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Insulating Link
An insulating link is a device used on the hook of a crane (machine), crane to protect the crane operatives from the danger of electrocution should the crane come into contact with a power line. Insulating links are essentially robust Insulator (electricity), insulators and prevent the flow of electricity from bare, suspended wires through cranes and into personnel working near the crane. Variants of insulating links are also made for specific use in antenna guy wires, and foundry and munitions applications. History The dangers of working near overhead power lines, which have no insulation covering their wires, first became apparent with the electrification of Western countries in the first half of the twentieth century. As early as 1931 there was a patent for an insulator that could be affixed to a crane’s wire rope or chain in order to prevent electrocution. Such early designs, however, proved unreliable because of their inability to operate safely in all construction crane en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crane (machine)
A crane is a type of machine, generally equipped with a hoist rope, wire ropes or chains, and sheaves, that can be used both to lift and lower materials and to move them horizontally. It is mainly used for lifting heavy objects and transporting them to other places. The device uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of a human. Cranes are commonly employed in transportation for the loading and unloading of freight, in construction for the movement of materials, and in manufacturing for the assembling of heavy equipment. The first known crane machine was the shaduf, a water-lifting device that was invented in ancient Mesopotamia (modern Iraq) and then appeared in ancient Egyptian technology. Construction cranes later appeared in ancient Greece, where they were powered by men or animals (such as donkeys), and used for the construction of buildings. Larger cranes were later developed in the Roman Empire, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrocution
Electrocution is death or severe injury caused by electric shock from electric current passing through the body. The word is derived from "electro" and "execution", but it is also used for accidental death. The term "electrocution" was coined in 1889 in the US just before the first use of the electric chair and originally referred to only electrical execution and not other electrical deaths. However, since no English word was available for non-judicial deaths due to electric shock, the word "electrocution" eventually took over as a description of all circumstances of electrical death from the new commercial electricity. Origins In the Netherlands in 1746 Pieter van Musschenbroek's lab assistant, Andreas Cuneus, received an extreme shock while working with a leyden jar, the first recorded injury from man-made electricity. By the mid-19th century high-voltage electrical systems came into use to power arc lighting for theatrical stage lighting and lighthouses leading to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Line
An overhead power line is a structure used in electric power transmission and distribution to transmit electrical energy across large distances. It consists of one or more uninsulated electrical cables (commonly multiples of three for three-phase power) suspended by towers or poles. Since most of the insulation is provided by the surrounding air, overhead power lines are generally the least costly method of power transmission for large quantities of electric energy. Construction Towers for support of the lines are made of wood either grown or laminated, steel or aluminum (either lattice structures or tubular poles), concrete, and occasionally reinforced plastics. The bare wire conductors on the line are generally made of aluminum (either plain or reinforced with steel or composite materials such as carbon and glass fiber), though some copper wires are used in medium-voltage distribution and low-voltage connections to customer premises. A major goal of overhead power line d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulator (electricity)
An electrical insulator is a material in which electric current does not flow freely. The atoms of the insulator have tightly bound electrons which cannot readily move. Other materials—semiconductors and conductors—conduct electric current more easily. The property that distinguishes an insulator is its resistivity; insulators have higher resistivity than semiconductors or conductors. The most common examples are non-metals. A perfect insulator does not exist because even insulators contain small numbers of mobile charges ( charge carriers) which can carry current. In addition, all insulators become electrically conductive when a sufficiently large voltage is applied that the electric field tears electrons away from the atoms. This is known as the breakdown voltage of an insulator. Some materials such as glass, paper and PTFE, which have high resistivity, are very good electrical insulators. A much larger class of materials, even though they may have lower bulk resistivity, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrification
Electrification is the process of powering by electricity and, in many contexts, the introduction of such power by changing over from an earlier power source. The broad meaning of the term, such as in the history of technology, economic history, and economic development, usually applies to a region or national economy. Broadly speaking, electrification was the build-out of the electricity generation and electric power distribution systems that occurred in Britain, the United States, and other now- developed countries from the mid-1880s until around 1950 and is still in progress in rural areas in some developing countries. This included the transition in manufacturing from line shaft and belt drive using steam engines and water power to electric motors. The electrification of particular sectors of the economy is called by terms such as ''factory electrification'', ''household electrification'', ''rural electrification'', ''aviation electrification'' or ''railway electrificati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Law
Federal law is the body of law created by the federal government of a country. A federal government is formed when a group of political units, such as states or provinces join in a federation, delegating their individual sovereignty and many powers to the central government while retaining or reserving other limited powers. As a result, two or more levels of government exist within an established geographic territory. The body of law of the common central government is the federal law. Examples of federal governments include those of Australia, Brazil, Canada, Germany, Malaysia, Pakistan, Republic of India, Russia, the former Soviet Union and the United States. Australia Brazil Canada Germany India Malaysia Pakistan Russia United States The United States Constitution established through the supremacy clause that the United States Constitution and federal law takes precedent over state law. These powers include the authority to govern international affairs, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Construction Industry
Construction is a general term meaning the art and science to form objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and comes from Latin ''constructio'' (from ''com-'' "together" and ''struere'' "to pile up") and Old French ''construction''. To construct is the verb: the act of building, and the noun is construction: how something is built, the nature of its structure. In its most widely used context, construction covers the processes involved in delivering buildings, infrastructure, industrial facilities and associated activities through to the end of their life. It typically starts with planning, financing, and design, and continues until the asset is built and ready for use; construction also covers repairs and maintenance work, any works to expand, extend and improve the asset, and its eventual demolition, dismantling or decommissioning. The construction i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground (electricity)
In electrical engineering, ground or earth is a reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the Earth. Electrical circuits may be connected to ground for several reasons. Exposed conductive parts of electrical equipment are connected to ground, to protect users from electrical shock hazard. If internal insulation fails, dangerous voltages may appear on the exposed conductive parts. Connecting exposed parts to ground will allow circuit breakers (or RCDs) to interrupt power supply in the event of a fault. In electric power distribution systems, a protective earth (PE) conductor is an essential part of the safety provided by the earthing system. Connection to ground also limits the build-up of static electricity when handling flammable products or electrostatic-sensitive devices. In some telegraph and power transmission circuits, the ground itself can be used as one condu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
