When choosing the cable, choose the cable according to the use of the site, don’t covet cheap. Think that the cable price is cheap and can ensure that it is the national standard, nine out of ten are playing edge ball. Cheat the users who are not professional and don’t understand the industry. The quality of non-standard cable and national standard can be more clearly recognized by users. Now we combine engineering users and cable industry often encounter the actual situation, let us do a simple understanding.
Cables and wires are generally used in engineering users and construction projects, and there are three types of cables
- National standard cable: according to the relevant cable standard technology issued by the state, the cable is referred to as the international line.
- Line standard cable: according to the industry standard, there are less shoddy work and materials, but it does not affect the performance.
- Non standard cable: to meet the needs of the city should be pregnant products. Nowadays, the application of wire and cable is more and more widely, and the types of wire and cable sold in the market are more and more.
So, how to distinguish the “national standard” and “non-standard” of wires and cables?
Look: it depends on whether the wire and cable products have quality system certification certificate, whether the certificate is standardized, whether there is factory name, address, inspection seal, production date, and whether the wire is printed with trademark, specification, voltage, etc. But also look at the cross-section of the wire copper core, superior grade copper color is bright, color is soft, otherwise it is inferior.
Try: take a wire head and bend it repeatedly by hand. If the handle is soft, the fatigue strength is good, the plastic or rubber handle is elastic and there is no crack on the wire insulator, it is a top-grade product.
Weighing: the weight of wires and cables with good quality is generally within the specified weight range every 100m. For example, the commonly used plastic insulated single strand copper core wire with cross-sectional area of 1.5mm2 weighs 1.8-1.9kg per 100m; for 2.5mm2, it weighs 3-3.1kg per 100m; for 4.0mm2, it weighs 4.4-4.6kg per 100m. Poor quality wire weight is not enough, or the length is not enough, or the wire copper core impurities are too much. For cables, especially for large-scale cables, the soil method of weighing is the simplest way to reflect whether the copper content of the cable reaches the standard and whether the conductor cross-section is up to the standard. Generally, there are cables with small cross-section made of stolen copper. If the copper content of the cable can not reach the weight range of allowable error specified by the state after weighing, it can be basically regarded as non-standard.
Price comparison: due to the low production cost of fake and shoddy wires, vendors often sell them at low prices under the guise of low price and high quality. Therefore, when buying, you should be careful not to be confused by the “high quality and low price” advertised by the merchants, and finally be cheated. 5. Copper. Qualified copper core wire copper core should be purplish red, glossy, soft handle.
Copper material: the copper core is purple black, yellowish or white, with many impurities, poor mechanical strength and poor toughness. It will be broken with a little force, and the wire is often broken. When checking, you only need to strip a section of the wire, and then rub it on the copper core with a piece of white paper. If there is black substance on the white paper, it indicates that there are more impurities in the copper core, which can be regarded as “non-standard” wire and cable.
Quality inspection: in case of divergence of cable quality, it can be sent to a third-party testing agency for testing. Based on whether the authoritative test report is qualified or not.