Grand Coulee Dam
Grand Coulee Dam is a concrete gravity dam on the Columbia River in the U. S. state of Washington, built to provide irrigation water. Constructed between 1933 and 1942, Grand Coulee had only two powerhouses; the third powerhouse, completed in 1974 to increase energy production, makes Grand Coulee the largest power station in the United States by nameplate-capacity at 6,809 MW. The proposal to build the dam was the focus of a bitter debate during the 1920s between two groups. One group wanted to irrigate the ancient Grand Coulee with a gravity canal while the other pursued a high dam and pumping scheme; the dam supporters won in 1933, but for fiscal reasons the initial design was for a "low dam" 290 feet tall which would generate electricity without supporting irrigation. That year, the U. S. Bureau of Reclamation and a consortium of three companies called. After visiting the construction site in August 1934, President Franklin Delano Roosevelt endorsed the "high dam" design which, at 550 ft high, would provide enough electricity to pump water into the Columbia basin for irrigation.
Congress approved the high dam in 1935 and it was completed in 1942. The first waters overtopped Grand Coulee's spillway on June 1 of that year. Power from the dam fueled the growing industries of the Northwest United States during World War II. Between 1967 and 1974, the third powerplant was constructed; the decision to construct the additional facility was influenced by growing energy demand, regulated river flows stipulated in the Columbia River Treaty with Canada, competition with the Soviet Union. Through a series of upgrades and the installation of pump-generators, the dam now supplies four power stations with an installed capacity of 6,809 MW; as the centerpiece of the Columbia Basin Project, the dam's reservoir supplies water for the irrigation of 671,000 acres. The reservoir is called Franklin Delano Roosevelt Lake, named after the United States President who presided over the dam's authorization and completion. Creation of the reservoir forced the relocation of over 3,000 people, including Native Americans whose ancestral lands were flooded.
While the dam does not contain fish passage, neither does the next downstream dam, Chief Joseph Dam. This means no salmon reach the Grand Coulee Dam; the second large dam downstream, Rocky Reach Dam, has an intricate system of fish ladders to accommodate yearly salmon spawning and migration. The Grand Coulee is an ancient river bed on the Columbia Plateau created during the Pliocene Epoch by retreating glaciers and floods. Geologists believed a glacier that diverted the Columbia River formed the Grand Coulee, but it was revealed in the mid-late 20th century that massive floods from Lake Missoula carved most of the gorge; the earliest known proposal to irrigate the Grand Coulee with the Columbia River dates to 1892, when the Coulee City News and The Spokesman Review reported on a scheme by a man named Laughlin McLean to construct a 1,000 ft dam across the Columbia River, high enough that water would back up into the Grand Coulee. A dam that size would have its reservoir encroach into Canada. Soon after the Bureau of Reclamation was founded, it investigated a scheme for pumping water from the Columbia River to irrigate parts of central Washington.
An attempt to raise funds for irrigation failed in 1914, as Washington voters rejected a bond measure. In 1917, William M. Clapp, a lawyer from Ephrata, proposed the Columbia be dammed below the Grand Coulee, he suggested a concrete dam could flood the plateau, just as nature blocked it with ice centuries ago. Clapp was joined by James O'Sullivan, another lawyer, by Rufus Woods, publisher of The Wenatchee World newspaper in the nearby agricultural centre of Wenatchee. Together, they became known as the "Dam College". Woods began promoting the Grand Coulee Dam in his newspaper with articles written by O'Sullivan; the dam idea gained popularity with the public in 1918. Backers of reclamation in Central Washington split into two camps; the "pumpers" favored a dam with pumps to elevate water from the river into the Grand Coulee from which canals and pipes could irrigate farmland. The "ditchers" favored diverting water from northeast Washington's Pend Oreille River via a gravity canal to irrigate farmland in Central and Eastern Washington.
Many locals such as Woods, O'Sullivan and Clapp were pumpers, while many influential businessmen in Spokane associated with the Washington Water and Power Company were staunch ditchers. The pumpers argued that hydroelectricity from the dam could cover costs and claimed the ditchers sought to maintain a monopoly on electric power; the ditchers took several steps to ensure support for their proposals. In 1921, WWPC secured a preliminary permit to build a dam at Kettle Falls, about 110 mi upstream from the Grand Coulee. If built, the Kettle Falls Dam would have lain in the path of the Grand Coulee Dam's reservoir blocking its construction. WWPC planted rumors in the newspapers, stating exploratory drilling at the Grand Coulee site found no granite on which a dam's foundations could rest, only clay and fragmented rock; this was disproved with Reclamation-ordered drilling. Ditchers hired engineer of the Panama Canal, to prepare a report. Goethals produced a report backing the ditchers; the Bureau of Reclamation was unimpressed by Goethals' report.
