In everyday life we use many electrical appliances that require a variety of wire and cable in the choice and placement of which requires special knowledge and rules.
Choosing the cable or wire should be guided by the basic criteria? commodity purchase only from manufacturers of famous brands and proven in the field of reliability and quality.
In accommodation, the wire used mainlybrand PVA and cables brands such as VVG, NYM and VVGng. PVA is a stranded wire, with a circular cross-section copper wire. It is used to connect power tools and household appliances, gardening. wire laying at a temperature between -15o C to + 40o C Wire insulated material of PVC plastic. Lived ? Copper, flexible.
VVG applies to power cables. Its use in stationary installations for the distribution of electric power with voltage of 0.66 to 1 kV, in a temperature range from -50 to +50 degrees and humidity of 98%. VVG cables used for installation in residential and industrial premises, in dry and wet.
VVGng cord is different from the VVG that its shell is made of heat-resistant materials, so it is used at facilities with special requirements for electrical and fire safety.
Cable core VVG and VVGng made of soft copper wire of circular cross section. By increasing the cross-section of more than 16 square millimeters, it is performed live as much of the wire harness.
And finally, the brand NYM cable. Thanks to an extra layer of chalk-rubber insulation from the cable, increasing its resistance to cracking during installation in extreme conditions. External insulation is made of a flexible plastic, which leads to increased safety. Thanks to these qualities, the popularity of this cable is continuously growing.
Cable cross-section area of the electrically conductive believeveins. According to the formula? (= 3,14) xr2 calculated cross section of a circular core. The cable typically has several conductors, so the total cross section of tiles equals the sum of the cross sections of each core. To measure the diameter of the wire using a caliper and micrometer.
cable cross-section selected in view of the futureload. Note, however, that the cross section of aluminum wire should be chosen much higher, because its conductivity is 40% lower than that of copper wire. Mainly used standard types of cross-sections of 0.75 to 10 mm.
To select a cable for each load usedspecial tables, however, experienced electricians use simple wire cross-section calculation: Cable cross-section 1 mm2 withstand current 10A and power of 2.2 kW (10Ah220V = 2.2 kW).
Example: your appliance has a power of 8 kW, current 36A, respectively (8000Vt: 220 = 36A), it follows that the conductor cross-section must be 4 mm² (36A: 10A = 3.6 mm2 standard 4 mm²).