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Pothead
A pothead is a type of insulated electrical terminal used for transitioning between overhead line and underground high-voltage cable or for connecting overhead wiring to equipment like transformers. Its name comes from the process of potting or encapsulation of the conductors inside the terminal's insulating bushing. Description Potheads are used where higher-voltage power lines go underground, generally voltages of 600 volts or greater. They are used mostly for service drops for commercial and industrial buildings. For lower voltages such as those used for residential service drops, another weather seal called a weatherhead is used. The device consists of a molded plastic housing that attaches to the end of an electrical conduit that carries the underground cables up the utility pole to the crossarm. Multiple bushing insulators project from the plastic body, each ending at an electrical terminal. Each overhead wire is connected to a bushing terminal from which the curr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pothead
A pothead is a type of insulated electrical terminal used for transitioning between overhead line and underground high-voltage cable or for connecting overhead wiring to equipment like transformers. Its name comes from the process of potting or encapsulation of the conductors inside the terminal's insulating bushing. Description Potheads are used where higher-voltage power lines go underground, generally voltages of 600 volts or greater. They are used mostly for service drops for commercial and industrial buildings. For lower voltages such as those used for residential service drops, another weather seal called a weatherhead is used. The device consists of a molded plastic housing that attaches to the end of an electrical conduit that carries the underground cables up the utility pole to the crossarm. Multiple bushing insulators project from the plastic body, each ending at an electrical terminal. Each overhead wire is connected to a bushing terminal from which the curr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weatherhead
A weatherhead, also called a weathercap, service head, service entrance cap, or gooseneck (slang) is a weatherproof service drop entry point where overhead power or telephone wires enter a building, or where wires transition between overhead and underground cables. At a building the wires enter a conduit, a protective metal pipe, and the weatherhead is a waterproof cap on the end of the conduit that allows the wires to enter without letting in water. It is shaped like a hood, with the surface where the wires enter facing down at an angle of at least 45°, to shield it from precipitation. A rubberized gasket makes for a tight seal against the wires. Before they enter the weatherhead, a ''drip loop'' is left in the overhead wires, which permits rain water that collects on the wires to drip off before reaching the weatherhead. A weatherhead termination is only used at low voltages (up to 600 volts), since higher distribution voltages require more insulation between conduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weatherhead
A weatherhead, also called a weathercap, service head, service entrance cap, or gooseneck (slang) is a weatherproof service drop entry point where overhead power or telephone wires enter a building, or where wires transition between overhead and underground cables. At a building the wires enter a conduit, a protective metal pipe, and the weatherhead is a waterproof cap on the end of the conduit that allows the wires to enter without letting in water. It is shaped like a hood, with the surface where the wires enter facing down at an angle of at least 45°, to shield it from precipitation. A rubberized gasket makes for a tight seal against the wires. Before they enter the weatherhead, a ''drip loop'' is left in the overhead wires, which permits rain water that collects on the wires to drip off before reaching the weatherhead. A weatherhead termination is only used at low voltages (up to 600 volts), since higher distribution voltages require more insulation between conduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-voltage Cable
A high-voltage cable (HV cable) is a cable used for electric power transmission at high voltage. A cable includes a conductor and insulation. Cables are considered to be fully insulated. This means that they have a fully rated insulation system that will consist of insulation, semi-con layers, and a metallic shield. This is in contrast to an overhead line, which may include insulation but not fully rated for operating voltage (EG: tree wire). High-voltage cables of differing types have a variety of applications in instruments, ignition systems, and alternating current (AC) and direct current (DC) power transmission. In all applications, the insulation of the cable must not deteriorate due to the high-voltage stress, ozone produced by electric discharges in air, or tracking. The cable system must prevent contact of the high-voltage conductor with other objects or persons, and must contain and control leakage current. Cable joints and terminals must be designed to control the high-vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bushing (electrical)
In electric power, a bushing is a hollow electrical insulator that allows an electrical conductor to pass safely through a conducting barrier such as the case of a transformer or circuit breaker without making electrical contact with it. Bushings are typically made from porcelain, though other insulating materials are also used. Explanation All materials carrying an electric charge generate an electric field. When an energized conductor is near a material at earth potential, it can form very high field strengths, especially where the field lines are forced to curve sharply around the earthed material. The bushing controls the shape and strength of the field and reduces the electrical stresses in the insulating material. Bushing condenser A bushing must be designed to withstand the electrical field strength produced in the insulation, when any earthed material is present. As the strength of the electrical field increases, leakage paths may develop within the insulation. If th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Breakdown
