The products of wire and cable manufacturers do not distinguish cables by their advantages and disadvantages in terms of width, thickness, etc.

1. The hazards of fake and inferior wires

Fish-eye-mixed products are not uncommon in the market. Even the wire industry has some inferior products mixed in, which seriously affects our electricity safety and lays long-term hidden dangers in our lives. If fake and inferior wires and cables are used, they may cause short circuits and electric shocks, and may cause fires, causing casualties. In recent years, more than 40% of fires have been caused by electrical faults, and black core wires and cables with copper cores "shrinking" are one of the main reasons.

Second, the characteristics of shoddy wires

1. The cable length is not enough

The main method used by illegal manufacturers is to write about the length of the wire and cable. The actual length of the wire and cable is less than the nominal length, and the pricing and charging shall be carried out according to the nominal length. The most typical is the cloth wire packaged in rolls. The national standard stipulates that each roll is 100 meters, and the measurement error is not more than 0.5%, that is, the length of each roll is 100 ± 0.5 meters, and many manufacturers are blatantly in the qualified card. It is marked 100±20 meters, and its actual length is only about 80 meters. If the price is equivalent to per meter, it is not cheap. This kind of fraud is easier to identify, one is to look at the qualified card; the other is to check the length of the sample, because the wire is relatively soft and easy to measure.

2, the resistance value does not meet the national standard

The temperature of a wire with an excessive resistance value may be too high under the same current, which will accelerate the aging of the outer insulation layer and cause a short circuit to cause a fire. In addition, due to the excessive resistance, it will greatly increase the energy consumption of the power transmission process and increase the cost of electricity.

3, the raw material is poor

The first trick is to use copper conductors. Copper conductors account for 80% of the cost of wires. The first one is to reduce the quality of copper. Adopting much lower-priced impurity copper, recycling copper, and even smelting copper by the local method, the copper content is extremely unstable, resulting in a large increase in the resistivity of the copper conductor. The second is to reduce the amount of copper. To reduce the actual cross-sectional area of ​​the copper core, the direct consequence of these two methods is that the wire overheats during use, damages the plastic of the insulation layer, and causes a short circuit to cause a fire.

The second trick is to make a bad eye on the plastic used in the insulating layer, which is degraded like copper. The price of recycled insulating material per ton and qualified PVC plastic powder is nearly 2,000 yuan, but the recycled insulating material has high impurity content and low mechanical strength. , Anti-aging performance and electrical insulation performance decline, this approach will directly lead to electrical leakage in the wire.

3. Identification of fake and inferior wires

1. Look at the label. The content of the wire certificate produced by a regular manufacturer should include: 3C certification mark, certification number, model specification, implementation standard, rated voltage, wire length, production date, producer, inspector, factory name, factory address, fixed telephone, anti-counterfeiting label Wait. The labels of counterfeit products are often unclear or incomplete.

2, look at the surface. The plastic sheath of the regular wire is soft and smooth, and the color is uniform. On its surface, there should also be several items printed on the product certificate, such as: 3C certification mark, certification number, model, rated voltage, executive standard, factory name, etc. At the same time, the handwriting must be clear and not easy to erase.

3. Try bending. It is recommended to bend a wire head repeatedly by hand. Anything with soft hand feel, good fatigue strength, plastic or rubber hand feeling and elasticity, and no cracks on the wire insulator are excellent products. The insulation layer of the fake wire looks very thick, but in fact most of it is made of recycled plastic. As long as you squeeze a little harder, the squeezed part will become white, and the wire will be broken after 4-6 times of bending;

4. Tear insulation. High-quality insulating materials have a certain degree of mechanical strength and flexibility, and cannot be torn easily. Inferior wires can be torn off or pinched off by hand;

5. Look at the burning. According to regulations, the insulation layer of the wire has a certain flame retardancy. Peel off a section of the insulating layer and ignite it with a lighter. It is inferior wire that can continue to spontaneously ignite after leaving the open flame.

6. Check the thickness. Cut a section of the insulating layer to see if there are visible pores in the section of the insulating layer, and whether the core is located in the middle of the insulating layer. What is not in the center is the eccentricity caused by the low craftsmanship, and the presence of pores indicates that the insulating material used is unqualified. Severe eccentricity is most likely to leak on the thinner side, and the presence of pores also affects the compressive strength.

7. Look at the copper wire. The color of high-quality copper wire is bright and reddish, while the inferior copper core wire is purple-black, black, yellow or white, with high hardness, many impurities, poor mechanical strength, poor toughness, and it will break if you apply force. , And there are often disconnections in the wires. For multi-strand flexible wires, lightly touch the top of the copper wire with your palm, it should feel smooth, without tingling sensation, and feel soft. Otherwise, it is a low-quality wire.

8. Look at the price. Due to the low production cost of counterfeit and shoddy wires, vendors often sell them at low prices under the guise of low prices and good quality when selling.

According to the above simple verification methods, it can basically identify whether it is a good or bad wire. If you need to use data to speak, please use the corresponding instrument to detect the length, diameter, thickness, resistance, voltage resistance and strength of the wire.

One, formula

Look carefully at the label printing, the handwriting is blurred and the address is unknown.

Twist the insulating skin with your hands, and the color fades and the characters are lost, and the quality is poor.

Then use your fingernails to mark and pinch the line, and the line will be cut off.

The insulated wire is bent repeatedly, and it breaks three to four times.

Ignite the wire insulation with fire, and spontaneously ignite when leaving the open flame wire.

The wire core is usually aluminum and copper, and the color becomes darker and lighter.

Measure the inner diameter and outer diameter carefully, and look at the Pisone when weighing.