Quite important is the installation of electrical communications inside the building. Electrical wires must ensure the supply of electricity of adequate quality, perform in full volume permanently assigned functions and meet the rules of fire safety. To ensure accurate and safe operation, the company should seriousness Treat the choice of electrical wires.
Buy the necessary electrical wire for the installation of internal wiring is easy. The assertion that in this matter the right choice can only be made by specialists, is wrong. To pick up the wires necessary for ensuring the necessary characteristic, under force to everyone. It is necessary to determine what will be included in the new grid, what is the total capacity of the proposed devices. Further knowledge in physics and reference books will help.
- 1 Electrical cable structure
- 2 Cable marking
- 3 Internal wiring cables
4 Electrical cables for external wiring
- 4.1 Principles of wiring in the street
Electrical cable structure
The cores are the main component of any electrical cable. According to them, the transfer of electricity. They are separated by dielectric insulation, and are also in a single shell.
There are two types of conductors for electrical wires:
- single wire;
- stranded, containing many individual veins.
Many people incorrectly assume that single-wire and single-conductor electrical cables are similar. In fact, single core wires have only one core. Here it is, in your turn, can be both single-wire and multi-wire.
Materials for the production of live conductors are copper and aluminum. Aluminum wire is cheaper than copper, but its conductivity is lower. That is, with the same cross-section of copper cable can withstand a large load. The disadvantage of copper is destructible in air.
When working with materials from aluminum and copper, one should take into account the fact that their compound rapidly oxidizes. This means a quick breakdown of contact between them. Such a situation may lead to a short circuit in the wiring area. Therefore, the connection through twisting in this case is excluded, the wires are connected using a terminal clamp. The ideal option would be to use wires of the same grade on all parts of the work performed.
Cables sheathed. Insulating layer is made:
- from rubber;
- from polyethylene;
- from PVC plastic.
All these materials have high electrical insulating features. Because of this, they are allowed to apply in networks of different voltages in the range of 500 watts.
Any cable used for installation inside the house and apartment includes at least 2 insulating layers: the first protects the bundled internal cores, the second surrounds only 1 core.
First you need to determine the difference between the electric cable and the cord.
- A cord is a wire that consists of flexible conductors covered with a protective cover.
- Insulated wires are twisted together by cable. prisoners into the shell.
To determine the selection of the optimal cable, it is necessary to carefully examine the labeling of the product. The cable must be shown: brand, name of the manufacturer and compliance with GOST or T. W. The size of the section and the name are applied along the entire length of the cable at regular intervals.
The marking of each cable is shown with 3 characters. 1st the number of the numerical designation indicates the number of cores, the second - the cross section of any of them, the third - the voltage. Other numbers indicate the degree of elasticity of the wire.
The first letter sets the type of raw material used to form the top insulation coating. If you have a product marked with the first letter “A”, it has aluminum conductors, in the absence of letters there are threads made of copper.
The second letter shows the type of cable:
- "K" - control;
- "P" - flat;
- "M" - assembly;
- "W" or "U" - installation;
- "Mg" - installation with a flexible core.
The third letter refers to the material used for internal insulation..
- "P" - polyethylene insulation;
- "B" or "BP" - rubber insulation;
- "PV" - vulcanizing polymer;
- "PS" - self-extinguishing polymer;
- "C" - lead sheath.
Rubber insulation can be protected with a jade "H" coating or a polyvinyl chloride "B".
Internal wiring cables
The most famous electrical wiring for internal wiring is VVG (single wire core). It can be found both flat and round. He is such brands:
- VVGng - non-flammable, does not ignite when rolled into knots.
- VVGng-LS - non-flammable, does not smoke.
The properties of NYM (single-wire core) are similar to VVGng, but there is a micro-filler among the cores to make the cable rounded.
PVA (multiwire vein) is always round. It differs from previous cable types in greater elasticity.
ШВВП (multi-wire core) is flat, with the largest cross-section of 0.75 square millimeters. Due to the small cross-section, the cable is used only for connecting home devices of low power (light, TV, PC). He is called the telephone. In order to connect washing machines, electric plates SHVVP not used.
Everything given cable types may be used for hidden and open wiring. The properties of the conductive wires in all these types are almost equal. Wire for mounting hidden wiring is selected for the convenience of working with him, hard either elastic.
