter, when measuring the voltage in the AC network, shows 220 V, regardless of how you connect the probes. In a direct current network it will show 220 V, and if the probes are interchanged, then -220 V.
3. If the load is not connected, then no current flows through the neutral conductor, there is no dangerous potential on it. But when the minimum load is connected, a current begins to flow through this conductor and if you touch it and at the same time there will be a current path (for example, through the legs), then you will get an electric shock. And if there is a different potential between the neutral conductor and the bathtub with water, this will also lead to electric shock. Zero in the wiring serves solely to power the load and should not be touched to avoid negative consequences.
I found an explanation for myself. The phase, as it were everywhere, is simply cut and you are always connected to one end of the wire (this is the ground), you are standing on it and appropriately connected to zero. When you touch the phase wire, it hits you from the sole as well as from the outlet. But if you raise the house into the air it turns out it does not matter where what. You can hammer the pin with the phase into the wall and everything will be vice versa. It’s only interesting then how the control screwdriver works if the person is isolated.
Do not do electrical work) not yours