A power cable is an assembly of conductors wrapped inside a protective sheath. Power cables are used to conduct electricity from one point to another. Power cables are used today a ubiquitous part of our landscape, used for multiple purposes in different places — from domestic, industrial, agricultural to marine exploration.
Given the ever-increasing use of electronics across our world, the role of power cables manufacturers also becomes important. These manufacturers are akin to important builders of our world, producing components that connect our devices, give them the boost of power and help them run faster and more efficiently.
The first record of power cables into existence comes in 1844 when telegraph lines were strung between Washington D.C and Baltimore in Maryland, the USA for the first commercial telegraph network. These were very different from the power cables we see today. Made of iron, its surface was coated with sipper sulphate for a copper coating. This was intended to increase the lubrication of the otherwise difficult to use iron.
In the process, power cable manufacturers realized the copper’s superiority over iron in conducting electricity and soon copper replaced iron as conductors. Thomas Edison used these copper rods in 1882 to lay what would be the first power distribution system in New York City. The copper rods were wrapped in jute, which was then placed in a firm pipe that is filled with a bituminous compound.
Interestingly, vulcanized rubber had already made its appearance, but it wasn’t used in power cable manufacturing till 1897 when it was used for the 11,000 volt-circuit in the Niagara Falls power project. Till the late 1800s, commercial cable manufacturing was still using mass impregnated paper for insulation. Many other materials were experimented with for manufacturing the power cables, such as cloth-covered cables, saturating cloth asphalt and finally rubber insulation.
Armored cables were introduced in 1906. These cables carried two rubber-insulated conductors, which were cloth covered. The big advantage here was the flexible sheathing. These cables were flexible and more efficient, but they were more expensive than their predecessors. PVC appeared as insulation for cables in the 1930s and by the end of the World War II, different types of synthetic rubbers had made their appearance.
The use of PVC for commercial power cable manufacturing became commonplace only after its manufacturing was made commercially feasible in the 1950s. It replaced rubber, which was more commonly used till then. This was also the time when aluminium emerged as an alternative to copper for conductors, even though copper is a superior conductor.
However, it was only in the 1970s that XLPE started emerging as a more viable insulating material, replacing paper. The use of different materials in the construction of a power cable is still evolving as we find new elements and properties that we can play with.
Evolution of the power cables
The history of power cable evolution is also the story of mankind striving for perfection, of finding the product that will do what nature never intended us to do — harness to power of electrons and then take it wherever we want. This is a tough job and so, we have taken decades, running into more than a century, to perfect the part. Power cable manufacturers are continuously working to re-invent the simple core design and its construction because their applications have become more complex than ever.
As the man tries to conquer all terrains and domains, our cables have to keep up. So, we are laying cables underground, immersing it is water and expecting these to withstand immense temperature, moisture and weather fluctuations. As a result, we are now making cables that are designed to be resistant to almost anything, even the outer space. The range of appliances/equipment: The sheer complexity of our equipment, gadgets and appliances has brought in their own change. On the face of it, a power cable’s requirement is simply to supply power, but as the appliances and their use become complex, so does the cables. For instance, we now need flexible cables that can handle coiling and tension. We need cables that can carry information as well as power in a network.
The history of power cable manufacturing mirrors our own journey towards technological supremacy. With each new development, the power cable manufacturers have made our electronic tools run more efficiently and effectively.