Risk of Electric Shock from Touching a Live Neutral Conductor

Hello, I have a question: in the neutral conductor in the electrical installation, current flows because the electric circuit is closed, it is logical, if you touch such a conductor while the device is working, will something happen? Are we going to get kicked? can we be shocked only when there is tension? If there is electricity in the cable and there is no voltage, then we will not be electrocuted if we touch it? Thanks for the answers

Two cases need to be considered. It used to be that zero was a working conductor with earth potential, i.e. the transformer's neutral point was grounded and the conductor was called PEN (protective neutral), between this conductor and the ground there should be no voltage greater than 50V, then the shock current that will flow through the human body will be the so-called long-lasting shock current, that is, one that you feel but does not kill.

In the second case, the neutral conductors are separated (always blue) and the neutral conductor (always blue) performs the working function, closes the phase currents, while the PE protective conductor is always yellow-green and it has the ground potential, there is never a possibility of a different potential on it, this one does not kick.

If the zero wire is correct, the voltage drop on it does not threaten our life. The voltage drop is nothing but U = I / R. If R is small, the current can be high. This is for the neutral wire. Do not touch the phase conductor (L).

trebuch1 U = I * R so if the resistance is high, the voltage is also greater for the same current

According to the Polish standard, the neutral "N" conductor is also treated as a phase conductor, and therefore it is also protected against electric shock, and the current flows in it. from the last 10 years, which should already be done with the so-called differential.

There is current in the work conductor, but there is no voltage drop (at least it shouldn't be). So if there is no voltage, nothing will happen to me if I touch it, is that it? And what about the current, it flows there, if I touch this wire, it won't flow through me? why? Summing up, there must be tension for an electric shock to occur?

From what I know from kuru SEP, first of all:

the human body resistance under normal conditions is taken at the level of 1000 OM

The mains voltage is rigid (it will not increase by itself unless the lightning strikes the mains)

Hence the conclusion that when connecting a person to the network, reading to a phase conductor, the current will flow only depending on the resistance of the human body, it will flow more by young, sick, women, children due to the decreasing resistance in these cases, and in terms of residual current protection they will actually work if you touch the neutral wire, but better not to check it, because I have to deal with electricians who connect a differential so that it will never work.

wromich wrote:

Current flows in the work conductor, but there is no voltage drop (at least it shouldn't be)

This is a theory contradiction test. You can't say that. because there are no conductors (copper wires) with resistance equal to zero.

I know what you are talking about, but I mean something completely different, namely: electrocution can occur when there is tension? If there is no voltage, but the current flows in the same way as in the neutral wire, will we not get electrocuted? If there is current in the conductor and there is no voltage and you touch such a conductor, nothing will happen? why?

A potential difference is needed for the current to flow. If we assume that the neutral wire has a ground potential, and the phase wire has a potential of 230V, there is a potential difference between them and after the receiver closes the circuit, the current will flow caused by the voltage drop on the given receiver.

If you are standing on the ground, your body has the potential of the earth, the neutral conductor has the same potential, so there is no potential difference between you and the conductor, and the current cannot flow.

It's a bit like draining the water from the tank, if the hose and the water level are at the same level, the water will not flow, but if you lower the hose at least a little, the water starts to fly faster, the greater the difference in levels.

Thank you so much for that. A bit of electricity will flow, however, because such a cable is not an ideal cable and there is a voltage drop on it, and therefore when you touch such a cable, the residual current device will work because it is very sensitive, I think right? However, if there was no voltage drop on this wire (idealization), then after touching the RCD would not work because the current would not flow, right?

BB55 proposes to perform a simple experiment on an installation protected by a residual current circuit breaker, the so-called differential. That is, touch the neutral wire with your bare hand with your finger, and touch the other hand to the wall, for example, so that there is earth power on the body. differential should work. So the question is from where the electricity turned it off (actually where the difference came from). is there prą or is it not ??

