In recent years, due to the improvement of living standards and the rapid development of the dry "Waterproof Cooling Fan" industry, household appliances variety, quantity increases rapidly, many families have a variety of household appliances, so there have been a thousand circuit overload phenomenon. Household appliances, power lines from the power wires, electrical equipment, control and protection devices composed of circuit connection from one thousand. "Waterproof Cooling Fan" allowable current supply line load is determined by the material and cross-section wire, commonly used materials are copper and aluminum wire, copper wire than aluminum allows a large current through, the greater cross-section wire allows current greater. To ensure the electrical safety and performance of electrical equipment to ensure the normal, every "Waterproof Cooling Fan" should be a separate power supply socket, not a few electrical devices to share a long outlet to avoid the use of performance circuit overload and impact of electrical equipment .