When selecting wires and cables, the following steps can be followed:
Check the "CCC" certification mark: Electric wires and cables are products subject to mandatory national safety certification. All production enterprises must obtain the "CCC" certification from the China Electrical Products Certification Commission, obtain the "CCC" certification mark, and have the "CCC" certification mark on the certificate of conformity or product.
Check the surface markings of cables: According to national standards, there should be continuous markings on the surface of wires, including the manufacturer's name, product model, and rated voltage. Consumers should pay attention to whether the manufacturer name, product model, rated voltage indicated on the certificate of conformity are consistent with the printed logo on the surface of the wire when purchasing wires and cables, in order to prevent counterfeit products.
Check the appearance of the cable: The product has a smooth and round appearance with uniform color. The appearance of the produced wire and cable products meets the standard requirements, smooth and round, with uniform color. Counterfeit and inferior products have a rough and dull appearance. For rubber insulated flexible cables, it is required to have a round appearance, and the sheath, insulation, and conductor should be tightly sealed and not easily peeled off. Counterfeit and inferior products have a rough appearance, large ovality, and low insulation strength of the sheath, which can be easily torn open by hand.
Check conductors: Wire and cable products that meet national standards, whether they are aluminum or copper conductors, are relatively bright and free of oil stains. When selecting wires, attention should be paid to whether the conductor diameter matches the cross-sectional area indicated on the certificate of conformity. If the conductor cross-sectional area is too small, it is easy to cause the wire to heat up and cause danger.
Measuring length: Length is the main intuitive method to distinguish between products that meet national standards and counterfeit and inferior products. When choosing, do not be tempted by cheap prices. Choose wires and cables with a length of 90m or 80m, or even without a length label. The length must meet the standard requirement of 100 ± 0.5m, which is based on 100 meters and allows for an error of 0.5 meters.
Check weight: If the length is sufficient, then weigh it. How to calculate the weight of cables? You can look up my previous articles. This is a method of measuring whether the cross-section of a cable or wire meets the standard.
Check the label: National standards will label the cable with the model, factory name, national standard, and other words. If it's not a standard line, they dare not take it. This must be seen.
Check the price: As the saying goes, you get what you pay for. Cheap prices definitely have their own reasons, so if you encounter prices that are outrageous, you should be very cautious. Because the price is lower than the cost price, it must be non-standard.
When selecting wires and cables, in addition to the methods mentioned above, the following factors can also be considered:
Selection of wire and cable models: Choose the appropriate wire and cable model based on its purpose, laying conditions, and safety. For example, power cables, overhead insulated cables, control cables, etc. all have their own application scenarios. In addition, according to different laying conditions, general plastic insulated cables, steel tape armored cables, steel wire armored cables, anti-corrosion cables, etc. can be selected. If safety needs to be emphasized, flame-retardant cables, halogen-free flame-retardant cables, fire-resistant cables, etc. can be selected.
Selection of wire and cable specifications: When determining the usage specifications (conductor cross-section) of wire and cable, factors such as heat generation, voltage loss, economic current density, and mechanical strength should be considered. For example, due to the high load current of low-voltage power lines, the cross-section is generally selected based on the heating conditions, and then the voltage loss and mechanical strength are verified; Low voltage lighting lines, due to their high requirements for voltage levels, can first select the cross-section according to the allowable voltage loss conditions, and then verify the heating conditions and mechanical strength; For high-voltage lines, first select the cross-section according to the economic current density, and then verify its heating conditions and allowable voltage loss.
In summary, selecting wires and cables requires comprehensive consideration of multiple factors. By viewing the "CCC" certification mark, inspecting conductors and appearance, measuring length and weight, and other methods, consumers can help identify the quality of wires and cables. Meanwhile, choosing the appropriate model and specifications is also very important. If you are not familiar with the specifications and models of wires and cables, you can consult professional or manufacturer sales personnel for advice.