When purchasing wires and cables, avoid pitfalls with these identification tips. Be sure to save them!

1. The quality of wires and cables varies greatly, and distinguishing good from bad is crucial.

In modern society, wires and cables are like the "blood vessels" and "nerves" that permeate our bodies, widely used in various fields such as homes, industry, and communication, supporting power transmission, information transfer, and the operation of various devices. However, the quality of wires and cables in the market is uneven, with inferior products acting like "time bombs," constantly threatening people's lives and property safety. Fires, short circuits, and other accidents caused by the use of inferior wires and cables are not uncommon, leading to significant economic losses and, in severe cases, even endangering lives. Therefore, mastering the methods to distinguish the quality of wires and cables is essential for ensuring electrical safety.

2. Check the appearance: details reveal the truth.

• Checking the appearance of wires and cables is the first step in identifying their quality and is a relatively intuitive method. The appearance of legitimate products is usually smooth and even, indicating that manufacturers have strict control over the selection of raw materials and processing technology during production. High-quality copper core wires have a purple-red, shiny core that feels soft to the touch, has high mechanical strength, and is flexible, making it difficult to break; while inferior copper core wires often have a purple-black, yellowish, or whitish core with obvious impurities, poor mechanical strength, and low flexibility, making them prone to breakage with slight force, and often have internal wire breaks.
• Next, look at the insulation outer layer. The outer layer of legitimate wires and cables is dense, soft, and smooth, with pure and even color, free of bubbles, lumps, or damage. When bent repeatedly by hand, it feels soft, has good elasticity, and high fatigue resistance, with no cracks on the insulator. In contrast, inferior products often have dull colors and loose textures, possibly made from recycled plastic, and can easily show white marks when squeezed by hand, with a risk of wire breakage after a few bends.
• Product labeling is also key. The markings on legitimate wires and cables are clear and not easily erased, printed with trademarks, specifications, voltage, manufacturer name, address, and other detailed information, and carry relevant marks such as 3C certification. The markings on counterfeit products are often blurred, incomplete, or incorrect, and may even lack any certification marks.

3. Inspect the labels: recognize them."3C" certification.

• The "3C" certification mark is a basic guarantee of the quality of wires and cables; it is like the product's "identity card," indicating that the product meets the requirements of the national mandatory product certification system. Consumers must recognize this mark when purchasing. The certification mark of legitimate products is clear and complete, and can be verified for authenticity and validity by entering the certification number on the China Quality Certification Center's official website (http://www.cqc.com.cn). In addition to the "3C" mark, product labeling should also include model specifications, implementation standards, rated voltage, manufacturer name, and address, and this information must be consistent with the certification. If the labeling is blurred, incomplete, or inconsistent with the certificate, it is likely a counterfeit product.

4. Measure dimensions: precise measurement ensures safety.

(1) Measure the core diameter.

The core of the wire is the "heart" of the wire and cable, and its diameter directly affects the current carrying capacity. National standards specify the core diameter for different specifications of wires and cables, with tolerances usually controlled within a very small range. Taking the common 2.5 square millimeter copper core wire as an example, its standard core diameter is about 1.78 millimeters. When measuring, a caliper with an accuracy of 0.01 millimeters can be used; place the caliper on the core, keeping it as vertical as possible, and measure several positions to take an average value to reduce measurement error. The core diameter of high-quality wires and cables precisely meets the standards, ensuring stable carrying of rated current and avoiding hazards such as overheating and short circuits caused by overly thin cores; while inferior products often have cores that are too thin to meet electrical needs, easily leading to electrical accidents with prolonged use.

(2) Check the insulation layer thickness.

The insulation layer is the "protective shield" that ensures electrical safety, and its thickness must meet national standards. If the insulation layer is too thin, it may break down under normal voltage, leading to leakage and short circuits, endangering personal and equipment safety; while if it is too thick, although insulation performance improves, it increases costs and reduces the flexibility of the wire, making installation and wiring difficult. The thickness of the insulation layer varies for wires and cables of different voltage levels and specifications. To measure the insulation layer thickness, a micrometer or professional thickness gauge can be used, measuring several points to take an average value to ensure accuracy. Additionally, pay attention to whether the insulation layer has issues such as eccentricity or air holes, as these defects can severely weaken insulation performance.

5. Test performance: practice reveals the truth.

(1) Bending test.

The bending test can intuitively reflect the flexibility and fatigue resistance of wires and cables. Take a wire end and bend it repeatedly by hand; high-quality wires feel soft, have good fatigue resistance, and the plastic or rubber outer layer feels elastic, with no cracks on the insulator; while inferior wires often have insulation layers made from recycled plastic, which will turn white when pressed, and may show wire breakage after a few bends.

(2) Burning test.

According to regulations, the insulation layer of wires and cables should have certain flame retardant properties. Strip a small section of the insulation layer and ignite it with a lighter; high-quality products will extinguish quickly after leaving the flame, and there will be no continued burning, with little smoke and no dripping; while inferior products will continue to burn after leaving the flame, producing thick, pungent smoke, and may even have dripping materials, which can easily cause fires. For example, some inferior PVC insulated wires will spread flames rapidly when ignited, making them difficult to control, while compliant wires will only burn briefly before extinguishing on their own.

6. Choose legitimate channels for purchase: ensure quality.

When purchasing wires and cables, it is crucial to choose legitimate channels. Legitimate merchants and large building material markets usually cooperate with legitimate manufacturers, ensuring product quality and providing comprehensive after-sales service to promptly address consumer issues. Well-known brand official flagship stores, whether online or offline, have strict quality control systems, with products traceable from production to sale, allowing consumers to purchase with confidence. In contrast, when shopping online, if one only seeks cheap prices and chooses small stores with prices far below market value and no brand reputation, they are likely to buy counterfeit products. Wires and cables sold by street vendors have no quality guarantee, and once problems arise, it is impossible to hold anyone accountable. Therefore, for electrical safety, do not lose big for small gains; choose reliable purchasing channels.