Colors of N, PE, PEN Conductors: Comparing Blue, Yellow-Green, Yellow & Green in Technical College

I'm still studying, I'm in the second grade of electrical technical college.
During the power engineering lessons, the teacher asked us about the colors of the cables, N and PE to be exact, we answer:
N - blue
PE - yellow-green
And he nodded and says this:
N - yellow
PE - green
PEN - yellow-green
I have never seen a green wire before, and a yellow one, I think, but with some DC installation.
Can someone explain it logically to me? because I don't understand it.

"Line conductor (L), also known as the phase conductor, an electric conductor during normal operation under phase voltage and used to transmit electricity in the power grid. In a three-phase network, line conductors are designated L1, L2, L3, respectively. Line conductors are also line conductors live and isolated from the supporting structure by insulators Insulation color: red or black or brown.
Neutral conductor (N) An electrical conductor connected to the neutral point of a power grid that can be used to transmit electricity. Popularly known as "zero working". The color of the insulation is always blue (light).
Protective conductor (PE) - electrical conductor for protection against electric shock. It can be a grounding conductor (connecting the main grounding terminal with the grounding electrode) or equipotential bonding (ensuring equalization of electrical potentials of various live parts). Two-color insulation - yellow-green (always).
Protective-neutral conductor (PEN) An electrical conductor that combines the functions of the neutral conductor N and the protective conductor PE. Two-color insulation - yellow-green. Additionally, a blue tip is installed during assembly.
The neutral conductor is an incorrect and obsolete concept, coming from the times when the neutral (N) and protective (PE) conductors were not distinguished, but apart from the phase conductors, there was only a grounded neutral conductor. The neutral conductor has been replaced by N and PE or PEN conductors, depending on their function. "Wikipedia

The teacher is raving. I have been doing the installation for several years and I have never experienced anything like this before.

Tell me more, buddy power engineering what, according to the regulations, should be the percentage of yellow and green in PE.

I found such a standard but it is probably newer.

PN-90 / E-05023: 1990

Identification of electric cables by colors or numbers.

3. Marking with colors.

NOTE - Examples of marking methods are given in Annex A.

3.1. Use of a one-color marking.

3.1.1. General provisions.

The following colors may be used in the markings: black, brown, red, orange, yellow, green, blue (including light blue), purple, gray, white, pink, turquoise.

NOTE - The letter code of the colors is given in PN-90 / E-05029.

For safety reasons, a single yellow and a single green should not be used in cases where there is a possibility of confusion with the two-color green-yellow marking (see 3.2). In this case, it is recommended to use the following three colors: light blue, black and brown.

It is recommended to use color markings along the entire length of the cable, either with colored insulation or colored markers. It is allowed to use color markings only in accessible and visible places.

3.1.2. Use of a light blue color.

The light blue color is for the neutral or center conductor.

If there is a neutral or center conductor in the electrical circuit that is to be color-coded, light blue should be used for this purpose. Light blue should not be used to mark other conductors where there is a possibility of confusion.

In a multi-core cable where there is no neutral or center conductor, light blue can be used to mark any conductor except the protective conductor (conductor).

If color coding is used, bare wires, used as neutral or middle wires, should be marked with a light blue color along their entire length or in the form of 15-100 mm wide strips placed at specified distances from each other or in all visible and accessible places.

NOTE 1 - PN-84 / E-08107 prescribes the use of light blue to mark terminals, terminal boxes, plugs and sockets in intrinsically safe circuits.

NOTE 2 - In the USA and Canada, white and equivalent to light blue are used to mark the neutral and center conductors.

3.2. Use of a two-color sign.

3.2.1. General provisions.

The marking using the color combinations given in 3.1 may be used provided there is no possibility of confusion.

The colors yellow and green should not be used in combinations other than in a two-color green-yellow combination.

3.2.2. Use of a green-yellow color.

The two-color green-yellow combination should only be used for marking and identifying the protective conductor.

NOTE 1 - The protective-neutral conductor (PEN) should be green-yellow with light blue at the ends, so that all of the above-mentioned colors are visible simultaneously. It is allowed for the PEN conductor to be marked with a light blue color, and green-yellow at its ends, so that all the above-mentioned colors are visible simultaneously (the last method is not recommended).