Electrical breakdown or dielectric breakdown is a process that occurs when an electrical insulating material, subjected to a high enough voltage, suddenly becomes an electrical conductor and electric current flows through it. All insulating materials undergo breakdown when the electric field caused by an applied voltage exceeds the material's dielectric strength. The voltage at which a given insulating object becomes conductive is called its breakdown voltage and in addition to its dielectric strength depends on its size and shape, and the location on the object at which the voltage is applied. Under sufficient electrical potential, electrical breakdown can occur within solids, liquids, or gases (and theoretically even in a vacuum). However, the specific breakdown mechanisms are different for each kind of dielectric medium. Electrical breakdown may be a momentary event (as in an electrostatic discharge), or may lead to a continuous electric arc if protective devices fail to int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Institute Of Electrical And Electronics Engineers
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operations center in Piscataway, New Jersey. The mission of the IEEE is ''advancing technology for the benefit of humanity''. The IEEE was formed from the amalgamation of the American Institute of Electrical Engineers and the Institute of Radio Engineers in 1963. Due to its expansion of scope into so many related fields, it is simply referred to by the letters I-E-E-E (pronounced I-triple-E), except on legal business documents. , it is the world's largest association of technical professionals with more than 423,000 members in over 160 countries around the world. Its objectives are the educational and technical advancement of electrical and electronic engineering, telecommunications, computer engineering and similar disciplines. History Origins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Creepage Distance
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 resistivit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Insulator
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] |
Cannabis (drug)
Cannabis, also known as marijuana among List of names for cannabis, other names, is a psychoactive drug from the cannabis plant. Native to Central or South Asia, the cannabis plant has been used as a drug for both Recreational marijuana, recreational and Entheogenic use of cannabis, entheogenic purposes and in various traditional medicines for centuries. Tetrahydrocannabinol (THC) is the main psychoactive component of cannabis, which is one of the 483 known compounds in the plant, including at least 65 other cannabinoids, such as cannabidiol (CBD). Cannabis can be used by Cannabis smoking, smoking, Vaporizer (inhalation device), vaporizing, Cannabis edible, within food, or Tincture of cannabis, as an extract. Cannabis has various effects of cannabis, mental and physical effects, which include euphoria, altered states of mind and Cannabis and time perception, sense of time, difficulty concentrating, Cannabis and memory, impaired short-term memory, impaired motor skill, body mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Conduit
An electrical conduit is a tube used to protect and route electrical wiring in a building or structure. Electrical conduit may be made of metal, plastic, fiber, or fired clay. Most conduit is rigid, but flexible conduit is used for some purposes. Conduit is generally installed by electricians at the site of installation of electrical equipment. Its use, form, and installation details are often specified by wiring regulations, such as the US National Electrical Code (NEC) and other building codes. History Some early electric lighting installations made use of existing gas pipe serving gas light fixtures which had been converted to electric lamps. Since this technique provided very good mechanical protection for interior wiring, it was extended to all types of interior wiring and by the early 20th century purpose-built couplings and fittings were manufactured for electrical use. However, most electrical codes now prohibit the routing of electrical conductors through gas piping ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Service Drop
In electric power distribution, a service drop is an overhead electrical line running from a utility pole, to a customer's building or other premises. It is the point where electric utilities provide power to their customers.Carson Dunlop "Electrical Systems" Dearborn Real Estate, 2003 page 24 The customer connection to an underground distribution system is usually called a "service lateral". Conductors of a service drop or lateral are usually owned and maintained by the utility company, but some industrial drops are installed and owned by the customer. At the customer's premises, the wires usually enter the building through a weatherhead that protects against entry of rain and snow, and drop down through conduit to an electric meter which measures and records the power used for billing purposes, then enters the main service panel. The utility's portion of the system ends, and the customer's wiring begins, at the output socket of the electric meter. The service panel will ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
