Run home improvement power is impossible without the involvement of an electric cable.
What types of products offers a modern market and a wire used for wiring in the house, take a closer look.
The content of the article:
- What makes electrical cables?
- Variety of electric wires
- View # 1 - cable VVG
- View # 2 - cable NYM
- View # 3 - wire SPAP
- View # 4 - armored cable VBbShv
- Criteria for selection of competent
- How to calculate the wire size?
- Useful videos on the topic
What makes electrical cables?
The basic elements of any electrical conductor of the cable protrude - elements for passing an electric current isolated from each other inside the casing and enclosed in a common sheath. They are abbreviated as TPG.
Conductors for electric power transmission are of two types:
- single-wire solid;
- strandedConsisting of a large number of thin filaments.
Some mistakenly believe that single-wire core and single-core cables - the notion of identity. In fact, single-core products can have only one core, which, in turn, can be performed either as single stranded.
The basis of copper or aluminum may act as conductors for manufacturing conductive. If we compare these metals, the aluminum, although it is cheaper, but loses that has a lower level of electrical conductivity.
This means that with an equal cross section copper conductor is able to pass more current. The only "minus" copper is the time that it is quickly destroyed in the air.
By working with these materials, it is necessary to take into account that the aluminum and copper form a galvanic couple. This connection is quickly destroyed. Therefore, they can communicate with each other only by installing terminal.
When docking an produce by stranding, this place is rapidly oxidized, leading to rupture of contacts, which resulted in the closure of the line may occur. Ideally for all lines in the apartment have to choose the same type of wire.
Cables for electrical signals equip shell. The insulating layer may be made of:
- rubber;
- polyethylene;
- PVC compound.
Each of these materials is characterized by high electrical performance. Because of this they can be used in networks of different voltage grade within 500 watts.
Any cable used for intrahouse and the residential wiring, has at least two insulating layers: the first protects bunched inner conductor, the second conductor encircles only one.
Variety of electric wires
There are several classifications, which are guided in choosing the master cable to the wiring in the house.
The first ground on which the cables are divided - number of cores. Operating parameters mono- and multifilamentary articles detailed in the table below.
Below are the four most popular types of cables used in the regeneration of postings inside apartment.
View # 1 - cable VVG
At arrangement of the wiring inside apartment, which provides for the installation of the junction box, used cable VVG.
It is used for the transmission of electric current at an operating voltage in the range of 1000 V. Number of cores in such articles may range from one to five.
Among the indisputable advantages VVG products is attributed a wide temperature operating range. It can be safely used at temperatures from -50 ° C to +50 ° C. Wire famous high tensile strength and ability to withstand moisture to 98%.
The product of this type can have one of three designations:
- «P"- indicates the type of flat cross-section;
- «s"- indicates that between the insulation and the outer sheath TPG rubber composition is PVC or tows;
- «ng"- indicates that the insulation is not flame retardant.
In all kinds of cables VVG, except those that are designated "h" between the outer shell and the insulating layer of living space is not filled.
For domestic use, use a cable cross-section of 1.5 mm2, the regeneration of a private house in the product 6 mm2. The magnitude of the bending radius of the product determined by multiplying the cross section at 10.
View # 2 - cable NYM
NYM - another quality power cable designed for power and lighting networks with voltage up to 660V. Stranded conductive core products are made of copper.
Number of conductors NYM cable can range in area from one to five. Minimum cross-sectional parameters presented for sale products is 1.5 mm2, the maximum - 16 mm2.
The magnitude of the bending radius corresponds to four diameters of the cross section.
The cable is double insulated:
- the outer shell is made of polyvinyl chloride;
- the inner sheath is made of a noncombustible PVC.
Inner space between filled with insulating interlayers excipient which is rubber coated. This solution increases the strength of the product and makes it more resistant to high temperatures.
Therefore NYM cable is one of moisture and heat-resistant products. Its working temperature ranges from -40 ° C to +70 ° C.
The only drawback NYM cable is vulnerable to ultraviolet rays. For this reason, when used in an open area, which is exposed to direct rays, it is recommended to cover.
When compared NYM VVG analog cable, then the former is more preferable in terms of operational parameters.
But with a limited budget, you can always save, utilizing only NYM cable for connecting indoor and residential boards with heights, and on the sites lay cable VVG.
View # 3 - wire SPAP
Often used by low cost analog for wiring - flat wire SPAP. It is a two- or three-wire product 1.5-6 mm2 cross section. Each core flat wire made of copper and is the single-wire.
