Electric wires and cables are used to transmit electricity, which is an indispensable source of energy for mankind and at the same time a dangerous and lurking energy source, so it must be loaded as well as used appropriately. the safest way possible to limit the risk.
Electrical wires and cables are required to be manufactured according to the relevant regulatory standards depending on each country or according to the general IEC standard, the ultimate purpose is to ensure the safety of operation and use, not only for the whole electrical system but also for people and nature.
Of course, when developing and finalizing a standard for electrical cables, there will be manufacturers who comply with that standard and also other manufacturers that do not, leading to poor quality, unqualified power cables. standard on the market.
Somehow, these wires are still used by consumers to this day, but when using these unqualified wires, danger is always lurking. will tell you why.
What is unqualified power cable?
Electric cables are composed of many layers with different functions, but the most basic structure is conductor, insulation and sheath (if any).
- The conductor is responsible for carrying electricity. The general standard stipulates that a conductor must be capable of carrying electricity according to its rated capacity, if the conductor loads less than required, that conductor is unqualified;
- The insulating layer is responsible for keeping the electrical stress only on the conductor instead of moving around or to another conductor, causing danger. In short, the insulating layer has the task of insulating. The specified general standard will mainly relate to the thickness and material of the insulation, whereby if the thickness or material is not specified, it is also considered to be non-standard.
What happens when using unqualified wire?
Based on the above quick analysis, we can identify the problem as follows:
- If the power cable has unqualified conductors: The ability to load electricity below the rated capacity (overload) will cause the wire to heat up, and reaching a certain temperature will melt the insulation, causing a short circuit and a fire.
- If the electrical cable has unqualified insulation: Assuming the insulation is thinner than specified, the insulation pressure will increase and the cable will age faster. An even worse consequence is that the insulation is so thin that high voltages can break through the dielectric strength, making the insulation a conductor and repeating the first situation.
In addition, unqualified power cables may be:
- Unqualified conductor resistance: When the conductor resistance exceeds the standard, it will increase the loss of current flowing through the line, heating the conductor…
- Unqualified tensile strength and elongation at break will greatly reduce the service life of wire and cable …
Excessively thick insulation or sheath is also not a good idea as the thickness prevents the conductor from radiating heat to the surrounding space, there is a high risk of also heating the conductor and eventually shorting.
