Electrical work is a rather complicated matter, which is best left to a specialist in this field. However, if it is necessary to purchase cords, wires and various cables for installation, it is necessary to understand their marking. An indication of the alphanumeric code on the insulation of products is the marking of the wires.
Currently, each manufacturer designates their products with codes so that any consumer, looking at him, can understand what the product is made of, what are the rated withstand voltage, the type of cross-section, as well as its design features and type of insulation.
To comply with these parameters, all factories and enterprises engaged in the manufacture of electrical products are required to use the international standard - GOST. Wire marking also allows you to effortlessly determine the location of the phase, zero, and in some cases, ground. Consider the main electrical products on the market.
Cables
Electrical cables are of several types depending on the purpose of use. They may also consist of copper or aluminum strands, which are bundled together under one or different winding materials ofplastic or PVC. Also sometimes there is an additional protective sheath made of steel tape.
Depending on the application, the color coding of the wires may also be different. So, they distinguish:
- RF cables that transmit radio and video signals.
- Control for signal transmission to certain devices.
- Power cables are used in lighting fixtures to transmit electricity. Can be used in both internal and external wiring.
- Cables capable of conducting current of different frequencies are used to transmit communication.
- In automation systems, control cables are used, which are copper conductors under a protective screen that removes interference and prevents mechanical damage.
Wires
A product formed from several wires or only one is called a wire. In most cases, the winding is plastic, less often wire, but there are also no insulation at all.
Currently, more preference is given to wires, the cores of which are made of copper or aluminum. Such products are used not only in electrical work, but also as windings for electric motors.
Aluminum wires are of low cost, however, the impossibility of connecting them with others, for example, copper, is considered a huge disadvantage. Copper products withstand loads well, but in the open air they quickly oxidize andare costly.
The marking of electrical wires also depends on their purpose. Installation and power are used both inside and outside the premises. Mounting, in turn, are used in the collection of electrical circuits in switchboards or radio equipment.
Cords
The cord is a few strands with a small cross section, which consist of many wires intertwined. Most often, this electrical product is represented by stranded cords, the winding of which is non-metallic.
The main use of cords is for connecting to the network of industrial and household appliances.
Letter marks
Any electrical product must be marked in accordance with GOSTs. The first letter means the material from which the core is made. If it is copper, the letter is not assigned, if it is aluminum, then it is marked with the letter “A”.
Deciphering the marking of the cable and wire with the second letter characterizes the type or material of insulation. It, depending on the type of wire, can be written as “P”, “M”, “MG”, “K”, “U”, which corresponds to a flat, mounting, mounting with flexible conductors, control and installation type of wire. The installation may also be marked as "P" or "Sh".
The next, third letter, means the material of the winding of the product:
- "K" - kapron;
- "C" - fiberglass;
- "VR" or "P" - PVC;
- "Ф" - metal;
- "E" - shielded;
- "P" -rubber;
- "ME" - enamelled;
- "T" - winding with supporting torso;
- "HP" or "N" - Nairite;
- "L" - lacquered;
- "G" - winding with a flexible core;
- "O" and "W" - polyamide silk as a braid or insulation.
Wire marking can also have a fourth letter, which characterizes the design features of an electrical product:
- "K" - the wire is armored with round wires;
- "A" - asph alt wire;
- "T" - the product is used for conducting in pipes;
- "B" - armored with ribbons;
- "O" - the presence of a protective braid;
- "G" - for the wire - flexible, and for the cable - without protection.
Digital markings
The marking of electrical wires by the first digit indicates the number of cores, if it is absent, the conductor has only one core. The second and third digits mean the wire section in square millimeters and the rated withstand voltage of the network.
Grounding
Most of the color marking of wires is designed to facilitate electrical work and the safety of its implementation.
According to the electrical installation rule, the insulation of the ground conductor must be green-yellow. In some cases, the color may be exclusively green or only yellow.
For grounding, the wire color marking is applied either inlongitudinal or transverse direction. On electrical circuits, "ground" is usually denoted by the letters "PE", which is also sometimes called zero protection.
Zero
Zero working contact does not carry a voltage charge, but is only a conductor. Color marking of wires should be bluish or blue. On the electrical circuit, zero is usually denoted as "N".
Phase
The phase wire is always energized if it is connected to the network. Phase wire color marking can be made in many colors - brown, black, turquoise, purple, gray and others. But most often the phase conductors are white or black.
PEN conductor
In any residential building or premises, it is always necessary to ground or neutralize electrical wiring. At present, it is important to carry out a TN-C grounding system, which includes the combination of ground and neutral wires. The color marking of wires combined in this system will change from yellow-green to blue.
First you need to divide the conductor into two tires - PE and N, which are subsequently interconnected by a jumper in the middle or two at the edges. Then re-ground the PE bus and check the resistance.
How to identify ground, neutral and phase?
Sometimes when repairing or updating electrical wiring, it is necessary to determine which wire means what. But it happens that the marking of wires by color is not an ally in this, because due to the long termoperation or in the event of a short circuit, this is not possible.
This task can be de alt with using an indicator screwdriver, popularly called a "control". This method is suitable for a single-phase network, without a ground wire. First you need to turn off the electricity supply, separate both conductors to the sides and turn on the electrical panel again. After that, bring the indicator screwdriver to one of the wires. If the light on the "control" lights up, respectively, this wire will be the phase, and the remaining core will be zero.
If the wiring is three-wire, you can use a multimeter to determine each of the wires. This device has two wires. First you need to set it to a rated voltage of over 220 volts. Then fix one of the wires of the multimeter on contact with the phase, and determine the ground or neutral with the other. If a ground wire is found with the second wire, the readings on the device will drop slightly below 220, and if zero, then the voltage will shift to 220 volts.
The third method for identifying wires can be used if there is neither a screwdriver nor a multimeter at hand. The marking of the wires can help with this, which in any situation for the isolation of zero will be marked in blue and blue colors. The other two contacts will be harder to identify.
If one of the contacts is colored and the other is white or black, then most likely the color will be the phase. According to the old standards, the ground wire was indicated in black and white.
Also, according to installation ruleselectrical equipment, the ground wire is marked in white.
Marking in DC circuit
The marking of wires in the DC voltage network has a red insulation color for plus, and black for minus. If the network is three-phase, then each phase will have its own specific color: red, yellow and green. Zero and ground, as usual, will be blue and yellow-green.
If a 380 Volt cable is inserted, the phase wires will correspond to black, white and red insulation, and the color of the neutral and earth will remain unchanged, as is the case with a 220 Volt network.
Self-designation of wires
Sometimes, for lack of a suitable color, you can independently change the color of the same wire used for zero, phase and ground. In this case, decoding the wire markings will be very helpful.
You can make small marks on the wires, which can be very useful in the future. You can also use colored tape and wrap the wires according to the markings.
Today, cambric, which are colored plastic tubes capable of heat shrinkage, are in great demand. In the case of using busbars, it is also necessary to mark the ends of the conductors.
