When selecting cables, you should select cables according to your own site use, and do not be greedy for cheap.
I think the cable is cheap and can guarantee that it is national standard. In nine out of ten, it is used to play side ball. Fooling users who are not professional and do not understand the industry. In order to enable the majority of users to better understand the quality standards of cable and wire and self-determination of national standards and non-standard differences. Let's make a simple understanding by combining the actual situation that engineering users and cable industry often encounter.
Generally, there are three types of cables in the use of engineering users and construction projects:
1. National standard cable: the cable produced according to the technology of relevant cable standards issued by the state is called international line for short.
2. Line standard cable: according to the industry standard, there are less Jerry built cables, but they do not affect the performance.
3. Non standard cable: the product that is born to meet the market demand. Nowadays, the application of wire and cable is more and more extensive, with it, there are more and more kinds of wire and cable on the market.
So, how to distinguish "national standard" and "non-standard" of wires and cables?
It is suggested that you have a look, two tests, three weighing, four price comparison, five copper quality inspection, six quality inspection, and six moves.
First look: it depends on whether the wire and cable products have quality system certification, whether the certificate is standardized, whether there is a factory name, factory address, inspection seal, production date, and whether there is a trademark, specification, voltage, etc. printed on the wire. Also look at the cross-section of the wire copper core. The superior copper is bright in color and soft in color, otherwise it is inferior.
Second try: a wire head can be bent repeatedly by hand. Those with soft hand, good fatigue resistance, large flexibility of plastic or rubber hand and no crack on the wire insulator are excellent products.
Three scales of weight: for wires and cables of good quality, the weight of each 100m is generally within the specified weight range. For example, the common plastic insulated single stranded copper core wire with a cross-sectional area of 1.5mm2 weighs 1.8-1.9kg per 100m; the plastic insulated single stranded copper core wire with a cross-sectional area of 2.5mm2 weighs 3-3.1kg per 100m; the plastic insulated single stranded copper core wire with a cross-sectional area of 4.0mm2 weighs 4.4-4.6kg per 100m, etc. The wires with poor quality are insufficient in weight, length or copper core impurities. If it is a cable, especially a large-scale cable, the soil method of weighing is to reflect whether the copper content of the cable is up to the standard and whether the conductor section is up to the standard.
The simple method is to steal copper to make small section cable. If the copper content of the cable can not reach the weight range of the allowable error stipulated by the state after weighing, it can be regarded as non-standard basically.
Four price comparison: due to the low production cost of fake and shoddy wires, vendors often sell at a low price under the guise of low price and good quality, which makes people fall in the trap. Therefore, when buying, be careful not to be fooled by the "good quality and low price" advertised by the merchants. 5. Copper. Qualified copper core wires shall be purple red, glossy and soft.
5. Copper material: the copper core of the fake copper core wire is purple black, yellow or white, with many impurities, poor mechanical strength and toughness. If you use a little force, it will break, and the wire often breaks. During the inspection, you only need to strip one end of the wire, and then use a piece of white paper to slightly rub the copper core. If there is black material on the white paper, it means that there are many impurities in the copper core, it can be identified as "non-standard" wire and cable.
6. Quality inspection: in case of divergence of cable quality, it can be sent to a third-party inspection agency for inspection. Based on whether the authoritative test report is qualified.