电缆载流量的计算（Calculation of ampacity of cables）.docVIP

电缆载流量的计算（Calculation of ampacity of cables） Ampacity of cable: The current carrying capacity of cable is a cable line in the current transmission power when the heat, in stable condition, when the working temperature of cable conductor cable to allow long called the cable ampacity Ampacity for long time. The estimation formula of two point five multiplied by nine, to go up by a smooth number. Thirty-five by three point five, both in group minus five points. Conditions have changed and converted, high temperature ten percent off copper upgrade. Intubation root number two three four, 87 forty percent off full flow. That (1) this section formulas for various insulated wire (rubber and plastic insulated wire) ampacity (safe current) is not directly pointed out, but the section multiplied by a certain multiple to that obtained by mental arithmetic. As can be seen from table 53, the multiples decrease with the increase of the cross section. Two point five times multiplied by nine, go up to reduce a number to go, that is 2.5mm and the following sections of aluminum core insulation line, its carrying capacity is about 9 times the number of sections. For example 2.5mm lead, the ampacity is 2.5 x 9 = 22.5 (A). The relationship between the current carrying capacity and the cross sectional number of the wires from 4mm and above is along the line number, and the multiples are progressively reduced by L, i.e., 4 * 8, 6 * 7, 10 * 6, 16 * 5, 25 * 4. Thirty-five multiplied by three point five, both in group minus five points, said 35mm, the lead carrying capacity is 3.5 times the cross section number, that is, 35 x 3.5 = 122.5 (A). From 50mm and above, the relationship between the carrying capacity and the number of sections becomes two, the two line numbers are in one group, and the multiples are reduced by 0.5 sequentially. That is to say, the carrying capacity of 50 and 70mm wires is 3 times of the cross section; the carrying capacity of 95 and 120mm wires is 2.5 times of the cro