Certificate specification
See if there is a complete certificate in the package. The certificate of conformity shall include complete information such as specifications, implementation scale, rated voltage, length, date, factory name and address. See if there is "CCC" and the production license number of China national compulsory product certification; See if there is a quality system certificate; See if the certificate is standardized; See if there are any trademarks, specifications, voltages, etc. Printed on the wire.
dimension error
In the relevant standards, the error of wire length is less than 2% and the diameter of cross section is less than 0.02%, but there are a lot of phenomena of short length and fake cross section in the market.
Copper core color
The color of copper is also a criterion for judging the quality of wires. The copper core of qualified copper core wire should be purplish red, shiny and soft to the touch. The fake copper core is dark purple, black, yellow or white.
Insulating rubber
Look at the insulating rubber outside the wires. The insulating layer of fake wires seems to be very thick. In fact, most of them are made of recycled plastics. As long as you squeeze it a little hard, the squeezed place will turn white and lose powder.
Tension range
In addition, wires with good quality are generally within the specified weight range. For example, the common plastic insulated single-stranded copper core wire has a cross-sectional area of 1.5mm2 and a weight of 100m1.8 ~1.9kg.. It is written on the product label.