Electrical equipment power 2500W, in 220V power supply working current: I = P / U = 2500/220 = 11, 4A copper wire safety current: I1 for each square millimeter 6-9A. Calculated by 6, the cross-sectional area of the copper wire: I / I1 = 11.4 / 6 = 1.9 square millimeters, so the cross-sectional area of the copper wire selection: 2.5 square millimeters.
In physics, electrical power is used to indicate how quickly electrical energy is consumed. Electric power is expressed in watts (Watt), or simply watts (Wa) symbolized as W. The magnitude of electric power is related not only to the amount of work done by the current, but also to the time taken to do the work.
Every electrical appliance has a normal working voltage value called rated voltage, electrical appliances in the rated voltage of the normal work of the power is called rated power, electrical appliances in the actual voltage of the power is called the actual power.
Absorption or issue: the ultimate purpose of a circuit is the power supply will be a certain amount of electric power to the load, the load will be converted into a certain form of energy required for the work of the load. That is, there are devices in the circuit that emit power (energy-supplying components) and devices that absorb power (energy-consuming components).