The identification of the quality of wires can be carried out from the following aspects:
Appearance inspection: Good THHN/THWN/2 wires and cables should have a neat, smooth appearance, no obvious defects, and uniform color. High quality wires have the characteristics of tight packaging and clear handwriting. The surface of the wire has wire THHN models, such as 6 THHN wire, 12 THHN wire, 10 THHN wire, and 14 THHN wire
Insulation layer inspection: The PVC insulation material should be uniform, free of bubbles, cracks, impurities, and other defects.
Conductor inspection: THHN wire conductors are divided into copper THHN wire and aluminum THHN. Qualified THHN wire conductors should have a glossy and soft feel. Fake and inferior copper core wires have copper cores that are purple black, yellowish or whitish, with many impurities, poor mechanical strength, and poor toughness
Quality certification inspection: The product has the UL MARK mark and a UL certified file number
Flame retardancy test: Use a lighter to ignite the wires and observe if the flame will automatically extinguish. If it does, it indicates that the cable THHN has good flame retardancy
Through the comprehensive application of the above methods, the quality of wires and cables can be effectively identified to ensure safe use.
