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Electric Switchboard
An electric switchboard is a piece of equipment that distributes electric power from one or more sources of supply to several smaller load circuits. It is an assembly of one or more panels, each of which contains switching devices for the protection and control of circuits fed from the switchboard. Several manufacturers make switchboards used in industry, commercial buildings, telecommunication facilities, oil and gas plants, data centers, health care, and other buildings, and onboard large ships. A switchboard is divided into different interconnected sections, generally consisting of a main section and a distribution section. These two sections are sometimes replaced by a combination section, which is a section that can fulfill the roles of both of the aforementioned sections. Switchboards can also sometimes come with an auxiliary section that is used to house devices that cannot be housed in the same section as other devices. Definition The U.S. National Electrical Code (NE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuse (electrical)
In electronics and electrical engineering, a fuse is an electrical safety device that operates to provide overcurrent protection of an electrical circuit. Its essential component is a metal wire or strip that melts when too much current flows through it, thereby stopping or interrupting the current. It is a sacrificial device; once a fuse has operated, it is an open circuit, and must be replaced or rewired, depending on its type. Fuses have been used as essential safety devices from the early days of electrical engineering. Today there are thousands of different fuse designs which have specific current and voltage ratings, breaking capacity, and response times, depending on the application. The time and current operating characteristics of fuses are chosen to provide adequate protection without needless interruption. Wiring regulations usually define a maximum fuse current rating for particular circuits. A fuse can be used to mitigate short circuits, overloading, mismatched loads ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tri-rated Cable
Tri-rated cable is a high temperature, flame retardant electrical wire designed for use inside electrical equipment. Tri-rated cable meets the requirements of three different international standards: BS 6231, UL 758, and CSA 22.2. Combining three standards in one product makes tri-rated cable suitable for use in equipment that is required to meet both North American and British wiring regulations. Construction Tri-rated cables are constructed with a flexible stranded copper conductor (Class 5 according to IEC 60228), and insulation of heat resistant PVC. Tri-rated cable is manufactured in a variety of insulation colours, including brown, orange, yellow, pink, and dark blue. Uses Tri-rated cable is designed for use in switch, control, relay and instrumentation panels of power circuits, and as internal connectors in rectifier equipment, motor starters and motor controllers. Standards BS 6231 BS 6231 is a British Standard, last revised in 2006 by the BSI Group. This standar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Enclosure
An electrical enclosure is a cabinet for electrical or electronic equipment to mount switches, knobs and displays and to prevent electrical shock to equipment users and protect the contents from the environment. The enclosure is the only part of the equipment which is seen by users. It may be designed not only for its utilitarian requirements, but also to be pleasing to the eye. Regulations may dictate the features and performance of enclosures for electrical equipment in hazardous areas, such as petrochemical plants or coal mines. Electronic packaging may place many demands on an enclosure for heat dissipation, radio frequency interference and electrostatic discharge protection, as well as functional, esthetic and commercial constraints. Standards Internationally, IEC 60529 classifies the IP Codes (ingress protection rating) of enclosures. In the United States, the National Electrical Manufacturers Association (NEMA) publishes NEMA enclosure type standards for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchroscope
In AC electrical power systems, a synchroscope is a device that indicates the degree to which two systems ( generators or power networks) are synchronized with each other.Terrell Croft, Wilford Summers (ed.), ''American Electricians' Handbook Eleventh Edition'', Mc Graw Hill, 1987 pp. 7-46 - 7-48 For two electrical systems to be synchronized, both systems must operate at the same frequency, and the phase angle between the systems must be zero (and two polyphase systems must have the same phase sequence). Synchroscopes measure and display the frequency difference and phase angle between two power systems. Only when these two quantities are zero is it safe to connect the two systems together. Connecting two unsynchronized AC power systems together is likely to cause high currents to flow, which will severely damage any equipment not protected by fuses or circuit breakers. Operating principles The simplest aid to synchronizing a generator to another system uses lamps wired betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AC Power