Bare conductors used as protective conductors should be marked alternately in yellow and green, in the form of stripes of equal width15-100 mm, touching each other either along the entire length of the cable or in all accessible and visible places. If adhesive tape is used, only the two-color green-yellow tape should be used.

In the case of insulated conductors, a two-color green-yellow combination should be made so that in each 15 mm long section, one color covers at least 30% of the surface, but not more than 70% of the conductor surface, and the other color - the rest.

NOTE 2 - If the protective conductor can be easily identified by its shape, construction or location, eg coaxial conductor, it is not necessary to color-mark the entire length; it is only required to mark the cable ends and accessible parts with clear boundary symbols or a two-color green-yellow combination.

NOTE 3 - In the USA and Canada, green is used to mark the protective conductor as equivalent to the two-color green-yellow combination.

NOTE 4 - If a conductor with a neutral insulation color is used as a PE or PEN conductor, its ends should be marked with a green-yellow color.

remik_l wrote:

In the case of insulated conductors, a two-color green-yellow combination should be made so that in each 15 mm long section, one color covers at least 30% of the surface, but not more than 70% of the conductor surface, and the other color the rest.

As a colleague wrote.

More information is specified in the EN 60464 standard

But you didn't, buddy remik_l which 70 and which 30%

By the way, I invite you to read PN-EN 60446: 2004 which was later superseded by 2008 to enter 2010 and will end in 2011 (so far).

My fellow energetic, your EN 60464 is Electrical insulation varnishes - Part 1: Definitions and general requirements .

It seems to me that the schoolteacher only made a joke, and my colleague the author took it to heart.

Apparently your teacher has no idea about electrical engineering. I have doubts about the "power" user who wrote that the phase conductor (L) may have a red color, it may have been in the past, but now if it is a three-phase installation, the color of the phase conductors (L) is as follows: gray, black, brown. the neutral (N) color is light blue and the protective conductor is yellow-green

technik.el wrote:

but now if it is a three-phase installation, the color of the phase wires (L) is as follows: gray, black, brown.

It seems to me that the standard says something completely different, but since my colleague first questioned the words of one of the predecessors, I am waiting for (current) standards / studies supporting your theory. The fact that such colors are usually used and the fact that they have become so adopted does not mean that it has to be so.

please link with the standard http://www.protekol.com/artykuly/Znakowanie.pdf

The sentence starts with a capital letter. Please follow the rules of the correct Polish language and the correct spelling of units, symbols and technical names. [retrofood]

Hello.
The standards seem to apply to wires and cables used for installation in buildings. In the machine wiring, control cables of one black color with a numerical description are used, it can also be used with one yellow-green wire. Cables by Bitner.
Greetings.

"brown and black insulation
or gray.
In some applications it is allowed
the use of other colors. "

A quote from the above study.

There are exactly different colors of the phase conductors, but you know the neutral conductor (N) should always be light blue, and the protective conductor (PE) should always be yellow-green. brown or black.


Added after 3 [minutes]:

energetyka wrote:

"Line conductor (L), also known as the phase conductor, an electric conductor during normal operation under phase voltage and used to transmit electricity in the power grid. In a three-phase network, line conductors are designated L1, L2, L3, respectively. Line conductors are also line conductors live and isolated from the supporting structure by insulators Insulation color: red or black or brown.

You wrote that in three-phase networks the wires are marked in red when I tell you that now it is not like I wrote above, and in general, overhead lines are not insulated and have no colors, they are made of aluminum because it is more profitable and the line insulator is overhead is air itself.

technik.el wrote:

and by the way, the overhead lines are not insulated and have no colors, they are made of aluminum because it is more profitable and the insulator of the overhead line is air itself.

Overhead lines not insulated? It's weird
I do not know the exact parameters of this cable, but my colleagues from "PSE" call it braided. The newly modernized 0.4kV overhead lines are made of this cable.

If a colleague previously talked about the colors used in flats, he should know that red can be found in the socket from the lighting switch

energetyka wrote:

Overhead lines not insulated? It's weird
I do not know the exact parameters of this cable, but my colleagues from "PSE" call it braided. The newly modernized 0.4kV overhead lines are made of this cable.

You probably mean AsXSn single insulated cable.