Visual Inspection and Identification:
1. PVC Sheath: A high-quality cable will have a smooth surface with a regular "unevenness" in the inner mesh, indicating good manufacturing and no internal slippage. If the sheath feels loose when pinched or lacks this texture, it may be a low-quality cable.
2. Shielding Layer Check: Examine the copper mesh for sufficient coverage and proper tinning. Pure copper wires are soft, while aluminum-magnesium alloy wires are much harder. A sparse, uneven mesh that doesn't adhere well to the insulation layer is a sign of poor quality.
3. Core Wire Diameter: For SYV cables, the diameter should be around 0.78–0.8 mm, while SYWV cables typically have a 1.0 mm core. Recently, some SYV75-5 cables have a 1.0 mm diameter, but their impedance might not be 75 ohms, making them unsuitable for 75-ohm systems.
4. Adhesion Test: Cut the insulation layer at an angle and pull the core wire in the direction of peeling. If the core and insulation separate easily, the cable has poor adhesion and is likely substandard.
5. Longitudinal Tensile Test: Take one meter of the cable, strip off 10 cm sections of the core, insulation, shielding, and outer jacket. Pull two adjacent layers in opposite directions. A good cable will resist pulling, while a lower-quality one will come apart easily—especially important for elevator cables, where many so-called "elevator-specific" cables fail this test.
Fire Test:
It can be challenging for consumers to distinguish between real and fake copper wires. Many counterfeit options are highly realistic, making it hard to tell the difference. Here’s how to identify common types of fake copper wires:
1. General Fake Copper Wires: These include copper-clad aluminum, copper-clad magnesium-aluminum alloy, copper-clad steel, and copper-clad iron. They often have poor conductivity and are used in low-quality cables.
2. High-Imitation Fake Copper Wires: These contain a mix of real copper and copper-clad alloys, sometimes coated with electroplated copper. While they look better, they are still not pure copper and may cost more than standard fake wires.
3. Non-Standard Copper Wires: These are made from materials other than oxygen-free copper, leading to poor signal transmission. Some may also have fewer cores than specified.
If you forget the types of fake copper wires, you can perform a simple fire test. Take a small piece of the copper wire and burn it using a windproof lighter. Real copper is heat-resistant and won’t deform quickly. However, copper-clad aluminum or magnesium-aluminum alloy will bend rapidly, and copper-clad steel or iron will become malleable after burning. This method can help identify the authenticity of the cable material effectively.
Shanghai Janetec Electric Co., Ltd. , https://www.janetecelectric.com