Differentiating Protective Conductor from Neutral in Same-Colored Wires

Question

Hello.
I would like to know how to determine which of two cables of the same color is protective and neutral. Because if we have three wires of the same color, we determine the phase by measuring the voltage between the three cables, but how to deduce which is N and which PE? Of course, I omit the colors of the wires here, because the PE should be yellow-green. The situation is presented as a hypothetical one, given by way of example.

elpapiotr · Answer

Hello. Dietz's ticks and after the problem.

krzysztooof · Answer

Yes, but the current will flow through both the LN and L-PE cables. Perhaps you did not understand the post exactly, I wrote it a bit chaotically, but I mean which of the two cables is neutral and which is protective. And can it be checked at all?
Or maybe the resistance of the PE conductor will be higher?

elpapiotr · Answer

Hello again. I have understood well and repeat my answer.

runcle · Answer

Current flows through PE only in emergency situations. Operating currents collected by single-phase receivers flow through N. So you can make a difference by hypothetically measuring the current in these conductors (when the network is loaded of course).

krzysztooof · Answer

I will write differently:
Three cables of the same blue color come out of the outlet. Of course, I will determine the phase one, because there will be a phase voltage between the other two. But how do you tell which one is protective and which one is neutral when both have zero potential?
Runcle, you wrote something that I know, but I mean the example above, when we do not have a load connected, but when we have cables led out from, for example, a lighting outlet.
Because it is normally distinguishable by its colors.

Added after 2 [minutes]:

ele_pp, could you please explain?

wujt · Answer

Straight on the other side of the cable, connect the dc 12 power supply and the meter will find which is plus and which is minus

jarecki 86 · Answer

If the circuit is protected with a differential, then the connection of a receiver between L and PE will cause the device to work. And if there is no RCD, then as my colleague mentioned ele_pp , put the clamps in the switchgear and everything becomes clear.

kasprzyk · Answer

Buddy, look for the other end of this wire, the source from which it is connected. kisses

Przemo1268 · Answer

Homemade way:
- You check with the neon light where you have the phase wire
- take the lamp holder, connect one of the wires to L, the other to one of the two wires (PE or N)
- if the bulb lights up - the other wire is N
- if the RCD trips - the other wire is PE

retrofood · Answer

Apparently my colleague is a technician. Are you a technician - an electrician?

elpapiotr · Answer

Welcome back.

Because there are so many ways to find the right cable or a single wire that all the above answers are correct, including the use of "bells", indicating the phase by the receiver / test tube,
that it would have to be classified and specified, depending on the situation in which the cable is.

Anonymous · Answer

Electric cables are the same. The difference is in application - application.
The PE conductor cannot be used for power supply - this is the final answer.
How to state it - find the beginning, and that's not all.
The RCD will drop as in one of the sockets we will replace N and PE. If there is no RCD, we will not even notice such an error.
Measurement - there will be very little difference in LN and L-PE voltage. Voltage drop due to the operating current of other consumers.

krzysztooof · Answer

Friend retrofood, yes I am an electrician, and in my statement I meant, of course, that after connecting the phase wire with the protective conductor, electricity will flow, but only then, because normally this wire serves only to protect against electric shock.
Thank you forum members for the idea of RCD, I had this problem in my head for a long time, and the solution is so easy!
I also wanted to emphasize that this problem does not concern me, I just asked. because I didn't know.
Greetings.

kkas12 · Answer

And we have another application for the RCD. Identification of N and PE conductors. And the fact that these veins have a mandatory color assigned to them is not important after all.

Anonymous · Answer

The moderator asked well - it does not follow from the above arguments that you are an electrician. Because they're not coming together. Only the mentally ill or the ignorant layman connects the phasic and the protective ones.

tomaszostry · Answer

Hello.

That's how I came across this post.

Is it possible to apply the meter as follows. First, I detect phases with neon lights.

Then I take the meter with a squeak.

I attach one end to the radiator and the other I touch the cable.
I am not an electrician and I only think theoretical, but if I have a trophy on PE, the meter will beep for N, then I will not drink.

Is this a good way?

Łukasz-O · Answer

And if the radiator is not connected to earth or zero, the whole theory goes to the head

tomaszostry · Answer

But if it were an idea, OK?

zbich70 · Answer

Phazota with grounding will bite. It won't be OK.

gogi20 · Answer

I am also a baker. After all, he wrote well - he could not defend himself. Only the answers were such as to put it out right away. RCDs are not everywhere (especially in installations with the same color of each wire). What's wrong here? If there is no RCD, it will be like that.

Łukasz-O · Answer

The digging up of the posts from two years ago begins. I close the topic.

Differentiating Protective Conductor from Neutral in Same-Colored Wires

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