How to distinguish inferior wire and cable

Characteristics of inferior wire

1. The cable length is not enough

The main means used by unscrupulous manufacturers is to make a fuss about the length of the wire and cable. The actual length of the wire and cable is less than the nominal length, and the price is calculated according to the nominal length. The most typical is the cloth wrapped into a roll. In the standard, each roll is 100 meters, and the measurement error does not exceed 0.5%, that is, the length of each wire is 100 ± 0.5 meters, and many manufacturers are openly on the certificate. It is marked as 100±20 meters, and the actual length is only about 80 meters. If its price is equivalent to each meter, it is not cheap. Such scams are easier to identify, one is to look at the qualified card; the other is to check the length, because the cloth is soft and easy to measure.

2. The resistance value does not meet the standard

A wire with a resistance value exceeding the standard may be overheated under the same current, thereby accelerating the aging of the outer insulating layer, causing a short circuit and causing a fire; and because the resistance exceeds the standard, the power consumption during the transmission process is greatly increased, and the cost of electricity is increased.

3. Poor raw materials

The first is the concept of copper conductors. Copper conductors account for 80% of the cost of the wire. One of the bad manufacturers is to lower the quality of the copper. Using impurities such as copper at a much lower price, recycling copper, or even smelting copper, the copper content is extremely unstable, resulting in a substantial increase in the resistivity of copper conductors. The second is to reduce the use of copper. The direct consequence of reducing the actual cross-sectional area of the copper core is that the wire is overheated during use, damaging the insulating plastic, causing a short circuit and causing a fire.

The second is to use the plastic broken core used in the insulating layer, which is the same as the copper material. The price difference between a ton of recycled insulating materials and qualified PVC plastic powder is nearly 2,000 yuan, but the recycled insulating materials have high impurity content and low mechanical strength. The aging resistance and electrical insulation performance decline, which directly leads to the leakage of electric wires.

False line identification

1. Look at the label. The content of the wire certificate issued by the regular manufacturer should include: certification mark, certification number, model specification, implementation standard, rated voltage, wire length, production date, manufacturer, inspector, factory name, factory address, fixed telephone, anti-counterfeiting mark, etc. The labels of counterfeit products are often unclear or incompletely printed.

2. Look at the surface. The plastic sheath of ordinary wires is soft and smooth, and the color is uniform. The surface should also be printed with several items on the product certificate, such as: certification mark, certification number, model, rated voltage, implementation standard, factory name, etc., and the handwriting must be clear and not easy to erase.

3. Try bending. It is recommended to bend the wire ends repeatedly by hand. Any product that is soft to the touch, has good fatigue resistance, has a strong plastic or rubber hand, and has no cracks in the wire insulation is a superior product. The fake wire insulation looks thick. In fact, it's mostly made from recycled plastic. As long as you squeeze a little, the squeezed will turn white, and the wire will break 4 to 6 times.

4. Tear insulation. High-quality insulating materials have certain mechanical strength and flexibility, and are not easy to peel off. Poor quality wires can be torn or smashed by hand.

5. Watch the burn. The insulating layer of the wire has a certain flame retardancy. Strip off a section of insulation, ignite with a lighter, and continue to spontaneously ignite after the open flame has deteriorated.

Macro cable

6. Check the thickness. Take a section of insulating layer to see if there are visible pores in the insulating layer and whether the core wire is in the middle of the insulating layer. The non-centering is due to the eccentricity caused by the low process, and the presence of pores indicates that the insulating material used is unqualified. Eccentricity is most likely to leak electricity on the thin edge, and pores will also affect the compressive strength.

7. Look at the copper wire. The color of high-quality copper wire is bright red, and the inferior copper core is purple, black, yellow or white, with high hardness, many impurities, poor mechanical strength, poor toughness, and will break after a little pressure. And there are frequent breaks in the wires. For stranded cords, touch the top of the copper wire with the palm of your hand. It feels flat, has no tingling and is soft to the touch. Otherwise, it is inferior wire.