In July 1923, President Warren G. Harding visited Washington state and expressed support for irrigation work there, but died a month later, his successor, Calvin Coolidge, had little interest in irriga
Sweden the Kingdom of Sweden, is a Scandinavian Nordic country in Northern Europe. It borders Norway to the west and north and Finland to the east, is connected to Denmark in the southwest by a bridge-tunnel across the Öresund, a strait at the Swedish-Danish border. At 450,295 square kilometres, Sweden is the largest country in Northern Europe, the third-largest country in the European Union and the fifth largest country in Europe by area. Sweden has a total population of 10.2 million. It has a low population density of 22 inhabitants per square kilometre; the highest concentration is in the southern half of the country. Germanic peoples have inhabited Sweden since prehistoric times, emerging into history as the Geats and Swedes and constituting the sea peoples known as the Norsemen. Southern Sweden is predominantly agricultural, while the north is forested. Sweden is part of the geographical area of Fennoscandia; the climate is in general mild for its northerly latitude due to significant maritime influence, that in spite of this still retains warm continental summers.
Today, the sovereign state of Sweden is a constitutional monarchy and parliamentary democracy, with a monarch as head of state, like its neighbour Norway. The capital city is Stockholm, the most populous city in the country. Legislative power is vested in the 349-member unicameral Riksdag. Executive power is exercised by the government chaired by the prime minister. Sweden is a unitary state divided into 21 counties and 290 municipalities. An independent Swedish state emerged during the early 12th century. After the Black Death in the middle of the 14th century killed about a third of the Scandinavian population, the Hanseatic League threatened Scandinavia's culture and languages; this led to the forming of the Scandinavian Kalmar Union in 1397, which Sweden left in 1523. When Sweden became involved in the Thirty Years War on the Reformist side, an expansion of its territories began and the Swedish Empire was formed; this became one of the great powers of Europe until the early 18th century. Swedish territories outside the Scandinavian Peninsula were lost during the 18th and 19th centuries, ending with the annexation of present-day Finland by Russia in 1809.
The last war in which Sweden was directly involved was in 1814, when Norway was militarily forced into personal union. Since Sweden has been at peace, maintaining an official policy of neutrality in foreign affairs; the union with Norway was peacefully dissolved in 1905. Sweden was formally neutral through both world wars and the Cold War, albeit Sweden has since 2009 moved towards cooperation with NATO. After the end of the Cold War, Sweden joined the European Union on 1 January 1995, but declined NATO membership, as well as Eurozone membership following a referendum, it is a member of the United Nations, the Nordic Council, the Council of Europe, the World Trade Organization and the Organisation for Economic Co-operation and Development. Sweden maintains a Nordic social welfare system that provides universal health care and tertiary education for its citizens, it has the world's eleventh-highest per capita income and ranks in numerous metrics of national performance, including quality of life, education, protection of civil liberties, economic competitiveness, equality and human development.
The name Sweden was loaned from Dutch in the 17th century to refer to Sweden as an emerging great power. Before Sweden's imperial expansion, Early Modern English used Swedeland. Sweden is derived through back-formation from Old English Swēoþēod, which meant "people of the Swedes"; this word is derived from Sweon/Sweonas. The Swedish name Sverige means "realm of the Swedes", excluding the Geats in Götaland. Variations of the name Sweden are used in most languages, with the exception of Danish and Norwegian using Sverige, Faroese Svøríki, Icelandic Svíþjóð, the more notable exception of some Finnic languages where Ruotsi and Rootsi are used, names considered as referring to the people from the coastal areas of Roslagen, who were known as the Rus', through them etymologically related to the English name for Russia; the etymology of Swedes, thus Sweden, is not agreed upon but may derive from Proto-Germanic Swihoniz meaning "one's own", referring to one's own Germanic tribe. Sweden's prehistory begins in the Allerød oscillation, a warm period around 12,000 BC, with Late Palaeolithic reindeer-hunting camps of the Bromme culture at the edge of the ice in what is now the country's southernmost province, Scania.
