Saturday, July 21, 2012

The Composition Of Power Cables

There are companies involved in the manufacturing of power and control cables. A power cable is a kind of a system where electrical conductors are bound together with a sheath and this system or assembly is primarily utilized for transferring of electrical power. Power cables can be installed within buildings, exposed or run overhead as permanent wiring. Alternately, there is also an option of flexible power cables that can be used with mobile tools, portable devices and machinery and are even sometimes made out of PVC cables.

Power cables are available in an array of different types, materials and sizes and sometimes even insulated conductors that are quite large are also known as power cables. Power cables contain three important parts, which are conductors, insulation and jacket. The material used in the power cable and the way it is manufactured is dependent on the following factors:

1.The kind of working voltage will be the decisive factor for the thickness of the cable.
2.The kind of capacity it possesses for current-carrying will help in figuring out the size of the conductor.
3.Exposure to excess temperatures, chemicals, sunlight and mechanical impact are other factors that need to be taken into consideration to determine the type of outer jacket to be made.

Power cables are known to utilize aluminum or copper as conductors but sometimes smaller power cables may even use solid conductors. Cables that are specifically meant for exposed installations may also use wires wrapped around the cable, which becomes the metal armor to give it more strength and durability.

There are some cables that are used for overhead outdoors may not contain a sheath at all whereas there might be some other type of power cables that may use sheath made out of metal or plastic. It is important to ensure that the sheath material is resistant to oil, water, sunlight, chemicals, high temperatures as well as underground conditions. In some specific industries such as nuclear industry, there might be a requirement for the cable to possess requirements for radiation resistance. Cables that are specifically meant for underground use will generally have sheath made out of metal or plastic or even lead so that they are well protected.

In case of high voltages especially where the circuits operate above 2,000 volts, a conductive shield would need to surround the insulated conductor. This balances the stress applied by electricity on the cable insulation. Cables that are specifically meant for power distribution of 10kV or more can also be insulated with paper and oil and are usually made to pass through a semi-rigid aluminum, steel pipe or lead sheath. In case there is more high voltage, then oil has to be kept under pressure to stop any kind of void formations that would lead to discharge within the cable. Ideally most of the power cables available today use polyethylene or polymer, which also includes XLPE for further insulation.

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