The cable also has a double insulation:
- prizvedena outer sheath of flexible PVC;
- inner sheath is made of PVC.
In terms of quality of such a wire is not the best option. Furthermore, as practice shows, the conductor insulation is very vulnerable to fluctuations in temperature and quickly destroyed when heated.
View # 4 - armored cable VBbShv
At arrangement of the lighting system adjacent to the home territory is the best fit armored force VBbShv cable.
It is designed for operation under the rated AC voltage, which varies within the range from 660 to 1000 V.
Moisture-resistant product is convenient to lay in the ground, in the w / w pipes and ripple outdoors provided that a supplementary protection against direct light rays.
Conductors made of copper products. The number of threads can vary from one to five, each of which may consist of one or more of the wires.
The cross section VBbShv products ranges from 1.5 mm2 to 240 mm2. As the inner insulation and the outer shell is used polyvinyl chloride.
Criteria for selection of competent
The key to the smooth operation of the home line is the quality of the electrical system components. And because at the stage of acquiring one of the key objectives - to choose good quality cable.
To orient the choice of a suitable cable, you need to examine the product label carefully. The cable should be specified: a brand name of the manufacturer and the conformity with GOST or specifications.
The cross section of the cable and the brand should be repeated at regular intervals over the entire length of the outer sheath of the product.
Marking of any electric cable is represented by three numbers and letters.
The first digit specifies the numerical designation number of cores, the second digit - sectional area of each of them, the third - rated voltage. The remaining digits indicate the class of the cord flexibility.
The first letter specifies the type of material involved in creating top braid insulation.
The second letter indicates the type of wire:
- «TO"- check;
- «P"- flat;
- «M"- mounting;
- «W" or "In"- installation;
- «mg"- mounting with flexible living.
Marking the third letter identifies a material suitable veins for internal insulation.
Variants of its designation and decryption:
- «P"- insulation made of polyethylene;
- «AT" or "BP"- sheath is made of rubber;
- «ns"- used vulcanizing polyethylene;
- «ps"- used in self-extinguishing polyethylene;
- «FROM"- the outer sheath is made of lead;
Rubber seal may be protected nayritovoy shell "H"Or PVC"AT».
The following letter indicates the type of cable "NG"- non-combustible and fire resistant."B"- armored,"LS"- it does not emit smoke during melting. Products with an armored shell is used where there is a possibility of mechanical damage.
The presence of the marking of the letter "E"Reports that the filler is present between the conductors. the combination of letters "OJ"It shows that this solid conductor.
How to calculate the wire size?
sectional area lived standardized. Their values are chosen with a focus on current, material of manufacture of cores and laying conditions. After the operation of the cable at the limit of its possibilities wires will heat up to a few tens of degrees.
And if one tray is laid Several such cables, then heated at a mutual products allowable current value drops to 30%.
Calculation made by the following formula P / V.
Where:
- R - power devices, the parameters of which are given in the technical documentation;
- V - mains voltage of 220 V.
sectional area measured in square millimeters. Thus, a "square" aluminum wire is able to pass through itself from 4 to 6 amperes. At a copper counterpart, this parameter reaches 10 amps.
For example for power appliance to 4 kilowatts using this formula becomes equal amperage 18.18 A = 4000 W / 200V. To power up such a device is required to lay the wiring with copper threads cross section of 1.8 mm2.
As better safety net value obtained further multiplied by 1.5. Therefore, the most ideal for powering such a power device - copper wire 2 mm2.
If we consider the installation option aluminum analog, the required cord, the thickness of which is greater than 2.5 times.
Simplify the task of calculation of parameters will help the table below.
The important point! Projecting concealed wiring, data from the table should be multiplied by a factor 0.8.
In the open mounting method in the same private house, in any case, reliability is better to use a wire cross section of 4 mm2 and above favoring the products with high mechanical strength.
In terms of cross-sectional plane assembly cable to enter the house should be one level higher than that required to service the most installed appliances.
To save money, a wire can only apply for entry into the house and connecting to the terminal block, and a line of machines to withdraw the desired section.
Useful videos on the topic
Before selecting and practical application by the best once again to recall the theory by looking useful video clips.
How to choose the right cable:
Tip Wizard, which wire for the house is better:
Price range from electrical fairly widely available. But do not skimp on this issue. Dropped price may indicate that low quality materials were used in the manufacture of the cable or wire products it has a cross section less than the stated.
Buying products of Chinese manufacturers, we are prepared for the fact that in an effort to save instead of copper conductors, many of them involve copper-clad aluminum wire. Outwardly, they practically do not differ from the copper analogs, and differ only performance.
