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Mineral-insulated copper-clad cable is a variety of electrical cable made from copper conductors inside a copper sheath, insulated by inorganic magnesium oxide powder. The name is often abbreviated to MICC or MI cable, and colloquially known as pyro (because the original manufacturer and vendor for this product in the UK was a company called ...
A grounded wire is sometimes strung along the tops of the towers to provide lightning protection. An optical ground wire is a more advanced version with embedded optical fibers for communication. Overhead wire markers can be mounted on the ground wire to meet International Civil Aviation Organization recommendations. [7]
A hunk of copper is visible that is designed to be easily connected or disconnected from its place between two screws, rated for 600 A (as stamped on it). We also see the thick wires in standard colors (two yellow/green ground and two blue neutral), as well as markings PEN (protected earth and neutral), PE (protective earth) and N (neutral).
An OPGW cable was patented by BICC in 1977 [1] and installation of optical ground wires became widespread starting in the 1980s. In the peak year of 2000, around 60,000 km of OPGW was installed worldwide. Asia, especially China, has become the largest regional market for OPGW used in transmission-line construction. [3]
Above-ground lines cost around $10 per 1-foot (0.30 m) and underground lines cost in the range of $20 to $40 per 1-foot (0.30 m). [10] In highly urbanized areas, the cost of underground transmission can be 10–14 times as expensive as overhead. [11] However, these calculations may neglect the cost of power interruptions.
An example of a copper alloy conductor is cadmium copper wire, which is used for railroad electrification in North America. [5] In Britain the BPO (later Post Office Telecommunications ) used cadmium copper aerial lines with 1% cadmium for extra strength; for local lines 40 lb/mile (1.3 mm dia) and for toll lines 70 lb/mile (1.7 mm dia).
The electrodes for electrical grounding are often called ground rods and are often made from steel with a copper clad surface – typically 1 to 2 m long and 20 millimetres (0.79 in) in diameter. These are driven vertically into the ground and bonded together with bare copper wire . [ 1 ]
Power cables use stranded copper or aluminum conductors, although small power cables may use solid conductors in sizes of up to 1/0. (For a detailed discussion on copper cables, see: Copper wire and cable.). The cable may include uninsulated conductors used for the circuit neutral or for ground (earth) connection.