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Encyclopedia > Ground (electricity)
Image:Signal Ground.svg Image:Chassis Ground.svg Image:Earth Ground.svg
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Ground symbols

The term ground or earth usually means a common return path in electrical circuits. The terms Earth return and ground return are also common. Image File history File links Please see the file description page for further information. ... The ground conductor is an electric conductorable rope on the top of pylons. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... An electrical network or electrical circuit is an interconnection of analog electrical elements such as resistors, inductors, capacitors, diodes, switches and transistors. ...

Contents

Different types of ground

Main article: Ground conductor

In electrical engineering, the term ground or earth has a few meanings depending on the specific application areas. The ground conductor is an electric conductorable rope on the top of pylons. ... Electrical Engineers design power systems… … and complex electronic circuits. ...


In radio frequency communications

Fig. 1: A metal stake earth connection (left of gray conduit) at a residential home in Australia. Note the green and yellow marked earth wire.
Fig. 1: A metal stake earth connection (left of gray conduit) at a residential home in Australia. Note the green and yellow marked earth wire.

An electrical connection to earth for as a reference potential for radio frequency antenna signals. The part directly in contact with the earth (the earth electrode) can be as simple as a metal rod or stake driven into the earth (Fig. 1), or a connection to buried metal water piping (though this carries the risk of the water pipe being later replaced with plastic). Because high frequency signals can flow to earth through capacitance, capacitance to ground is an important factor in effectiveness of signal grounds. Because of this a complex system of buried rods and wires can be effective. An ideal signal ground maintains zero voltage regardless of how much electrical current flows into ground or out of ground. The resistance at the signal frequency of the electrode-to-earth connection determines its quality, and that quality is improved by increasing the surface area of the electrode in contact with the earth, increasing the depth to which it is driven, using several connected ground rods, increasing the moisture of the soil, improving the conductive mineral content of the soil, and increasing the land area covered by the ground system. Image File history File linksMetadata Download high-resolution version (2048x1536, 659 KB) Summary Photo taken by en:User:Ali K on 22 March 2006. ... Image File history File linksMetadata Download high-resolution version (2048x1536, 659 KB) Summary Photo taken by en:User:Ali K on 22 March 2006. ... An electrical connection between discrete points allows the flow of electrons, (current). ... It has been suggested that this article or section be merged with Radio waves. ... In electricity, current is the rate of flow of charges, usually through a metal wire or some other electrical conductor. ... Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ...


In AC power wiring installations

In a mains (AC power) wiring installation, the ground is a wire with an electrical connection to earth, that provides an alternative path to the ground for heavy currents that might otherwise flow through a victim of electric shock. This power ground grounding wire is (directly or indirectly) connected to one or more earth electrodes. These may be located locally, be far away in the suppliers network or in many cases both. This grounding wire is usually but not always connected to the neutral wire at some point and they may even share a cable for part of the system under some conditions. The ground wire is also usually bonded to pipework to keep it at the same potential as the electrical ground during a fault. Water supply pipes often used to be used as ground electrodes but this was banned in some countries when plastic pipe such as PVC became popular. This type of ground applies to radio antennas and to lightning protection systems. Ground or earth in a mains (AC power) electrical wiring system is a conductor that exists primarily to help protect against faults and which in normal operation does not carry current. ... A water supply system provides water to the locations that need it. ... PVC may refer to the following: Polyvinyl chloride, a plastic Premature ventricular contraction, irregular heartbeat Permanent virtual circuit, a term used in telecommunications and computer networks Param Vir Chakra, Indias highest military honor. ...


In electronics

Circuit ground versus earth

In an electrical circuit operating at signal voltages (usually less than 50 V or so), a common return path is the zero voltage reference level for the equipment or system. Voltage is a differential quantity, which appears between two points having some electrical potentials. In order to deal only with a voltage (an electrical potential) of a single point, the second point has to be connected to a reference point (ground) having usually zero voltage. This signal ground may or may not actually be connected to a power ground. A system where the system ground is not actually connected to earth is often referred to as a floating ground. An electrical network or electrical circuit is an interconnection of analog electrical elements such as resistors, inductors, capacitors, diodes, switches and transistors. ... A signal within the context of circuit theory is any information that has value to a particular electronic network. ... International safety symbol Caution, risk of electric shock (ISO 3864), colloquially known as high voltage symbol. ... Electrical potential is the potential energy per unit charge associated with a static (time-invariant) electric field, also called the electrostatic potential or the electric potential, typically measured in volts. ... The word ground has several meanings: The surface of the Earth Soil, a mixture of sand and organic material present on the surface of the Earth Ground (electricity), in electrical engineering, something that is connected to the Earth or at the voltage defined as zero (in the US, called ground... Single-ended signalling is the simplest method of transmitting electrical signals over wires. ... For uses of the term ground or earth in electricity but outside of mains wiring please see Ground (electricity) Ground or earth in a mains (AC power) electrical wiring system is a core that exists primarily to help protect against faults. ...