Elastic - SHVVP and PVA. Hard - VVG and NYM. In case the conversation going on open wiring, you need to look at the color of the cable. For example, VVG always dark tones; NYM - grayish; PVA - white, orange, rarely - black; Ball screw the black. If not succeeds choose the wire of the required tone, it can be wired in the corrugation
Now analyze, What does the color of the wire in the wiring mean?
- (N) Zero — blue;
- (PE) Safety Zero - yellow greenish;
- (Pen) Combined zero - blue with yellow greenish stripes;
- (L) Phase - brown, white, the black, gray, red and a number of colors;
Electrical cables for external wiring
The main criterion when buying a cable for wiring on the street is confidence in its safety and the ability to withstand negative external factors. The main requirements for this product - resistance to burning, reliability and moisture resistance.
To the most common species need to rank:
CIP - power wire for the street, which can carry out work up to 1 kV. This is an aluminum wire consisting of several wires with individual insulation. It has subspecies (CIP -1, 2, 3), and it is manufactured in several countries. The main feature is considered the black insulation color. The use of this cable provides significant security for air mounting and reduces costs in operation. An additional advantage is the compactness that gives the ability to apply the wire, including in the circumstances of lack of space.
AVBBSHV produced from aluminum wires under armored insulation. One type of cable is VBbShv - with reddish yellow by wires. A distinctive feature is the probability of laying in the ground without the use of additional insulation and resistance to mechanical stress. Basic properties:
- The presence of metal foil in the plating.
- Wires of different colors for the purpose of comfortable dialing and connection.
- The outer layer is made in black coloring.
- Moisture resistance and independence from temperature drops.
- Shelf life - 30 years.
Such wires are more tough due to the use of armor, which may cause some inconvenience during installation.
NYY is a wire that stands out for its versatility and durability in its use. Sometimes copper and aluminum. This product is more used when laying in the ground or air, as well as for the purpose of connecting electrical equipment in the premises. Basic properties:
- Moisture and flame retardant.
- Consistency with international standards.
- Multicolor insulated wires.
- Comfortable working with him in an open space.
- PVC outer layer black colors.
- Climate resistance.
- Service life is 30 years.
Such wire is made at numerous enterprises, which is caused by its multifunctionality and durability. The main competitor of the product is the wire Vbbshv mentioned earlier.
NYM is a highly reliable wire that is often used in industry and is present when wiring is made outdoors. Its distinguishing feature is multilateral application and ability to operate in different circumstances. Properties:
- Satisfies the generally accepted standards of the association of electrical engineers in Germany.
- The ability to maintain their properties at different temperatures.
- Non-absorbent, durable, that gives the ability to lay it in concrete or under plaster.
- The cross section is round, the tone is gray.
- Does not ignite.
When wiring outdoors using NYM, it is recommended that it be protected from sunlight. Similar products are manufactured at numerous Russian and European enterprises. Some manufacturers produce wire. according to the personal specifications, however, such products have the lowest cost and, in accordance with this, lower quality. The use of similar cables for the installation of outdoor wiring is not recommended.
Principles of wiring in the street
Selecting an electrical wire for outdoor wiring on the street, it is important to take into account the characteristic features of this operation. There are several aspects that affect security and distance to residential buildings. Thus, the distance from the cable to the porch should be no less than 250 cm, and to the balcony or window - 100 and 150 cm, respectively. If the scheme is performed vertically, the distance from the ground plane should be 275 cm, to the balcony or opening Windows - 100 and 75 cm, respectively.
When the cable is run along the wall, it is important not to break a few rules:
- If separate wires are used, use plastic or metal pipes.
- Connection of wires through the terminal connectors (twists are prohibited).
- Suspension of cables between houses is allowed using a cable and a corrugated hose.
- Wire connections must be performed exclusively in impenetrable junction boxes.
- Laying the wires in the roof is prohibited.
In the course of outdoor wiring, there are several other important aspects to consider. So, the line of an individual building is able to connect to the power supply. three either single-phase voltage (380 or 220 V). In the case of aerial installation, the use of SIP-4 cable is recommended.
Armored cables of brands VBShv or AVBShv are more suitable for laying under ground Their distinguishing feature is moisture resistance and durability. Internal wiring is performed with a larger cross-section aluminum cable to reduce the financing of installation work.
When laying the cable outdoors, it is necessary to provide a method of installation. We should not forget that your peace of mind, security and, in some cases, life also depend on the accuracy of the selection of cable products and compliance with the standards of electrical installation codes.