How an electrical cable is made
Would you like to know how an electrical cable is made?
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We are surrounded by electrical cables. We have become so used to it that we hardly notice them. However, if we didn't have them, daily tasks such as switching on a light in a room, using a lift, or turning on a computer wouldn't be possible. The cables come in different types and sizes, which makes it possible to supply electricity to this printer, or make a wind-turbine work.
The technology needed to ensure an electrical cable stays in good working condition for several years without problems involves complicated manufacturing processes which require highly qualified staff.
THE PROCESS OF CREATING AN ELECTRICAL CABLE:
1. CONDUCTOR 2. INSULATION 3. Screen if required 4. Assembly 5. Inner COVERINGS 6. Armoring 7. OUTER SHEATH 8. QUALITY CONTROL 9. SHIPPING 10. SUSTAINABILITY
The basic components of an electrical cable are the conductor and the insulation. The conductor channels the current through the cable and the insulation maintains the flow of electricity in the conductor. Cables may also have other additional coverings to protect them and increase their working life.
The most frequently used material for the conductor in an electrical cable is copper. Aluminium is also used in specific cases.
The first manufacturing process of a conductor is the wire-drawing. This consists of reducing the diameter of the copper wire gradually to its final diameter to increase its ductility and conductivity and decrease the skin effect
The copper arrives from the foundry to the manufacturer's factories in large coils weighing 5 tonnes. This copper, 8 mm in diameter, is technically known as "wire rod".
The first stage of the wire-drawing is simply called, "drawing". The diameter of the wire rod is reduced to 2 mm during this process.
This 2-mm wire is then drawn further to reduce the diameter of the wire to the size needed for each kind of conductor.
In the last stage of wire-drawing, all the wires undergo a heat treatment called annealing. The aim of this stage is to increase the ductility and conductivity of the copper as in drawing stages cooper loss some of its conductivity during reducing the diameter from 8 mm to the specified wire diameter
After the wire-drawing, the copper wires are grouped together to make conductors. This process is called stranding.
During the wiring process, conductors with different cross-sections are made. For example, a cross-section as small as 0.5 mm2 to 240 mm2, 400 mm2 or even higher for larger current capacities.
The machine used to make the cables depends on the cross-section of each conductor.
The next process in the manufacture of electrical cables is the insulation. This is when we place an insulating cover over the conductor to prevent current leakages.
In this process, the insulating material is added by a process of extrusion at high temperature. The insulation ensures there are no current leakages. Several insulating materials may be used: PVC, EPR, XLPE, etc.
Different insulation materials may be used depending on the characteristics of the cable required. The quality of an insulation material depends on two basic characteristics: its insulation capacity and its heat resistance.
The material's insulation capacity and its thickness determine the cable's maximum service voltage.
An insulation material with a high heat resistance allows the conductor to transmit more power than the same cross-section with an insulation with a lower heat resistance.
The whole length of the cable undergoes a voltage test to ensure the insulation layer does not have any faults.
Phase wiring is the grouping of different insulated conductors to make a multicore cable on assembly machines.
The phases can be identified by colour or by numbering them, check HD standard HD 308 for colors and IEC 60502
A voltage test is also carried out on the whole length of the manufactured cable during this process.
And that is how an electrical cable is made.
However, in some cases, the cable may require additional elements in order to improve its protection or operation.
Electrical coverings, also called "screens", insulate the signals that circulate in the cable from possible external interference. They also shield the power cables to prevent them from interfering with adjacent signal circuits.
Mechanical coverings, also called "armour", protect the cable from external damage that may occur from knocks, rodents, and any other potential causes of damage.. The armour is made from steel or aluminium and can come in the form of metal strips, wires or braids.
Cables usually have an outer polymer covering for protection. This is called the "outer-sheath". This sheath protects the conductors and their insulation from external elements which may change their electrical properties, such as moisture. It also protects them from mechanical aggresion, which may occur during the installation of the cable.
As with the insulation, the outer-sheath can be made from a thermoplastic or a thermosetting plastic.
The outer-sheath is applied like the insulation via a process of extrusion at high temperature. The sheath may be made from different materials depending on the required protection level, the final flexibility of the cable, the work environment, etc. As example : PVC, LLDPE, MDPE, HDPE, LSHF, EPR, ...etc
So that all Top Cable customers can correctly identify their cables, the cables are marked with the most important information: Manufacturer, trade name, cable name, number of conductors, cross-section, construction regulation and standards, CE marking and other information of interest, such as the product's certification. There is also a meter by meter mark on the cable to help our customers with their stock control.
A voltage test is also carried out on the whole length of the manufactured cable during this process.
And that is how an electrical cable is manufactured. But the process does not finish here. The manufacturer verifies the quality of all cables by carrying out rigorous checks before they are sold.
In order to guarantee the high quality required by Top Cable's customers, the cables undergo extensive quality control checks in our laboratories, therefore ensuring that all the cables are free from defects and are ready to be sold and this according to each type and international standrads IEC 60502-1, IEC 60227, BS 6004, ..etc
The quality guarantee systems, approved according to the ISO 9001 regulation are applied during all the manufacturing stages and guarantee that the cables will work perfectly.
Orders are managed at our different logistics centres and then they are shipped out to our customers. Our advanced Warehouse Management System (WMS) provides us with information about the stock status at Top Cable's logistics centres at all times, guaranteeing the availability of the product and allowing us to meet the tightest deadlines.
We have created recycling systems at all Top Cable's manufacturing centres for the waste produced during the manufacture of electrical cables.
All waste, both from scrap cable and waste produced during the manufacturing process is delivered to specialised companies to be correctly disposed of. This is how we guarantee that the environmental impact of our industrial activity is kept to a minimum.
