Requirements for Purchasing High-Voltage Cables
1. Check the packaging. Wires that meet national standards are often well-made, neatly laid, and feel high-quality when held.
2. Open the packaging and inspect the wires inside. For wires 1.5-6 square meters in size, the national standard requires a sheath (insulation thickness) of 0.7mm. Anything very thick is non-standard, and the core is likely to be undersized. Pull the sheath hard; if it doesn't tear easily, it's generally national standard.
3. If it goes out within 5 seconds after being burned, it's flame-retardant.
4. Check the core. The brighter the core material (copper), the better. The copper should be uniform, shiny, and free of gradations. National standards require oxygen-free copper for the core. Non-standard materials, such as black-rod copper, may pose a safety hazard.
5. There are certain requirements for the thickness of the core, but they're not very strict. However, the error won't be significant; it's a very small difference, generally invisible to the naked eye.
6. Length: While it's not mandatory to mark lengths in meters, many manufacturers do. Marking lengths in meters doesn't necessarily conform to national standards, and national standards generally don't include meters. Non-standard markings are just a means to an end.
7. Wires must be marked with certain markings. Any length not exceeding 500mm will have a similar marking. These markings typically include the product's trademark, manufacturer's name, and applicable standards.
