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Live-line Working
In electrical engineering, live-line working, also known as hotline maintenance, is the maintenance of electrical equipment, often operating at high voltage, while the equipment is energised. Although this is more hazardous for personnel than working on electrical equipment with the power off, live-line maintenance techniques are used in the electric power distribution industry to avoid the disruption and high economic costs of having to turn off power to customers to perform essential periodic maintenance on power line, transmission lines and other equipment. The first techniques for live-line working were developed in the early years of the 20th century, and both equipment and work methods were later refined to deal with increasingly higher voltages. In the 1960s, methods were developed in the laboratory to enable Lineworker, field workers to come into direct contact with high voltage lines. Such methods can be applied to enable safe work at the highest transmission voltages. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lineman Changing Transformer
Lineman or linesman may refer to: In personal roles: *Lineworker, one who installs and maintains electrical power, telephone, or telegraph lines *Lineman (gridiron football), a position in American football *Head linesman, the American football official in charge of the chain crew *Assistant referee (association football) or linesman *Linesmen, officials in ice hockey *Line umpire, an official in tennis In other uses: *Western Union splice or Lineman splice, a type of electrical wiring splice *"The Lineman", a song composed by Sam Spence for Associated Production Music * ''La Linea'' (TV series) or ''Lineman'', an Italian animated short series *Linesman/Mediator Air Defence RADAR system * Lineman (film), a 2024 Kannada-language comedy drama film See also *"Wichita Lineman "Wichita Lineman" is a 1968 song written by Jimmy Webb for American country music artist Glen Campbell, who recorded it backed by members of the Wrecking Crew. Widely covered by other artists, it has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Socket Wrench
A socket wrench (or socket spanner) is a type of spanner (or wrench in North American English) that uses a closed ''socket'' format, rather than a typical open wrench/spanner to turn a fastener, typically in the form of a nut or bolt. The most prevalent form is the ratcheting socket wrench, often informally called a ratchet. A ratchet incorporates a reversible ratcheting mechanism which allows the user to pivot the tool back and forth to turn its socket instead of removing and repositioning a wrench to do so. Other common methods of driving sockets include pneumatic impact wrenches, hydraulic torque wrenches, torque multipliers and breaker bars. Some lesser known hybrid drivers include striking wrench tools with square drive, and hydraulic impact wrenches (typically powered by on site hydraulic power such as present with military tanks, and many rail car applications). Interchangeable sockets The basic contemporary form of socket is hexagonal, referred to as "6-point" for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blindness
Visual or vision impairment (VI or VIP) is the partial or total inability of visual perception. In the absence of treatment such as corrective eyewear, assistive devices, and medical treatment, visual impairment may cause the individual difficulties with normal daily tasks, including reading and walking. The terms ''low vision'' and ''blindness'' are often used for levels of impairment which are difficult or impossible to correct and significantly impact daily life. In addition to the various permanent conditions, fleeting temporary vision impairment, amaurosis fugax, may occur, and may indicate serious medical problems. The most common causes of visual impairment globally are uncorrected refractive errors (43%), cataracts (33%), and glaucoma (2%). Refractive errors include near-sightedness, far-sightedness, presbyopia, and astigmatism (eye), astigmatism. Cataracts are the most common cause of blindness. Other disorders that may cause visual problems include age-related macular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arc Eye
Photokeratitis or ultraviolet keratitis is a painful eye condition caused by exposure of insufficiently protected eyes to the ultraviolet (UV) rays from either natural (e.g. intense direct or reflected sunlight) or artificial (e.g. the electric arc during welding) sources. Photokeratitis is akin to a sunburn of the cornea and conjunctiva. The injury may be prevented by wearing eye protection that blocks most of the ultraviolet radiation, such as welding goggles with the proper filters, a welder's helmet, sunglasses rated for sufficient UV protection, or appropriate snow goggles. The condition is usually managed by removal from the source of ultraviolet radiation, covering the corneas, and administration of pain relief. Photokeratitis is known by a number of different terms, including snow blindness, arc eye, welder's flash, sand eyes, bake eyes, corneal flash burns, flash burns, niphablepsia, or keratoconjunctivitis photoelectrica. Signs and symptoms Common symptoms include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. The photons of ultraviolet have greater energy than those of visible light, from about 3.1 to 12 electron volts, around the minimum energy required to ionize atoms. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack sufficient energy, it can induce chemical reactions and cause many substances to glow or fluoresce. Many practical applications, including chemical and biological effects, are derived from the way that UV radiation can interact with organic molecules. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders of Russia, land borders with fourteen countries. Russia is the List of European countries by population, most populous country in Europe and the List of countries and dependencies by population, ninth-most populous country in the world. It is a Urbanization by sovereign state, highly urbanised country, with sixteen of its urban areas having more than 1 million inhabitants. Moscow, the List of metropolitan areas in Europe, most populous metropolitan area in Europe, is the capital and List of cities and towns in Russia by population, largest city of Russia, while Saint Petersburg is its second-largest city and Society and culture in Saint Petersburg, cultural centre. Human settlement on the territory of modern Russia dates back to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASTM International
ASTM International, formerly known as American Society for Testing and Materials, is a standards organization that develops and publishes voluntary consensus technical international standards for a wide range of materials, products, systems and services. Some 12,575 apply globally. The headquarters is in West Conshohocken, Pennsylvania, about northwest of Philadelphia. It was founded in 1902 as the American Section of the International Association for Testing Materials. In addition to its traditional standards work, ASTM operates several global initiatives advancing additive manufacturing, advanced manufacturing, and emerging technologies, including the Additive Manufacturing Center of Excellence (AM CoE), the acquisition oWohlers Associatesfor market intelligence and advisory services, and the National Institute of Standards and Technology, NIST-funded Standardization Center of Excellence (SCOE). History In 1898, a group of scientists and engineers, led by chemist, industry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Faraday Cage
A Faraday cage or Faraday shield is an enclosure used to block some electromagnetic fields. A Faraday shield may be formed by a continuous covering of conductive material, or in the case of a Faraday cage, by a mesh of such materials. Faraday cages are named after scientist Michael Faraday, who first constructed one in 1836. Faraday cages work because an external electrical field will cause the electric charges within the cage's conducting material to be distributed in a way that cancels out the field's effect inside the cage. This phenomenon can be used to protect sensitive electronic equipment (for example RF receivers) from external radio frequency interference (RFI) often during testing or alignment of the device. Faraday cages are also used to protect people and equipment against electric currents such as lightning strikes and electrostatic discharges, because the cage conducts electrical current around the outside of the enclosed space and none passes through the interior. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rope Splicing
Rope splicing in ropework is the forming of a semi-permanent joint between two ropes or two parts of the same rope by partly untwisting and then interweaving their strands. Splices can be used to form a stopper at the end of a line, to form a loop or an eye in a rope, or for joining two ropes together. Splices are preferred to knotted rope, since while a knot typically reduces the strength by 20–40%, a splice is capable of attaining a rope's full strength. However, splicing usually results in a thickening of the line and, if subsequently removed, leaves a distortion of the rope. Most types of splices are used on three-strand rope, but some can be done on 12-strand or greater single-braided rope, as well as most double braids. While a spliced three-strand rope's strands are interwoven to create the splice, a braided rope's splice is constructed by simply pulling the rope into its jacket. Types of splice *Back splice (or end splice) – A splice where the strands of the end ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stockbridge Damper
A Stockbridge damper is a tuned mass damper used to suppress wind-induced vibrations on slender structures such as overhead power line An overhead power line is a structure used in electric power transmission and distribution to transmit electrical energy along large distances. It consists of one or more conductors (commonly multiples of three) suspended by towers or poles. ...s, long cantilevered signs and Cable-stayed bridge, cable-stayed bridges. The dumbbell-shaped device consists of two masses at the ends of a short length of cable or flexible rod, which is clamped at its middle to the main cable. The damper is designed to dissipate the energy of oscillations in the main cable to an acceptable level. Wind-induced oscillation Wind can generate three major modes of oscillation in suspended cables: * Conductor gallop, Gallop has an amplitude measured in metres and a frequency range of 0.08 to 3 Hz * Aeolian vibration (sometimes termed Aeroelastic flutter, flutter) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulator (electrical)
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 electrical conductor, 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 Nonmetal (chemistry), non-metals. A perfect insulator does not exist because even the materials used as 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 electrical breakdown, and the voltage at which it occurs is called the breakdown voltage of an insulator. Some materials such as glass, Electrical insulation paper, paper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