Interesting experience
... and if the installer screwed up the job and the blue wire is a phase wire, and if the differential doesn't work this time, then in the afterlife you'll have plenty of time to understand Ohm's law
greetings

Equalizing currents appear on the neutral wire due to the lack of symmetrical phase load, if you touch the wall that is "ideal" ground and the neutral one with asymmetry, the differential will work, besides, the voltage drops in the resistance of the wires may already be sufficient to make a decent difference it worked for 30mA, which is a tripping current, usually 16mA. a circuit with a bulb on this differential is enough to make it 16mA

dariusz1 wrote:

According to the Polish standard, the neutral "N" conductor is also treated as a phase conductor, and therefore it is also protected against electric shock, and the current flows in it. from the last 10 years, which should already be done with the so-called differential.

Can someone explain it to me? As far as I know, the differential can work with a current of several tens of mA (or rather the difference of currents flowing in the neutral and phase conductors). I stand on the ground and touch the neutral wire. And what? Where is this current that triggers the differential? And where does it come from, if in a properly made installation the voltage of the neutral conductor in relation to the ground usually does not exceed a few or a dozen V? It is possible only when we connect a receiver with a resistance much lower than a human between zero and earth (or a protective conductor). But don't say that when I touch zero, the differential will work, unless it has a threshold of 1mA. Or the leakage in the installation is so great that the differential is at the activation threshold.
The residual current device operates when current flows from the phase conductor to the earth or protective conductor.

Listen, I think that the answer to your question is the usual old type installation, where the neutral wire in the socket was connected to the grounding pin. Thus, the housing of the device that worked plugged into this socket had a housing tied with a wire with an N conductor, formerly called zero.

BB95 wrote:

Quote:

A potential difference is needed for the current to flow.

and that's how it really does it.
We consider the circuit in which we have:
1) power source - transformer
2) phase conductor resistance - wire resistance
3) receiver - also some resistance or impedance
4) resistance of the neutral conductor - wire resistance.



If current flows through the receiver, voltage drops occur on the resistances Rf, Z and Rn. Thus, at point A there is a potential higher than at point B. Since the resistances Rf and Rn are smaller than the impedance Z, the voltage drop at the receiver is also the greatest - almost an inch of the supply voltage.
Suppose that Rf and Rn have a resistance of about 1 Ohm (probable values) and that the Z of the receiver is a resistance (2kW heater) of about 26.5 Ohm. Power supply, of course, 230V; The current consumed is:
I = U / R where R is Rf + Z + Rn -> I = 230 / 28.5 = 8.07A
The voltage drop across Rf is:
Uf = I * Rf = 8.07V
For Rn we have the same, so the voltage drop across the receiver is:
Uz = 230-2 * 8.07 = 214V (almost).
This means that the potential of point A with respect to ground (ground) is 214 + 8.07 = 222.07V.
Point B has a potential to ground of 8.07V.

Assuming now that a 1000 Ohm resistance is connected between points B and C (human model), we get that as a result of the potential difference of these points, a current of the value:
I = U / R = 8.07 / 1000 = 8.07mA.

In such a situation, the RCD should not trip, because its activation threshold is about 50% of the rated value (if we have 30mA, the activation threshold is 15mA). If it works, it means that the resistance of the neutral wire is greater. Let's see that it is enough to increase the value of the resistance Rn twice, which is also not very improbable and we already have a potential of about 16V at point B with respect to ground. This will allow the current to activate the residual current device to flow.

So summing up:
The current flows through the neutral conductor during normal operation of the device. Therefore, a protective conductor has been separated in which no current can flow during normal operation.
Nevertheless, the potential of the neutral conductor to ground is relatively small and results from the resistance of the conductors.
Since there is some potential with respect to the ground of the neutral, it is possible for the current to flow through the "human model" to ground. This is due to Kirchhoff's law.

Finally, a note.
Dariusz1 wrote:

Quote:

BB55 proposes to perform a simple experiment on an installation protected by a residual current circuit breaker, the so-called differential. That is, touch the neutral wire with your bare hand with your finger, and touch the other hand to the wall, for example, so that there is earth power on the body.

Better not to touch the electricity :)

Instead of a hand, it is better to use an ordinary resistor with a value of about 1kOhm, preferably one resistor with a value of 470 Ohm and a potentiometer with a value of 10k Ohm (maybe more) connected in series. Everything, of course, with the right power and properly isolated.
And the last NOTE:

POWERFUL OPERATION IS ALWAYS DANGEROUS AND ALL SAFETY PRECAUTIONS SHOULD BE TAKEN.