The electric wire of the national standard is the electric wire produced in accordance with the national standard. General household, common wire is in line with the standard specifications and performance, the national standard stipulates the common 5 specifications and performance.
Standard Editor
1. The appearance standard, the electric wire must have the certification mark, the manufacturer, the line diameter and so on, the ground wire uses the yellow green insulating layer
2. Mechanical strength
3. The insulation of the sheath (generally greater than 100M omega) and the pressure resistance (1500V below 500V)
4. The line resistance (certain line diameter, electrical conductivity, length is not greater than a certain resistance)
5, under the high temperature impact 150 degrees, low temperature -30 degree of wire may not appear cracking and so on.
The editors of the national standard and the non national standard
The national standard line is 100 + 0.5 meters / roll
There are only 60-75 meters / rolls of non - marking.
1. Look at it
See whether there is quality system certification, see whether the certificate is standardized, see whether there are factory names, factory locations, inspection chapters, production date, and see whether there are trademarks, specifications, voltage and so on. Also look at the cross section of wire copper core, the superior products of copper bright color, color and lustre, otherwise it is the secondary.
2. Try to try
It is advisable for a wire head to be repeatedly bent by hand, which is soft and anti fatigue strength, plastic or rubber feel elastic and no cracks on wire insulation are excellent products.
3. Weigh the weight
Good quality wires are generally within the specified weight range. For example, the commonly used plastic insulated single strand copper core with a cross-sectional area of 1.5 mm2, the weight of every 100 m is 1.8 to 1.9 kg; the 2.5 mm2 plastic insulated single stranded copper core line, each 100 m weight is 3 ~ 3.1 kg; 4 mm2 plastic insulated single stranded copper conductor, 100 m weight is 4.4 to 4.4 kg. Poor quality wires are not enough, either the length of the wire is not enough, or the copper core of the wire is too much.
4. Look at the copper
The copper core copper core of the qualified copper core should be purple red, luster and soft hand. However, the copper core of fake and inferior copper core is purple black, yellowish or partial white. There are many impurities, poor mechanical strength and poor toughness. It will break if a little force is applied, and the wire break phenomenon often occurs. When checking, you just peel the wire 2 cm, then rub it on the copper core with a piece of white paper. If there is black substance on the white paper, it means that there are more impurities in the copper core. In addition, the insulating layer of the fake and shoddy wires seems to be very thick. In fact, most of them are made of recycled plastic, with a long time, and the insulation layer will be aging and leakage.
5. Look at the price
As the cost of making fake and shoddy wires is low, the sellers often sell at low price under the guise of good price and beauty.