This period was characterised by small bands of hunter-gatherer-fishers using flint technology. Sweden is first described in a written source in Germania by Tacitus in 98 AD. In Germania 44 and 45 he mentions the Swedes as a powerful tribe with ships that had a prow at each end. Which kings ruled these Suiones is unknown, but Norse mythology presents a long line of legendary and semi-legendary kings going back to the last centuries BC; as for literacy in Sweden itself, the runic script was in use among the south Scandinavian elite by at least the 2nd century AD, but all that has come down to the present from the Roman Period is curt inscriptions on artefacts of male names, demonstrating th
An electrical connector is an electro-mechanical device used to join electrical terminations and create an electrical circuit. Electrical connectors consist of jacks; the connection may be temporary, as for portable equipment, require a tool for assembly and removal, or serve as a permanent electrical joint between two wires or devices. An adapter can be used to bring together dissimilar connectors. Hundreds of types of electrical connectors are manufactured for power and control applications. Connectors may join two lengths of flexible copper wire or cable, or connect a wire or cable to an electrical terminal. In computing, an electrical connector can be known as a physical interface. Cable glands, known as cable connectors in the US, connect wires to devices mechanically rather than electrically and are distinct from quick-disconnects performing the latter. Electrical connectors are characterised by their pinout and physical construction, contact resistance, insulation between pins and resistance to vibration, resistance to entry of water or other contaminants, resistance to pressure, reliability and ease of connecting and disconnecting.
They may be keyed to prevent insertion in the wrong orientation, connecting the wrong pins to each other, have locking mechanisms to ensure that they are inserted and cannot work loose or fall out. Some connectors are designed such that certain pins make contact before others when inserted, break first on disconnection, it is desirable for a connector to be easy to identify visually, rapid to assemble, require only simple tooling, be inexpensive. In some cases an equipment manufacturer might choose a connector because it is not compatible with those from other sources, allowing control of what may be connected. No single connector has all the ideal properties. Fretting is a common failure mode in electrical connectors that have not been designed to prevent it. Many connectors are keyed, with some mechanical component which prevents mating except with a oriented matching connector; this can be used to prevent incorrect or damaging interconnections, either preventing pins from being damaged by being jammed in at the wrong angle or fitting into imperfectly fitting plugs, or to prevent damaging connections, such as plugging an audio cable into a power outlet.
For instance, XLR connectors have a notch to ensure proper orientation, while Mini-DIN plugs have a plastic projection, which fits into a corresponding hole in the socket and prevent different connectors from being pushed together. Some connector housings are designed with locking mechanisms to prevent inadvertent disconnection or poor environmental sealing. Locking mechanism designs include locking levers of various sorts, screw locking, toggle or bayonet locking. Depending on application requirements, housings with locking mechanisms may be tested under various environmental simulations that include physical shock and vibration, water spray, etc. to ensure the integrity of the electrical connection and housing seals. A terminal is a simple type of electrical connector that connects two or more wires to a single connection point. Wire nuts are another type of single point connector. Terminal blocks provide a convenient means of connecting individual electrical wires without a splice or physically joining the ends.
They are used to connect wiring among various items of equipment within an enclosure or to make connections among individually enclosed items. Since terminal blocks are available for a wide range of wire sizes and terminal quantity, they are one of the most flexible types of electrical connector available; some disadvantages are that connecting wires is more difficult than plugging in a cable and the terminals are not well protected from contact with persons or foreign conducting materials. One type of terminal block accepts wires that are prepared only by removing a short length of insulation from the end. Another type accepts wires that have spade terminal lugs crimped onto the wires. Printed circuit board mounted terminal blocks allow individual wires to be connected to the circuit board. PCB mounted terminal blocks are soldered to the board, but they are available in a pull-apart version that allows the wire-connecting half of the block to be unplugged from the part, soldered to the PCB.
A general type of connector that screws or clamps bare wire to a post. Many, but not all binding posts will accept a banana connector plug. Crimp-on connectors are a type of solderless connection. Since stripping the insulation from wires is time-consuming, many connectors intended for rapid assembly use insulation-displacement connectors so that insulation need not be removed from the wire; these take the form of a fork-shaped opening in the terminal, into which the insulated wire is pressed and which cut through the insulation to contact the conductor within. To make these connections reliably on a production line, special tools are used which control the forces applied during assembly. If properly assembled, the resulting terminations are gas-tight and will last the life of the product. A common example is the multi
Coaxial cable, or coax is a type of electrical cable that has an inner conductor surrounded by a tubular insulating layer, surrounded by a tubular conducting shield. Many coaxial cables have an insulating outer sheath or jacket; the term coaxial comes from the outer shield sharing a geometric axis. Coaxial cable was invented by English engineer and mathematician Oliver Heaviside, who patented the design in 1880. Coaxial cable is a type of transmission line, used to carry high frequency electrical signals with low losses, it is used in such applications as telephone trunklines, broadband internet networking cables, high speed computer data busses, carrying cable television signals, connecting radio transmitters and receivers to their antennas. It differs from other shielded cables because the dimensions of the cable and connectors are controlled to give a precise, constant conductor spacing, needed for it to function efficiently as a transmission line. Coaxial cable is used as a transmission line for radio frequency signals.
