电线平方数与电器功率(国外英文资料).docVIP

电线平方数与电器功率(国外英文资料) [quoted] wire squares and electrical power 2011-03-26 12:21:45|: the world famous subscription | electromechanical classification This article reprinted from the square of the number of wires and appliances Dachen power I. copper current carrying capacity of copper conductor The wire is safe carrying capacity according to the allowed core temperature, cooling conditions and installation conditions to determine the The general safety of copper wire flow 5~8A/mm2, aluminum wire, safe carrying capacity is 3~5A/mm2. Such as: 2.5 mm2 BVV copper wire safe carrying capacity of the recommended value of 2.5 * 8A/mm2=20A 4 mm2BVV copper wire safe carrying capacity of the recommended value of 4 * 8A/mm2=32A Two. Calculate the sectional area of copper conductor The recommended safe carrying capacity by using copper wire to calculate the value of 5~8A/mm2, the selected copper wire cross-sectional area of S on the range: S=, I / (5~8) =0.125, I, ~0.2, I (mm2) S----- copper conductor cross-sectional area (mm2) I----- load current (A) Three. Power calculation The general load (can also be used as electric appliances, refrigerators, etc.) are divided into two types, one type is a resistive load, inductive load. The formulas for calculating resistive load: P=UI The formulas for calculating the load of the fluorescent lamp: P=UIcos, the fluorescent lamp load power factor cos =0.5. Different inductive load power factor is different, household appliances can be unified computing power factor cos phi 0.8. That is to say, if a household uses all appliances with a total power of 6000 watts, then the maximum current is I=P/Ucos =6000/220*0.8=34 (A) However, under normal circumstances, the home appliances can not be used at the same time, so with a common factor, the common factor is generally 0.5. So, the calculations above should be rewritten as The I=P* utility coefficient /Ucos phi =6000*0.5/220*0.8=17 (A) That is to say, the total current value of this family is 17A.