Coloring in home wiringTo date, installation of an electrical cable without the use of wires in colored insulation is unthinkable. Such marking of conductors is an urgent need, since, pointing to the purpose of each wires, it helps reduce the likelihood of errors during installation and, as a result, the occurrence of short closure


  • 1 Wire classification options
  • 2 Marking of wires at alternating three-phase current
  • 3 Wire color plus (+) and minus (-) in DC networks
  • 4 Wire colors in electrical wiring
    • 4.1 Color of zero working and zero protective wires
  • 5 How to independently determine the ground, zero and phase of the wires if there is no marking?
    • 5.1 Phase Detection with Indicator Screwdriver
    • 5.2 Determination of grounding, zero and phase using a test lamp

Wire classification options

Before dealing with the decoding of markings, it is recommended to familiarize yourself with the parameters by which the wires are separated:

  1. Number lived. Depending on this parameter, the cable can be used for ensuring the operation of electric motors, for distributing the wiring in a house or apartment, for transmitting current in power networks.
  2. Current-carrying material. As a material in electrics most commonly used copper and aluminum or a combination of these metals.
  3. Insulation. Wires can be with and without insulation. Bare conductors provide communication power lines. Insulated are laid in those places where there is a likelihood of exposure to external factors in the form of wind, water, dust or snow. Plastic, rubber, lead, paper and many other materials are used as insulation.
  4. Cable section. With this indicator can determine the strength of AC or DCwhich will be held by the conductors.
  5. Other indicators. The indicators of resistance, power and voltage are very important for wiring the network and connecting various devices.

Knowing which conductors are responsible for the load, you can correctly connect to the meter, repair the wiring, connect the oxygen sensor in the car, etc.

Marking of wires at alternating three-phase current

How to determine phase, zero and grounding if not labeledLooking at the color marking, you can easily determine the ground, zero and phase. In modern electrical conductors each vein has an individual coloring. Knowing what lived for which color matches, you can easily complete the installation. If the installation was carried out with new wiring and according to modern standards and rules, then this is quite enough.

  1. Neutral or working zero blue or blue and white.
  2. Ground or protective zero is a yellow-green wire.
  3. The phase can be marked with all other colors, including:
  • turquoise;
  • Orange;
  • white;
  • pink;
  • Violet;
  • Gray;
  • red;
  • brown;
  • the black.

Having dealt with the color of the marking, you can easily determine which wire is responsible for which function. By virtue of a different work pattern, exceptions may be made by conductors suitable for switches, breakers, etc.

Wire color plus (+) and minus (-) in DC networks

In some areas in the national economy DC networks are used:

  • for operational circuits of protection and power automation in electrical substations;
  • in electrified transport;
  • in construction, industry, when storing materials.

In such networks, only two conductors are used: positive and negative tires. There is no phase or neutral conductor in them.

Marking of wires and tires for DC networks:

  • red color is used for positive charge wires;
  • blue - for tires and wires with a negative charge;
  • blue is the middle conductor.

If the DC network is created from a three-wire network (by branch), then the color of the positive conductor is the same as the positive conductor of the three-wire circuit.

Wire colors in electrical wiring

Wire marking in color at three-phase current and in DC networksThe designation of wires in color is very convenient, especially when one person makes their laying and connection, and another person will maintain and repair.

Each the color of the electrical conductor determines its purpose cable according to a certain standard, which has been changed several times since the USSR.

To date, conductors in AC electrical installations with a dead-earthed neutral and voltage up to one thousand volts have a very specific label.

Color of zero working and zero protective wires

  1. Zero operating conductors are indicated in blue.
  2. Zero protective painted in yellow-green transverse or longitudinal stripes.
  3. Combined zero protective and zero working conductor along its entire length marked in blue with yellow green stripes in joints. Maybe the other way around - the whole conductor is yellow-green, and the joints are colored blue.

This combination of colors is used only for labeling zero protective pinch conductors.

How to independently determine the ground, zero and phase of the wires if there is no marking?

Quite often such situations arise when the connection is made incomprehensibly as. Some electricians even today may use outdated wiring regulations, which is why other professionals have to search for zero and phase with a probe and mark the conductors with the desired color with electrical tape or heat shrink tubing of the desired color.

Phase Detection with Indicator Screwdriver

Wire classification optionsInside the probe is a resistor and a lamp. When the tip touches the contact screwdriver and the live conductor, the circuit closes and the lamp lights up. Resistance reduces the current to a minimum, protecting it from electric shock. Thus, it is easy to find out which phase wire is easy.

This is the most preferred option for determining the phase, especially the cost of a screwdriver is quite affordable. Its main drawback is the possibility of erroneous operation. Sometimes indicator screwdriver may react to pickup and determine the presence of voltage where it is not.

Determination of grounding, zero and phase using a test lamp

This method of definition is quite effective, but requires special care:

  • The lamp is screwed into the holder, and the wires with the insulation removed at the ends are fixed to its terminals;
  • You can also use an ordinary desk lamp with an electric plug;
  • the technology is pretty simple - lamp wires are alternately connected to conductorsthat require definition.

In this way, you can only find out which conductor has a phase. If the control lamp caught fire, then this wire has a phase. If the lamp is off, then there is no phase among the wires or there is no zero. This, too, can not be ruled out.

To determine the phase wire, you can connect one of the ends coming from the lamp to a known zero and then the lamp will light up when the second end is connected to the phase conductor. The wire that will remain and will be respectively zero.

The method of determining the phase or zero using a lamp is good for testing the wiring.

It should be remembered that when working with electrical wires requires care and caution.