Its applications include feedlines connecting radio transmitters and receivers to their antennas, computer network connections, digital audio, distribution of cable television signals. One advantage of coaxial over other types of radio transmission line is that in an ideal coaxial cable the electromagnetic field carrying the signal exists only in the space between the inner and outer conductors; this allows coaxial cable runs to be installed next to metal objects such as gutters without the power losses that occur in other types of transmission lines. Coaxial cable provides protection of the signal from external electromagnetic interference. Coaxial cable conducts electrical signal using an inner conductor surrounded by an insulating layer and all enclosed by a shield one to four layers of woven metallic braid and metallic tape; the cable is protected by an outer insulating jacket. The shield is kept at ground potential and a signal carrying voltage is applied to the center conductor; the advantage of coaxial design is that electric and magnetic fields are restricted to the dielectric with little leakage outside the shield.
Conversely and magnetic fields outside the cable are kept from interfering with signals inside the cable. Larger diameter cables and cables with multiple shields have less leakage; this property makes coaxial cable a good choice for carrying weak signals that cannot tolerate interference from the environment or for stronger electrical signals that must not be allowed to radiate or couple into adjacent structures or circuits. Common applications of coaxial cable include video and CATV distribution, RF and microwave transmission, computer and instrumentation data connections; the characteristic impedance of the cable is determined by the dielectric constant of the inner insulator and the radii of the inner and outer conductors. In radio frequency systems, where the cable length is comparable to the wavelength of the signals transmitted, a uniform cable characteristic impedance is important to minimize loss; the source and load impedances are chosen to match the impedance of the cable to ensure maximum power transfer and minimum standing wave ratio.
Other important properties of coaxial cable include attenuation as a function of frequency, voltage handling capability, shield quality. Coaxial cable design choices affect physical size, frequency performance, power handling capabilities, flexibility and cost; the inner conductor might be stranded. To get better high-frequency performance, the inner conductor may be silver-plated. Copper-plated steel wire is used as an inner conductor for cable used in the cable TV industry; the insulator surrounding the inner conductor may be solid plastic, a foam plastic, or air with spacers supporting the inner wire. The properties of the dielectric insulator determine some of the electrical properties of the cable. A common choice is a solid polyethylene insulator, used in lower-loss cables. Solid Teflon is used as an insulator; some coaxial lines have spacers to keep the inner conductor from touching the shield. Many conventional coaxial cables use braided copper wire forming the shield; this allows the cable to be flexible, but it means there are gaps in the shield layer, the inner dimension of the shield varies because the braid cannot be flat.
Sometimes the braid is silver-plated. For better shield performance, some cables have a double-layer shield; the shield might be just two braids, but it is more common now to have a thin foil shield covered by a wire braid. Some cables may invest in more than two shield layers, such as "quad-shield", which uses four alternating layers of foil and braid. Other shield designs sacrifice flexibility for better performance; those cables cannot be bent as the shield will kink, causing losses in the cable. When a foil shield is used a small wire conductor incorporated into the foil makes soldering the shield termination easier. For high-power radio-frequency transmission up to about 1 GHz, coaxial cable with a solid copper outer conductor is available in sizes of 0.25 inch upward. The outer conductor is corrugated like a bellows to permit flexibility and the inner conductor is held in position by a plastic spiral to approximate an air dielectric. One brand name for such cable is Heliax. Coaxial cables require an internal structure of an insulating material to maintain the spacing between the center conductor and shield.
A power supply is an electrical device that supplies electric power to an electrical load. The primary function of a power supply is to convert electric current from a source to the correct voltage and frequency to power the load; as a result, power supplies are sometimes referred to as electric power converters. Some power supplies are separate standalone pieces of equipment, while others are built into the load appliances that they power. Examples of the latter include power supplies found in desktop computers and consumer electronics devices. Other functions that power supplies may perform include limiting the current drawn by the load to safe levels, shutting off the current in the event of an electrical fault, power conditioning to prevent electronic noise or voltage surges on the input from reaching the load, power-factor correction, storing energy so it can continue to power the load in the event of a temporary interruption in the source power. All power supplies have a power input connection, which receives energy in the form of electric current from a source, one or more power output connections that deliver current to the load.
