Classification Of Copper Magnet Wire

  • The copper magnet wire with a smaller diameter usually has a circular cross-section. This kind of wire is used for things like electric guitar pickups. The cross-section of the thicker magnet wire is usually square, rectangle or hexagon (with rounded corners), the packaging efficiency is higher, and the structural stability and thermal conductivity between adjacent turns are higher.

    Like other wires, magnet wires are classified by diameter (AWG number, SWG or mm) or area (square mm), temperature class, and insulation class. The breakdown voltage depends on the thickness of the cover layer and can be divided into three types: level 1, level 2, and level 3. The higher the grade, the thicker the insulating layer, and the higher the breakdown voltage.

    The temperature classification indicates that it has a temperature service life of 20,000 hours of wire. At lower temperatures, the service life of the wire is longer (about 2 times for every 10°C decreases). Common temperature levels are 105°C, 130°C, 155°C, 180°C, and 220°C.

    In fact, the maximum current density can vary from 2.5 A/mm 2 for wires isolated from free air to 6 A/mm 2 for wires in free air. If the wire carries a high-frequency current (above 10 kHz), the skin effect may affect the current distribution on the cross-section by concentrating the current on the surface of the conductor.

    If you provide active cooling by blowing in the air or circulating water, you can get a higher current density-proportional to the cooling effect.

    The cross-sectional area of CCA wire must be 1.6 times that of copper wire to obtain comparable DC resistance. Therefore, copper magnet wire helps to improve energy efficiency in equipment such as electric motors.