The number of technologically new household appliances and tools is growing. Accordingly, there is a need to purchase a cable to connect to the network. It is important to know how to choose a durable, flexible and fireproof PVA wire.
PVS wire: decoding and application
It is the best option for domestic conditions, which makes it especially popular. The abbreviation indicates its following characteristics: "P" - wire, "V" - vinyl insulation; "C" - connecting. The cut is round.
There are options with PVSP marking. In this case, the veins are arranged in parallel, and their shape is oval in the section. It is often referred to as flat. The PVS-T marking can be deciphered as operation in conditions of increased dampness. PVSN wire denotes that the product is of the fifth class of flexibility. The absence of the letter "A" at the beginning indicates that the veins are copper.
It can be used in the manufacture of tools and electrical appliances, as well as in all areas of human activity:
- connection and repair of household appliances;
- arrangement of temporary electrical wiring in residential and household premises;
- as a connecting, extension cable for different needs;
- power supply for small agricultural and garden equipment;
- in production, for equipment with high energy consumption.
It is a structural element of almost all household appliances and locksmith tools.
PVA is a cable or wire
PVA is one of the most common types that can be used for networks with voltages up to 380 volts, has from two to five cores. Each core consists of thin, twisted wires, enclosed in separate insulation. For ease of installation, the insulation of the phase wires can be brown, white, red or black. Zero is colored blue or light blue. The insulation of the grounding conductor is yellow-green. The overall shell also has a wide range of colors.
There are a lot of options, they differ in the following parameters:
- The outer one has three conductors - phase, zero, ground. It is convenient for supplying power from an external transformer to an indoor distribution board.
- The inner wire is arranged in the same way. It has no protection against climatic conditions and dampness. Can be used indoors.
- Copper - high strength, has low resistance and increased electrical conductivity, corrosion resistant.
- The advantage of aluminum is the price. Aluminum oxide treatment increases service life.
You can decipher the marking of other varieties as follows:
- T - resistance to mold and mildew;
- B - armored cable;
- U - increases the temperature minimum;
- PS - self-extinguishing shell;
- G - without isolation;
- SP - power;
- T - telephone cable.
Also, the wire is divided into standard sizes according to the number of cores, weight and profile in the section.
Specifications
The main thing is the operational data, the number and cross-section of the cores. The same characteristics apply to all types:
- the maximum allowable voltage is 450 volts;
- designed for networks where the current is up to 50 Hz;
- permissible core heating up to 70 °, thermal stability - class Y;
- fire resistance class - standard;
- operating temperature from - 20 ° C to + 40 ° C.
The wire has increased mechanical strength, high resistance parameters. It is able to withstand up to 30 thousand bends.
What regulatory documents govern the use
In the manufacture of PVA, they are guided by the requirements of GOST 7399-97. The section includes basic information about the assortment, a list of tests, safety requirements. The technical standard regulates the basic mechanical and electrical threshold data. The manufacturer may change individual specific figures within the specified tolerances.
In accordance with GOST, the wire by the number of cores can have 4 versions. The cross-sectional area of the conductors varies from 0.75 to 16 mm2. Products with maximum parameters are produced only by cable factories.
According to the norms, the wire twisting 0.75-2.5 mm2 should be done in the left direction, without filler.
When working in a mobile position, the service life is 6 years. In static mode, service can last up to 10 years.
Installation features
When connected to a machine, plug and other device, the ends are exposed, the insulation is removed. According to the PUE, the conductors are connected by crimping the tip.
When laying the network outdoors, you need to take into account temperature fluctuations, humidity, the negative effects of UV rays, the risk of mechanical damage. The main requirements are strength, hygroscopicity and resistance to combustion. Outdoor installation is carried out in corrugated pipes, which are attached to a wall or other stationary objects.
PVA is not intended to be laid in the ground. In extreme cases, it can be hidden inside a double-walled pipe. When installing in a damp room, the connection rules must be observed. No twists are allowed. The best option is a connection using heat shrink tubes.
How to choose a PVS
In everyday life, a three-core wire is enough. It is selected depending on the power of the equipment that will be connected. There are many fakes on the market, so it is advisable to check the main parameters yourself. In order not to purchase a counterfeit product, you need to check the certificate of conformity.
For industrial purposes, it is important to have an earth conductor. For such electrical installations, a four-core copper cable is mainly used.
VVG cable in comparison with PVA
The VVG cable has good qualities and a relatively low price. Its purpose is networks with alternating current: voltage from 660 to 3000 V, operating voltage from 1 kW to 3.5 kW. It can have from 2 to 6 conductors, with a cross section of 1.5 - 250 mm2.
They have the same copper conductors and PVC insulation. The main difference is in the flexibility class. PVA is elastic and belongs to the 5th class. VVG cable has 1 or 2 class. The diameter of the wire and their number in the core depend on this. For example, a VVG cable of 1 class of flexibility with a cross section of 2.5 mm2 can have only one wire 1.78 mm in diameter. The same PVA will consist of 50 wires with a diameter of 0.25 mm.
The product differs in the type of profile. Veins of small diameter are round, large ones are sectorial. Another difference is the thickness of the insulating material and the shell. For the cable, the thickness of the inner layer is 0.8 mm, the outer layer is 1.5. For PVA, respectively - 0.8 and 1.1 mm.
There are different modifications of the VVG cable. Possible hidden wiring in the room. It is used for outdoor lining. An overhead or underground electrical cable needs additional protection with a corrugated hose.
Advantages and disadvantages of PVS
The main advantage is the relatively light weight, softness and flexibility of the cord.This makes it possible to lay in complex systems, structures with a steep transition radius, a large number of bends and turns.
It can be used in electrical networks for 220 and 380 volts. The wire has a standard fire resistance class. The insulation material does not ignite from an external flame and does not support combustion.
With its help, it is not recommended to carry out hidden installation, since the service life is no more than 6 years. Having a round cross-section, it is inconvenient for installation under plaster.
PVA has found wide application and is in great demand among buyers. However, for electrical wiring, it is better to choose the most suitable cable VVG, VVGng, or another analogue for this purpose.