The source power may come from the electric power grid, such as an electrical outlet, energy storage devices such as batteries or fuel cells, generators or alternators, solar power converters, or another power supply. The input and output are hardwired circuit connections, though some power supplies employ wireless energy transfer to power their loads without wired connections; some power supplies have other types of inputs and outputs as well, for functions such as external monitoring and control. Power supplies are categorized including by functional features. For example, a regulated power supply is one that maintains constant output voltage or current despite variations in load current or input voltage. Conversely, the output of an unregulated power supply can change when its input voltage or load current changes. Adjustable power supplies allow the output voltage or current to be programmed by mechanical controls, or by means of a control input, or both. An adjustable regulated power supply is one, both adjustable and regulated.
An isolated power supply has a power output, electrically independent of its power input. Power supplies are classified accordingly. A bench power supply is a stand-alone desktop unit used in applications such as circuit test and development. Open frame power supplies have only a partial mechanical enclosure, sometimes consisting of only a mounting base. Rack mount. An integrated power supply is one. An external power supply, AC adapter or power brick, is a power supply located in the load's AC power cord that plugs into a wall outlet; these are popular in consumer electronics because of their safety. Power supplies can be broadly divided into linear and switching types. Linear power converters process the input power directly, with all active power conversion components operating in their linear operating regions. In switching power converters, the input power is converted to AC or to DC pulses before processing, by components that operate predominantly in non-linear modes. Power is "lost" when components operate in their linear regions and switching converters are more efficient than linear converters because their components spend less time in linear operating regions.
A DC power supply is one. Depending on its design, a DC power supply may be powered from a DC source or from an AC source such as the power mains. DC power supplies use AC mains electricity as an energy source; such power supplies will employ a transformer to convert the input voltage to a higher or lower AC voltage. A rectifier is used to convert the transformer output voltage to a varying DC voltage, which in turn is passed through an electronic filter to convert it to an unregulated DC voltage; the filter removes most, but not all of the AC voltage variations. The electric load's tolerance of ripple dictates the minimum amount of filtering that must be provided by a power supply. In some applications, high ripple is tolerated and therefore no filtering is required. For example, in some battery charging applications it is possible to implement a mains-powered DC power supply with nothing more than a transformer and a single rectifier diode, with a resistor in series with the output to limit charging current.
In a switched-mode power supply, the AC mains input is directly rectified and filtered to obtain a DC voltage. The resulting DC voltage is switched on and off at a high frequency by electronic switching circuitry, thus producing an AC current that will pass through a high-frequency transformer or inductor. Switching occurs at a high frequency, thereby enabling the use of transformers and filter capacitors that are much smaller and less expensive than those found in linear power supplies operating at mains frequency. After the inductor or transformer secondary, the high frequency AC is rectified and filtered to pr
Flexible cables, or'continuous-flex' cables, are electrical cables specially designed to cope with the tight bending radii and physical stress associated with moving applications, such as inside cable carriers. Due to increasing demands within the field of automation technology in the 1980s, such as increasing loads, moving cables guided inside cable carriers failed, although the cable carriers themselves did not. In extreme cases, failures caused by "corkscrews" and core ruptures brought entire production lines to a standstill, at high cost; as a result, specialized flexible cables were developed with unique characteristics to differentiate them from standard designs. These are sometimes called "chain-suitable," "continuous flex" cables. A higher level of flexibility means the service life of a cable inside a cable carrier can be extended. A normal cable manages 50,000 cycles, but a dynamic cable can complete between one and three million cycles. Flexible cables can be divided into two types: those with conductors stranded in layers inside the cable, those that have bundled or braided conductors.
Stranding in layers is easier to produce, therefore less expensive. The cable cores are stranded and left long in several layers around the center and are enclosed in an extruded tube shaped jacket. In the case of shielded cables, the cores are wrapped up with fleece or foils. However, this type of construction means that, during the bending process, the inner radius compresses and the outer radius stretches as the cable core moves; this works quite well, because the elasticity of the material is still sufficient, but material fatigue can set in and cause permanent deformations. The cores move and begin to make their own compressing and stretching zones, which can lead to a “corkscrew” shape, core rupture; the unique cable construction technique of braiding conductors around a tension-proof centre instead of layering them is the second type of construction. Eliminating multi-layers guarantees a uniform bend radius across each conductor. At any point where the cable flexes, the path of any core moves from the inside to the outside of the cable.
