When the single-phase voltage is 220 volts, the cable made of copper wire needs 240 square meters, while the cable made of aluminum wire needs 300 square meters. When the load is 380 volts three-phase voltage, the cable made of copper wire needs 70 square meters, while the cable made of aluminum wire needs 95 square meters.
Method of selecting high quality cable
1. It is better to choose cables of international standards, so that the protection can be higher. Therefore, before buying the cable, it depends on whether it belongs to the international standard brand, and depends on the certificate, trademark and specification of the product. If the cable doesn't even have a basic trademark, you should be very cautious.
By observing the cable, we can find its quality. At this time, it is necessary to peel off the cable in this section to expose the inner conductor: if the inner copper wire is purple, the quality will be better; If the brass wire is ok, the quality is ok, but the black copper wire is very poor, so be careful when buying it.
3. Touch the conductor of the wire with your hand. If the surface of the wire is smooth and there is no burr, then the quality of the wire is high. However, the surface of the conductor feels rough and tingling, indicating that there is something wrong with the quality. Scrape the insulating skin with your nails again to see if there are any traces.