Separating low signal ground from a noisy ground

In television stations, recording studios, and other installations where sound quality is critical, a special signal ground known as a "technical ground" (or "technical earth") is often installed. This is basically the same thing as an AC power ground, but no appliance ground wires are allowed any connection to it, as they may carry electrical interference. In most cases, the studio's metal equipment racks are all joined together with heavy copper cables (or flattened copper tubing or busbars) and similar connections are made to the technical ground. Great care has to be taken that nobody places any AC-grounded appliances (heaters etc) on the racks, as a single AC ground connection to the technical ground will destroy its effectiveness. For particularly demanding applications, the main technical ground may consist of a heavy copper pipe, if necessary fitted by drilling through several concrete floors, so they can all be connected by the shortest possible path to a grounding rod in the basement. With the recent proliferation of digital studios with massive audio channel capacity (up to 512 channels), the installation of high-quality audio grounding has become mandatory, as any ground-introduced interference tends to be cumulative. Noise levels that were perfectly satisfactory for old 24-channel studios may become intolerable with ten or twenty times that number. A recording studio is a facility for sound recording. ... Single-ended signalling is the simplest method of transmitting electrical signals over wires. ... 1500 amp busbars within a power distribution rack for a large building A busbar (often pronounced buzz bar) refers in electrical power distribution to thick strips of Copper or other material that conduct electricity around a switchboard or distribution board. ...


In electrical shielding

An electrical connection to the inside surface of a Faraday cage serves as an example of an electrical shielding. Any excess charges deposited on the inner surface of a Faraday cage will migrate to the outer surface of the cage, where they can produce no electric fields within the enclosure. For this reason, the inside surface of a Faraday cage behaves like an infinite sink for electrical charge from the perspective of objects within. Even if the Faraday cage itself is not connected to the Earth, the inner surface of the cage can be used in place of an earth connection. Entrance to a Faraday room A Faraday cage or Faraday shield is an enclosure formed by conducting material, or by a mesh of such material. ... It has been suggested that optical field be merged into this article or section. ... Electric charge is a fundamental property of some subatomic particles, which determines their electromagnetic interactions. ...


In lightning protection

A ground conductor on a lightning protection system is used to dissipate the strike into the earth. A lightning ground conductor (also known as an earth conductor, "grounding conductor", "equipment grounding conductor", "earth ground" "ground" "protective earth conductor" and many other names) is an electrically conductive wire or cable, typically green or green with a yellow stripe or even bare copper. The ground conductor is an electric conductorable rope on the top of pylons. ...


Uses

A power ground serves to provide a return path for fault currents and therefore allows the fuse or breaker to disconnect the circuit. The power ground is also often bonded to the house's incoming pipework, and pipes and cables entering the bathroom are sometimes cross-bonded. This is done to try to reduce the voltage between objects that can be touched simultaneously. Filters also connect to the power ground, but this is mainly to stop the power ground carrying noise into the systems which the filters protect, rather than as a direct use of the power ground. See: NEC (Article 250). For uses of the term ground or earth in electricity but outside of mains wiring please see Ground (electricity) Ground or earth in a mains (AC power) electrical wiring system is a core that exists primarily to help protect against faults. ... The National Electric Code Handbook, 2005 edition The National Electrical Code (NEC), or NFPA 70, is a standard for the safe installation of electrical wiring and equipment. ...


In Single Wire Earth Return (SWER) electrical distribution systems, costs are saved by using just a single high voltage conductor for the power grid, while routing the AC return current through the earth. This system is mostly used in rural areas where large earth currents will not otherwise cause hazards. Single wire earth return (SWER) or single wire ground return is a single-wire transmission line for supplying single-phase electrical power to remote areas at low cost. ... Description of an electrical power grid Electrical power is generated in many locations and created by various technologies in the form of alternating current. ...


Signal grounds serve as return paths for signals and power at low voltages (less than about 50 V) within equipment, and on the signal interconnections between equipment. Many electronic designs feature a single return that acts as a reference for all signals. Power and signal grounds often get connected together, usually through the metal case of the equipment. Lightning protection is a very specialised form of grounding used in an attempt to divert the huge currents from lightning strikes.


Grounding is primarily used for safety to prevent electric shock or fires caused by a voltage potential between the earth and a conductor such as an appliance cabinet or chassis. Grounding is often used to conduct lightning strikes harmlessly to earth rather than starting fires and damaging equipment. It is also used to control electrical noise in computer, audio and video, and communications circuits. This illustrates that an electrical ground should have an appropriate current-carrying capability in order to serve as an adequate zero-voltage reference level.