The result is that no single core compresses near the inside of the bend or stretches near the outside of the bend—which reduces overall stresses. An outer jacket is still required to prevent the cores untwisting. A pressure filled; this ensures that the cores can not untwist. The resulting dynamic cable is stiffer than a standard cable, but lasts longer in applications where it must flex. List of flexible cable suppliers Another list from the Kellysearch industrial directory
Cable management refers to management of electrical or optical cable in a cabinet or an installation. The term is used for products, planning. Cables can become tangled, making them difficult to work with, sometimes resulting in devices accidentally becoming unplugged as one attempts to move a cable; such cases are known as "cable spaghetti", any kind of problem diagnosis and future updates to such enclosures could be difficult. Cable management both supports and contains cables during installation, makes subsequent maintenance or changes to the cable system easier. Products such as cable trays, cable ladders, cable baskets are used to support a cable through cabling routes; the choice of cables is important. Color-coding of cables is sometimes used to keep track of, which. For instance, the wires coming out of ATX power supplies are color-coded by voltage. Documenting and labeling cable runs, tying related cables together by cable ties, cable lacing, rubber bands or other means, running them through cable guides, clipping or stapling them to walls are other common methods of keeping them organized.
Above drop ceilings, hooks or trays are used to organize cables and protect them from electrical interference Planning is crucial for cables such as Thicknet that do not bend around corners and fiber optic, difficult to splice once cut. Cable strain relief is a mechanical protection for flexible electrical cables, wires and pneumatic hoses, it is regulated by the European standard EN 62444. With a strain relief component, the connection between a flexible electrical line and its connection port is protected against mechanical stress; the lines are fixed by clamping them into single cable clamps made of plastic or metal. Another possibility is to use so called cord grips which consist of weaved wire strands that put a grip around the cables. A more cable-friendly alternative is attaching the lines to special strain relief plates using common cable ties. In case of industrial applications these strain relief plates are as well cost-effective because the packing density is much higher than with common cable clamps which are designed for holding one single line.
Furthermore, most of the available cable clamps are not flexible when it comes to routing lines with varying diameters. That causes higher storage costs; the installation of the single cable clamps can take a lot of mounting time, depending on the laying length of the lines. Strain relief plates are therefore a more flexible solution which allows a parallel routing of several lines with varying diameters. Strain relief is required for terminated electrical lines that are plugged into sockets or ports to prevent unplugging or accidentally ripping out of the connector. At which point the lines have to be strain relieved depends on the application. For PROFINET, for example, used in automation it is recommended to set the strain relief component approx. 1 m / 3.5 ft from the connection point. Strain relief components are used in applications where cables and hoses are exposed to constant dynamic stress. One end of a cable is terminated in the data cabinet; the other end of a cable ends at the desk.
The cable management needs at either end. Buildings and office furniture are designed with cable management in mind; some cables have requirements for minimum bend radius or proximity to other cables power cables, to avoid crosstalk or interference. Power cables need to be grouped separately and suitably apart from data cables, only cross at right angles which minimizes electromagnetic interference; the organized routing of cables inside the computer case allows for optimal cooling. Good cable management makes working inside a computer much easier by providing safer hardware installation, repair, or removal; some PC mod enthusiasts showcase the internal components of their systems with a window mod, which displays the aesthetics of internal cabling as well as the skills and wealth of the modder. The IT industry needs data cables to be added, moved, or removed many times during the life of the installation, it is usual practice to install "fixed cables" between cabling cabinets. These cables are contained in cable trays etc. and are terminated at each end onto patch panels in the communications cabinet or outlets at the desktop.
The circuits are interconnected to the final destination using patch cords. Because large IT infrastructures encompass vast networks of cables -- all of which need to be serviced, added, so on throughout an installation lifecycle -- cable planning, in some fashion, is a necessity. Techs may employ different methods of cable planning, depending upon the level of detail required for proper management. Excel can be employed for organizing information, however techs need a way to visually organize information, which goes beyond Excel’s capabilities. For proper visualization of cabling, companies may opt to use a cable management software package. In hospital situations, cable management can be critical to preventing medical mistakes. Emergency room nurse manager Pat Gabriel said, "My wish is that we could somehow not have spaghetti on the bed; when you look