At repair of electric devices and networks often it is required to know wiring parameters correctly to calculate costs of preparation of communications. One of such characteristics is the section of electric cable. The cable consists of several insulated wires closed by hermetic cover. For determination of section of cable you will need some simple devices and tools.
It is required to you
- Caliper, ruler, pencil (rod)
Instruction
1. Determine necessary parameters of current network in which it is supposed to use cable (in particular, current intensity). When laying cable or wiring from several wires in pipes the value of permissible current has to be reduced by 15-20% as they will heat each other. It is easy to calculate the section of one vein of S, knowing its diameter of D. The simple formula is for this purpose used: S = 0.785xDxD.
2. For measurement of diameter of wire use caliper. It gives very insignificant measurement error which for calculations can be neglected (no more than 0.1 mm). Capture wire caliper sponges. Slightly press sponge not to cause mechanical damages of wire. Record sponges the screw. On instrument scale you will see the value corresponding to core diameter, measured to within the tenth shares of millimeter.
3. In the absence of caliper other method is applied. Clean part of vein of wire from isolation. Reel up vein on pencil, thick nail, the screw-driver or any other suitable rod, trying to do winding strictly round to round as it is possible more densely. It is required to reel up on rod of 10-20 rounds of vein (the more rounds, the measurement accuracy is higher). Strong squeeze rounds and measure length of the received spiral by normal ruler. Then separate its length into number of rounds – you receive required core diameter.
4. For determination of section of the multi-conductor cable measure diameter of one vein, calculate its section on formula, and then increase its value by number of veins in wire. Section of veins at small currents, in particular in screw terminal clamps, is defined by mechanical strength of the conductor. Section of cable cores should not be less than 2 sq. mm for aluminum vein and 1 sq. mm for copper vein.
5. If you want to feel confident and it is safe in the dwelling, surely check whether there corresponds the section of electric cable to the maximum physical activity and current of protective safety locks or the time cut-out.