The test tube is lit at "zero" - what does that mean?

Hello.
In the installation in the house on the first floor, I have a problem with the zero cable. In a few light sockets and switches, the test tube will glow slightly on the neutral wire. On the lead with the test tube, the light is normally lit. What does it mean? What could be the reason for this?
Greetings.

Probably a "weak" zero, i.e. no contact on some connection - continuation of zero from socket to socket. But on the circuit breakers it would mean that the problem is at the source of this installation (main box, switchgear)
Greetings J.

And are the devices connected to these sockets working properly? are the lamps shining ??

Use a normal pointer.

Hello.
Check as Admajur advised you, turn off the power and tighten all possible connections, I believe that the problem will disappear.
George.

All receivers are working properly. Both the light and the receivers connected to the sockets are working properly.
What is a normal pointer? Is it a multimeter?

Hello, what do you mean when you write a zero wire in switches? Because if the wires for incandescent lamps, the glow of a neon lamp on them in the absence of a light bulb is a normal phenomenon.
As for the sockets, I also do not know what cable you mean because, as Bronek22 writes, a voltage of several dozen V is needed to ignite the neon lamp and it is difficult for me to imagine that with such a voltage drop, the receivers will work properly, unless it is a protective conductor not connected somewhere.

Indicator neon / test tube / is not an indicator. When I was still working as an electrician, I had to pass health and safety exams every few years. For finding that a neon lamp is a work tool, the examiner fired the culprit with a bang and ... see you with mc ... According to it, and it is true, the reliable indicator is two 15W / 230V bulbs connected in series. Why in series? Well, because the inter-wire voltage was often checked with the same tester. I had friends who for this reason / neon lamp lighting / I worked in a gas plant tried to stop the production cycle, because ... it is lit zero, so there is a breakdown in the installation.Luckily, I managed to intervene in time. us then ... So if you use a neon indicator, always check the voltage after it with 2 low power bulbs at 230V connected in series. Do not use numeric meters. these, because they will show the same as the neon lamp.

Often, even DMMs show voltage at the sockets, even though the switch or fuse is off. Analog meters with low internal resistance will not show any voltage in this case.
The neon indicator is just for indicative assessment.

Hello

The neon lamp is a specific gadget (not to write - a tool). It consists of a gas discharge lamp and a current limiting resistor. Like every receiver of electric energy (it converts it into light energy), it has two "clamps". One is the tip of the screwdriver that serves as the probe, the other is as reference .... Exactly where is the other end connected?

It may be as Jurek says (adamjur1), or it may be that everything is fine with "zero", but not very much with reference (eg due to some other failure). The presence of an electrician is highly recommended.

kisses
- GIFT-

Hello, join the topic.

I also noticed that the test tube glows slightly after touching the neutral wire, it is not so in other sockets.

Is it normal?

The reason may be neutral or phase wire?

Hello
The problem is the zero circuit, just tighten the individual connections and the problem will pass.
George

I support measurements with a light bulb and special devices, a neon lamp is only useful when we know what we are doing in the installation. it is not suitable for diagnosis.
I have encountered a glowing working and protective zero many times as well, it is enough if they are bridged :)

most often it is the fault of devices included in the installations, e.g. washing machines and other larger ones - even though they function normally

the problem often arises in older 2-wire installations - we can even have a protective zero at home, as needed, but it must be connected to a real earth, otherwise it will shine
greetings

sebaele22 wrote:

The reason may be neutral or phase wire?

The reason is a person who acts as a lining for a charged capacitor in a well-insulated room (plastic floor, dielectric shoes, insulating paints, relative humidity close to zero).
The cladding has 115V in relation to the neutral and phase conductor.

Interesting discussion so I'll throw in my pebble. Have you not encountered the phenomenon when we grab the probe of an oscilloscope and on the screen many waveforms, including high-voltage ones (e.g. 100V)? And yet we do not power this probe from any network. Why not a neon lamp? A human being wants or is not a great antenna and it is certain that the amount of charge he induces depends on the coincidence.

Unscrew all bulbs and then check. Have you ever seen light switches with neon backlight? There, the socket "reaches 0" through the inserted light bulb

Bronek22 wrote:

That's not true. It is caused by a tension that cannot exist.
What is the law at zero to be 115V? You've got it mixed up.

What you describe is completely different. It is the mechanism of the neon lamp shining when we stand on a stool - and we are isolated from the ground.

It is 115V not at zero, but at human.
What is the difference between a stool and dielectric slippers?

wahoo wrote:

Hello.
In the installation in the house on the first floor, I have a problem with the zero cable. In a few light sockets and switches, the test tube will glow slightly on the neutral wire. On the lead with the test tube, the light is normal. What does it mean? What could be the reason for this?
Greetings.

check with another probe
your test tube is still lit is not correct.
tightening all connections is correct for service reasons but may not solve the problem.

Hello

I believe that Bronek22 is right, and that this situation has its source in some failure. I myself encountered a similar one once
the case when voltage was present on the "pin" connected to the "neutral" wire, although not 115V but about 90V (neon indicator
also shone). Interestingly, one of the electricians (it was in a company)
he said that this may sometimes be the case, unfortunately I do not know how he justified it.
As far as I remember, the problem resolved after tightening the screws in the switchboard.

Greetings.

Hello!

In order to receive a fairly precise answer, a precise question should be asked.
We do not know if the installation has a PEN conductor or PE and N conductors?

On the other hand, the first advice given should recommend checking the SWZ condition in bad nests. Such measurement will help direct the search.

You should also take into account the possibility of damaging the insulation of cables in the installation laid on the lower floor. In this case, tension may remain on the ground.

Currently, in multi-family buildings, some of the installations are run in the floor. The floor is reinforced with a steel wire mesh and under certain conditions the floor with respect to N is simply "live" and the neon lamp will show it. It will also light up on the pin in the socket. Sometimes the neon light applied to the wall also lights up and this does not indicate a faulty installation.

zubel wrote:

Currently, in multi-family buildings, some of the installations are run in the floor. The floor is reinforced with a steel wire mesh and under certain conditions the floor with respect to N is simply "live" and the neon lamp will show it. It will also light up on the pin in the socket. Sometimes the neon light applied to the wall also lights up and this does not indicate a faulty installation.

even if you are right, it doesn't add anything to the explanation of the glowing test tube, and the topic has become interesting and intriguing. I think there is some installation error.
I wonder if there is also such a phenomenon on the ground floor of the house some socket outlets are present.

After all, I wrote clearly. If the floor or wall are live, the neon lamp will shine on N or PE. No matter which end of the neon you touch to the "phase"

The neon lamp will glow on the PE conductor if the conductor has no continuity. (Not connected) There is something like capacitive reactance and therefore a potential difference appears on the PE conductor. You can do a little experiment even with a 3-wire cable, when we connect L and N and we do not connect PE, touching the end of the PE wire, the test tube will glow.