In an electric circuit, instantaneous power is the time rate of flow of energy past a given point of the circuit. In alternating current circuits, energy storage elements such as inductors and capacitors may result in periodic reversals of the direction of energy flow. Its SI unit is the watt. The portion of instantaneous power that, averaged over a complete cycle of the AC waveform, results in net transfer of energy in one direction is known as instantaneous active power, and its time average is known as active power or real power. The portion of instantaneous power that results in no net transfer of energy but instead oscillates between the source and load in each cycle due to stored energy is known as instantaneous reactive power, and its amplitude is the absolute value of reactive power. Active, reactive, apparent, and complex power in sinusoidal steady-state For a simple alternating current (AC) circuit in steady-state; consisting of a source and a Linear circuit, linear T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. The interval of time between events is called the period. It is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times per minute (2 hertz), its period is one half of a second. Special definitions of frequency are used in certain contexts, such as the angular frequency in rotational or cyclical properties, when the rate of angular progress is measured. Spatial frequency is defined for properties that vary or cccur repeatedly in geometry or space. The unit of measurement of frequency in the International System of Units (SI) is the hertz, having the symbol Hz. Definitions and units For cyclical phenomena such as oscillations, waves, or for examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Generator
In electricity generation, a generator, also called an ''electric generator'', ''electrical generator'', and ''electromagnetic generator'' is an electromechanical device that converts mechanical energy to electrical energy for use in an external circuit. In most generators which are rotating machines, a source of kinetic power rotates the generator's shaft, and the generator produces an electric current at its output terminals which flows through an external circuit, powering electrical loads. Sources of mechanical energy used to drive generators include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. Generators produce nearly all of the electric power for worldwide electric power grids. The first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. The reverse conversion of electrical energy into mechanical energy is done by an electric motor, and motors a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Injury
An electrical injury (electric injury) or electrical shock (electric shock) is damage sustained to the skin or internal organs on direct contact with an electric current. The injury depends on the density of the current, tissue resistance and duration of contact. Very small currents may be imperceptible or only produce a light tingling sensation. However, a shock caused by low and otherwise harmless current could startle an individual and cause injury due to jerking away or falling. A strong electric shock can often cause painful muscle spasms severe enough to dislocate joints or even to break bones. The loss of muscle control is the reason that a person may be unable to release themselves from the electrical source; if this happens at a height as on a power line they can be thrown off. Larger currents can result in tissue damage and may trigger ventricular fibrillation or cardiac arrest. If death results from an electric shock the cause of death is generally referred to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LV Switchboard
LV, Lv or lv may refer to: Arts and entertainment * Experience level or Level (video gaming), in video games and/or role-playing games * ''LV'' (album), a live EP by the rock band Chickenfoot Businesses and organizations * LEVEL (airline) (IATA code LV since 2017) * Albanian Airlines (IATA code LV, 1991–2011) * Lehigh Valley Railroad (AAR reporting mark LV) * Liverpool Victoria, an English friendly society, commonly known as ''LV='' * Louis Vuitton, a French fashion house People * Luther Vandross (1951–2005), American R&B singer and songwriter * L.V. (singer) (born 1960), American R&B singer * Lü (surname) (吕), a Chinese family name * LV (musical duo) (2007–present), electronic music duo Places * Las Vegas Valley the area in Nevada that includes ** Las Vegas, a city in Nevada ** The Las Vegas Strip ** other meanings see Las Vegas (other) * Latvia (ISO 3166 country code LV) * Lehigh Valley, an area in Pennsylvania Science and technology Biology and medicine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Current (electricity)
An electric current is a flow of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is defined as the net rate of flow of electric charge through a surface. The moving particles are called charge carriers, which may be one of several types of particles, depending on the conductor. In electric circuits the charge carriers are often electrons moving through a wire. In semiconductors they can be electrons or holes. In an electrolyte the charge carriers are ions, while in plasma, an ionized gas, they are ions and electrons. In the International System of Units (SI), electric current is expressed in units of ampere (sometimes called an "amp", symbol A), which is equivalent to one coulomb per second. The ampere is an SI base unit and electric current is a base quantity in the International System of Quantities (ISQ). Electric current is also known as amperage and is measured using a device called an ''ammeter''. Electric currents ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occupational Safety And Health Administration
The Occupational Safety and Health Administration (OSHA; ) is a regulatory agency of the United States Department of Labor that originally had federal visitorial powers to inspect and examine workplaces. The United States Congress established the agency under the Occupational Safety and Health Act (OSH Act), which President Richard Nixon, Richard M. Nixon signed into law on December 29, 1970. OSHA's mission is to "assure safe and healthy working conditions for working men and women by setting and enforcing standards and by providing training, outreach, education, and assistance." The agency is also charged with enforcing a variety of whistleblower statutes and regulations. OSHA's workplace safety inspections have been shown to reduce injury rates and injury costs without adverse effects on employment, sales, credit ratings, or firm survival. History The Bureau of Labor Standards of the Department of Labor has worked on some work safety issues since its creation in 1934. Economi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
