Why do wires and cables short-circuit and how to avoid it?

Do you know why the wires and cables short-circuit? Next let chaoyang cable small make up to tell you how it works. It is a well known fact that electrical resistance produces heat when wires and cables work. Wire and cable wire power is very small, heating power also has a professional formula can be calculated: q = I ^ 2 r. Q = the I ^ 2 R said electric current through a conductor, the greater the the greater the heating power of it (R is basically constant); If the current is constant, the heating power of the wire is constant. The heat released during operation will be absorbed by the wire itself, causing the wire temperature to rise. Although the wire in operation, although constantly absorb the heat released by the current work, but the temperature will not rise indefinitely. Because while the wire is absorbing heat, it's also releasing heat to the outside world, and actually the wire is getting hotter, and eventually the temperature stays constant at some point. At this constant point, the conductor absorbs heat, radiates heat at the same power, and the conductor is in thermal equilibrium. The ability of wires to withstand higher temperatures is limited, and it is dangerous to continue working beyond a certain temperature. The maximum temperature corresponds naturally to the maximum current. The overload of the wire directly causes the temperature in and around the wire to rise. Rising temperatures are the most immediate cause of such fires.

Overload can lead to damage to the insulation between the inner cores of multiple wires and cables, resulting in short circuits, burning equipment, and fire. Multi-core wire and cable wires are separated by insulation layer. Overload insulation layer softens and damages, resulting in direct contact between two or more conductors of wire and cable, resulting in short circuit and combustion equipment. At the same time short circuit instant high current produced high temperature line fire, wire melting, melting wire fell on the surrounding combustible and cause a fire. It is possible for an overloaded conductor to transfer heat to a nearby flammable temperature, and a lower flammable material near the ignition point to ignite and cause a fire. This danger is particularly pronounced in warehouses where flammable materials are stored and in buildings where flammable fittings are made.

Overloading can also cause joints in the line to overheat, which speeds up the oxidation process. The oxidation of the connection point is easy to produce an oxidation film which is not easy to conduct electricity. The oxidation film increases the resistance between the contact points, leading to ignition and other phenomena and causing fire.

So how do you prevent wires and cables from overloading and catching fire? Take a look at the shaanxi xi 'an wire and cable manufacturers small make up how to say!

In the course of the circuit design, the appropriate type of wire and cable shall be selected to accurately allow the site capacity and to take into account the possibility of new capacity. Large capacity, should choose thicker wire and cable. Line design and reasonable selection are the key steps to prevent overload. If the design choice is improper, it will be difficult to correct the inherent hazards. Some small projects, places without serious design choices. Free choice, laying lines, that's very dangerous. New electrical equipment, electrical equipment should take full account of the original capacity. The original wire and cable do not meet the requirements, should be redesigned, transformation.

The line should meet the relevant requirements, so that the electrician and construction personnel lay. Line laying conditions directly affect the heat dissipation of wires and cables. Generally speaking, it is not suitable for laying electric wires and cables to pile up through inflammable and flammable materials, which will lead to poor heat dissipation of wires, heat accumulation, and the possibility of ignition of flammable articles around, and increase the fire danger caused by overload. The decorative ceiling line in the public entertainment area should be protected by steel pipe, so that the ceiling and the line are separated, so that the flame will not fall in the case of overload, short circuit and so on, and the fire can be avoided.

Strengthen power management, avoid random wiring, confusion, careful use of mobile socket. Chaotic wiring, chaotic wiring, the use of a portable power socket is actually the addition of electrical equipment to a section of the line, increasing the electrical flow that can lead to overload. Walls with more removable jacks than fixed sockets, and if the removable socket USES too much electrical equipment, the original wiring must be unbearable. For higher power equipment, electrical appliances should be set up a separate line, should not use the mobile power socket as the wiring source.

Accelerate the renovation of old lines to eliminate fire hazards. Old enterprises, old residential areas and other units, due to the use of long time, many lines aging, over the service life. Some lines with current carrying capacity, even if small, can hardly bear such load, and there is a risk of overload display. Especially in the old residential areas, the lines have been aging for a long time, but with the improvement of people's living standard and the increase of household appliances, the electricity consumption is still increasing year by year, which is really worse. For the old line, should be timely urged, coordination, as soon as possible to promote rectification, eliminate fire hazards, to ensure safety.