History

Long-distance electromagnetic telegraph systems from 1820 onwards used two or more wires to carry the signal and return currents. It was then discovered, probably by the German scientist Carl August Steinheil in 1836-1837 [1], that the ground could be used as the return path to complete the circuit, making the return wire unnecessary. However, there were problems with this system, exemplified by the transcontinental telegraph line constructed in 1861 by the Western Union Company between Saint Joseph, Missouri, and Sacramento, California. During dry weather, the ground connection often developed a high resistance, requiring water to be poured on the ground rod to enable the telegraph to work or phones to ring. Optical Telegraf of Claude Chappe on the Litermont near Nalbach, Germany Telegraphy (from the Greek words tele (τηλε) = far and graphein (γραφειν) = write) is the long-distance transmission of written messages without physical transport of letters, originally by changing something that could be observed from a distance (optical telegraphy). ... 1820 was a leap year starting on Saturday (see link for calendar). ... Carl August von Steinheil was a French physicist who is known for several different inventions. ... Year 1836 (MDCCCXXXVI) was a leap year starting on Friday (link will display the full calendar) of the Gregorian Calendar (or a leap year starting on Wednesday of the 12-day slower Julian calendar). ... Queen Victoria, Queen of the United Kingdom (1837 - 1901) 1837 (MDCCCXXXVII) was a common year starting on Sunday (see link for calendar). ... 1861 (MDCCCLXI) was a common year starting on Tuesday (link with display the full calendar) of the Gregorian calendar (or a common year starting on Thursday of the Julian calendar) // January 1 - Benito Juárez captures Mexico City January 2 - Friedrich Wilhelm IV of Prussia dies and is succeeded by... This article does not cite any references or sources. ... Location of Sacramento in California County Sacramento Government  - Mayor Heather Fargo Area  - City  99. ...


Later, when telephony began to replace telegraphy, it was found that the currents in the earth induced by power systems, electrical railways, other telephone and telegraph circuits, and natural sources including lightning caused unacceptable interference to the audio signals, and the two-wire system was reintroduced.


See also

Ground conductors
Ground mat, Domestic AC power plugs and sockets, Earthing systems
Other
Ground constants, Virtual ground, Ground loop, Phantom circuit, Phantom loop,

The ground conductor is an electric conductorable rope on the top of pylons. ... A ground mat or grounding mat is a flat, flexible pad used for working on electrostatic sensitive devices. ... This information has been proof read by Robert Selbie of Sydney Grammar School and is pronouced false. ... // In electricity supply systems, an earthing system defines the electrical potential of the conductors relative to that of the Earths conductive surface. ... In telecommunication, ground constants are the electrical parameters of earth, such as conductivity, permittivity, and magnetic permeability. ... Virtual ground (sometimes called virtual earth) is a very important concept found in electronic circuit designs. ... In an electrical system, ground loop refers to an unwanted current that flows in a conductor connecting two points that are nominally at the same potential, ground, but are actually at different potentials. ... In telecommunication and electrical engineering, a phantom circuit is a circuit derived from suitably arranged wires with one or more conductive paths being a circuit in itself and at the same time acting as one conductor of another circuit. ... A phantom loop is an electrical network that uses part of the natural environment to complete a circuit. ...

Source

Federal Standard 1037C, entitled Telecommunications: Glossary of Telecommunication Terms is a United States Federal Standard, issued by the General Services Administration pursuant to the Federal Property and Administrative Services Act of 1949, as amended. ... MIL-STD-188 is a series of U.S. military standards relating to telecommunications. ...

External links

  • The Electromagnetic Telegraph, by J. B. Calvert
  • Grounding for Low- and High- Frequency Circuits (PDF) — Analog Devices Application Note
  • An IC Amplifier User’s Guide to Decoupling, Grounding, and Making Things Go Right for a Change (PDF) — Analog Devices Application Note

  Results from FactBites:
 
Ground loop (electricity) - Wikipedia, the free encyclopedia (656 words)
In an electrical system, ground loop refers to a current, generally unwanted, in a conductor connecting two points that are supposed to be at the same potential, that is, ground, but are actually at different potentials.
In a floating ground system, that is, one not connected to Earth, the voltages will probably be unstable, and if some of the conductors that constitute the return circuit to the source have a relatively high resistance, or have, flowing through them, high currents that produce a significant voltage (I·R) drop can be hazardous.
In this case the video cable is grounded at the projector end to the home electrical system, and at the other end to the cable TV's ground, inducing a current through the cable which distorts the picture.
Ground (electricity) - Wikipedia, the free encyclopedia (979 words)
The ground wire is also usually bonded to pipework to keep it at the same potential as the electrical ground during a fault.
In an electrical circuit operating at signal voltages (usually less than 50 V or so), a common return path that is the zero voltage reference level for the equipment or system.
Grounding is primarily used for safety to prevent electric shock or fires caused by a voltage potential between the earth and a conductor such as an appliance cabinet or chassis.
  More results at FactBites »

 
 

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