Diagnosis method:
Pay attention to the surface of the insulation and coating, in most non-standard wires and cables, the insulation and coating can be easily torn into pieces by applying a small force even by hand, or a piece of their surface can be scratched and separated with a nail.
Usually, in fake wires and cables, low-quality and cheap raw materials are used. To reduce the price in the material structure, flammable oils such as paraffin and diesel are used as softeners, which causes the flame to spread during a fire.
To identify the type of material, set fire to about 10 cm of the coating or insulation based on PVC material and after it ignites, remove the flame from the vicinity of the sample and wait for it to extinguish itself. If it does not turn off or emits the smell of paraffin candle or diesel when burning, you have a poor quality cable.
Note: The gas emitted from the burning of PVC materials is toxic, perform the above test preferably in a well-ventilated environment and in compliance with safety and health principles.
Conductor in wire and cable
The most common and widely used type of metal in the wire and cable industry is copper due to its high conductivity.
Remember, in relation to copper wires and cables, the copper conductor must meet conditions such as:
– Made of softened (annealed) pure copper.
– Have a completely transparent and shiny surface.
– Not oxidized (copper threads should not be black).
– Be flexible (the conductor strands will not break when the wire is bent and straightened).
Unfortunately, today, due to the increase in the price of metals, including copper, some profiteers use metals such as CCA (aluminum or iron with a thin coating of copper) in the production of fake wire and cable.
Diagnosis ways:
Cutting the cross section of the wire and cable and checking the core color of the conductor strands, which should be copper in color, if using CCA, the core of the conductor strands is white.
Shaving the surface of the strands can ensure the color inside the conductor.
Flaring the conductor in such a way that it turns to ashes after applying the flame to the conductor due to its very low heat tolerance coefficient compared to copper.
Adhesion of insulation to coating:
At the time of removing the insulation from the coating, no adhesion should be observed because the existence of adhesion between the insulation and the coating indicates a non-standard wire and cable.
Frequently asked questions:
What causes wire and cable to become non-standard?
The high thickness of the insulation and cover in an unusual way compared to the cross section of the conductor, oxidation of the conductor, poor quality insulation and cover made of PVC
Why is the centrality of the conductor cross-section in the insulation and coating in the wire and cable standard very important?
The lack of centrality (center) of the conductor in the wire and coating causes the imbalance of the cross-section and the reduction of the thickness of the insulation in the wire and cables, causing tears in the insulation and coating, and the occurrence of fire or electric shock.
How to distinguish non-standard insulation and coating of wires and cables?
In most of the non-standard wires and cables, by applying low force, even by hand, their insulation and coating can be easily torn into pieces, or a piece of their surface can be scratched and separated with a nail.
This post is written by aak630