1、 Greedy for low prices.
This is a common misunderstanding of many users and even some enterprises in the exercise of wires and cables. In order to save money and ignore safety, some users choose low-quality wires and cables with low price, no guarantee of quality and great potential accidents. We know that due to the safety of wires and cables and other factors, the price of wires and cables can not meet the requirements of some users. However, some individual and private enterprises are unable to manufacture wires and cables that meet the requirements of national standards in terms of material selection, production technology and testing means, and their safety will not be guaranteed. In addition, they make articles on short feet and less meters, flooding the market with their low prices to cater to some users. Therefore, please do not covet cheap wires and cables.
2、 Improper model selection.
Some users often choose the wrong model because they do not know enough about their own electrical appliance use requirements and environmental conditions, and do not know enough about the use scope, requirements and performance of wire and cable models. For example, the slag truck in front of the furnace of a steel plant is powered by a motor, and the temperature in front of the furnace is as high as 800 ℃ ~ 900 ℃. Under such environmental conditions, because the plant knows nothing about the special requirements for wires and cables, it selects the general rubber sheathed flexible cable to fill YC type. As a result, the service time is short and the sheath is scorched, which not only affects the production, but also wastes the economy. After consultation, the fire-resistant and flame-retardant cable is selected, which reduces the pain and economic loss of cable replacement and ensures the normal production of the enterprise.
Flame retardant or fire-resistant cables with fire-fighting function shall be used in some important departments, high-rise buildings, computing centers, chemical industry, public entertainment places, personnel concentration and other places; The Ministry of coal stipulates that cables used in deep coal mines must be flame retardant;
There are also special performance requirements for elevator cables, welding machine cables, motor lead wires, etc. In the actual use of these special wires and cables with special requirements, some enterprises, especially individual enterprises, often lack understanding of them and refuse to use them;
Some enterprises ignore the requirements of the Ministry of coal that the cables used in deep coal mines must be flame retardant, but buy General rubber sheathed flexible cables; There are also karaoke halls and crowded places where some general wires and cables without fire-fighting function are installed, resulting in potential accidents.
It is recommended that you pay attention to the following points when purchasing wires and cables:
CCC certification mark
Wires must have CCC certification mark. Wire and cable products are products with national compulsory safety certification. All production enterprises must obtain “CCC” certification certified by China Electrotechnical Product Certification Commission, obtain “CCC” certification mark, and have “CCC” certification mark on the certificate of conformity or products. Wire is related to power safety. The quality of wire will affect our life and property safety, so we must choose wire products with CCC certification mark.
The appearance of a good wire product should be smooth, round and uniform in color. Therefore, when purchasing, you should disassemble the wire and check it to see if the appearance is uniform in color. If there is discoloration, it proves that the quality of the wire is not qualified.
The wire product certificate will clearly print the “CCC” certification mark, trademark, model and specification, rated voltage, length, inspection, manufacturing date, executive standard, factory name, address, telephone and other marks, and conform to the products. These will be the production products of regular manufacturers. We should see them clearly when purchasing.
The conductor of the wire shall be glossy, and the DC resistance and conductor structure size shall meet the requirements of national standards. The products of wires and cables that meet the requirements of national standards, whether aluminum conductors or copper conductors, are relatively bright and oil-free. Therefore, the DC resistance of conductors fully meets the national standards, with good conductivity and high safety. Wire selection method
Wire specification is very important. Bvv2 should be adopted for general household power cord × 2.5 and bvv2 × 1.5 type of wire. BVV is the national standard code for copper sheathed wire bvv2 × 2.5 and bvv2 × 1.5, representing 2-core 2.5 mm2 and 2-core 1.5 mm2 respectively. In general, bvv2 × 2.5 main line and trunk line, bvv2 × 1.5 make single electrical branch line and switch line. Bvv2 for unidirectional air conditioning special line × 4. Special ground wire shall be provided.