There are two kinds of conductors.The conductors of the first kind are metals.The conductor of the second kind include solutions: acids, salts, alkalis and bases.These conductors are called liquid electrolytes.
substances, almost non-conducting, are called insulators or insulators.These gases include, mineral oil, varnish and other solids.By the insulators used in electrical work are: porcelain, asbestos, rubber, mica, glass, plastic.Gases, including dry air, are also good insulators.However, under certain conditions, gas (including air) can conduct electric current.For example, incandescent air a good conductor of electric current.Electrical energy is transmitted over a distance by means of wires, cords and cables.One or more twisted wires form a conductive wire - wire.Wires are used to transmit electricity.
wires are divided into non-insulated (bare) and isolated.Insulated wires are rubber, cotton, PVC, or plastic protective shell.
Cord is called two or more isolated and placed a
Paving the harness room and tooling fixtures, use insulated wires and cables.They come in different brands.Each brand conditionally represent letters and numbers.Indicate the material of wire, the nature of the insulation, number of wires.The figures show the voltage at which the wire is calculated.For example, the brand APR-500 indicates that this conductor with aluminum core and a rubber insulation rated at up to 500.
brand SR twisted cord of two flexible wires.Once upon each of them consists of thin copper wires, the total cross-sectional area of 0.5-1.5 mm2.Insulation - rubber, protected by a braid of cotton yarn.The premises used for electrical wiring cables with one, two or three conductors.
Wire DWP brands do as well as cable, but the copper wire from which the twisted wire, have a cross-section of 0.5-6 mm.This wire is not so flexible.
for table lamps and other portable devices use flexible wires brand DPRG total cotton braid.Recently we began to apply the same wires in plastic insulation.
brand PR Wire has one copper, lead brand APR - an aluminum conductor.Lived covered with rubber and cotton braid is impregnated with its waterproof protivognilnym solution.Wires PR and APR may be installed in areas where a lot of moisture: in the kitchen, bathrooms and so on. P. More often in these cases, apply the wire in plastic covering px and PVG.Mark SH means - wire with vinyl chloride insulated flexible.
For mounting lighting fixtures used wire AR and PSA.They are called reinforcement.
very common flat wire marks PV - copper and APPV - with aluminum conductors and wires APP brand with aluminum conductors.APPV wires and PVC jacket isolated APW, and APN neyritovoy light- resistant rubber sheath.