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21 electric arc phenomenon
явление электрической дуги
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[Интент]Параллельные тексты EN-RU
Electric arc phenomenon
The electric arc is a phenomenon which takes place as a consequence of a discharge which occurs when the voltage between two points exceeds the insulating strength limit of the interposed gas; then, in the presence of suitable conditions, a plasma is generated which carries the electric current till the opening of the protective device on the supply side.
Gases, which are good insulating means under normal conditions, may become current conductors in consequence of a change in their chemical-physical properties due to a temperature rise or to other external factors.
To understand how an electrical arc originates, reference can be made to what happens when a circuit opens or closes.
During the opening phase of an electric circuit the contacts of the protective device start to separate thus offering to the current a gradually decreasing section; therefore the current meets growing resistance with a consequent rise in the temperature.
As soon as the contacts start to separate, the voltage applied to the circuit exceeds the dielectric strength of the air, causing its perforation through a discharge.
The high temperature causes the ionization of the surrounding air which keeps the current circulating in the form of electrical arc. Besides thermal ionization, there is also an electron emission from the cathode due to the thermionic effect; the ions formed in the gas due to the very high temperature are accelerated by the electric field, strike the cathode, release energy in the collision thus causing a localized heating which generates electron emission.
The electrical arc lasts till the voltage at its ends supplies the energy sufficient to compensate for the quantity of heat dissipated and to maintain the suitable conditions of temperature. If the arc is elongated and cooled, the conditions necessary for its maintenance lack and it extinguishes.
Analogously, an arc can originate also as a consequence of a short-circuit between phases. A short-circuit is a low impedance connection between two conductors at different voltages.
The conducting element which constitutes the low impedance connection (e.g. a metallic tool forgotten on the busbars inside the enclosure, a wrong wiring or a body of an animal entered inside the enclosure), subject to the difference of potential is passed through by a current of generally high value, depending on the characteristics of the circuit.
The flow of the high fault current causes the overheating of the cables or of the circuit busbars, up to the melting of the conductors of lower section; as soon as the conductor melts, analogous conditions to those present during the circuit opening arise. At that point an arc starts which lasts either till the protective devices intervene or till the conditions necessary for its stability subsist.
The electric arc is characterized by an intense ionization of the gaseous means, by reduced drops of the anodic and cathodic voltage (10 V and 40 V respectively), by high or very high current density in the middle of the column (of the order of 102-103 up to 107 A/cm2), by very high temperatures (thousands of °C) always in the middle of the current column and – in low voltage - by a distance between the ends variable from some microns to some centimeters.
[ABB]Явление электрической дуги
Электрическая дуга между двумя электродами в газе представляет собой физическое явление, возникающее в тот момент, когда напряжения между двумя электродами превышает значение электрической прочности изоляции данного газа.
При наличии подходящих условий образуется плазма, по которой протекает электрический ток. Ток будет протекать до тех пор, пока на стороне электропитания не сработает защитное устройство.
Газы, являющиеся хорошим изолятором, при нормальных условиях, могут стать проводником в результате изменения их физико-химических свойств, которые могут произойти вследствие увеличения температуры или в результате воздействия каких-либо иных внешних факторов.
Для того чтобы понять механизм возникновения электрической дуги, следует рассмотреть, что происходит при размыкании или замыкании электрической цепи.
При размыкании электрической цепи контакты защитного устройства начинают расходиться, в результате чего постепенно уменьшается сечение контактной поверхности, через которую протекает ток.
Сопротивление электрической цепи возрастает, что приводит к увеличению температуры.
Как только контакты начнут отходить один от другого, приложенное напряжение превысит электрическую прочность воздуха, что вызовет электрический пробой.
Высокая температура приведет к ионизации воздуха, которая обеспечит протекание электрического тока по проводнику, представляющему собой электрическую дугу. Кроме термической ионизации молекул воздуха происходит также эмиссия электронов с катода, вызванная термоэлектронным эффектом. Образующиеся под воздействием очень высокой температуры ионы ускоряются в электрическом поле и бомбардируют катод. Высвобождающаяся, в результате столкновения энергия, вызывает локальный нагрев, который, в свою очередь, приводит к эмиссии электронов.
Электрическая дуга длится до тех пор, пока напряжение на ее концах обеспечивает поступление энергии, достаточной для компенсации выделяющегося тепла и для сохранения условий поддержания высокой температуры. Если дуга вытягивается и охлаждается, то условия, необходимые для ее поддержания, исчезают и дуга гаснет.
Аналогичным образом возникает дуга в результате короткого замыкания электрической цепи. Короткое замыкание представляет собой низкоомное соединение двух проводников, находящихся под разными потенциалами.
Проводящий элемент с малым сопротивлением, например, металлический инструмент, забытый на шинах внутри комплектного устройства, ошибка в электромонтаже или тело животного, случайно попавшего в комплектное устройство, может соединить элементы, находящиеся под разными потенциалами, в результате чего через низкоомное соединение потечет электрический ток, значение которого определяется параметрами образовавшейся короткозамкнутой цепи.
Протекание большого тока короткого замыкания вызывает перегрев кабелей или шин, который может привести к расплавлению проводников с меньшим сечением. Как только проводник расплавится, возникает ситуация, аналогичная размыканию электрической цепи. Т. е. в момент размыкания возникает дуга, которая длится либо до срабатывания защитного устройства, либо до тех пор, пока существуют условия, обеспечивающие её стабильность.
Электрическая дуга характеризуется интенсивной ионизацией газов, что приводит к падению анодного и катодного напряжений (на 10 и 40 В соответственно), высокой или очень высокой плотностью тока в середине плазменного шнура (от 102-103 до 107 А/см2), очень высокой температурой (сотни градусов Цельсия) всегда в середине плазменного шнура и низкому падению напряжения при расстоянии между концами дуги от нескольких микрон до нескольких сантиметров.
[Перевод Интент]Тематики
- НКУ (шкафы, пульты,...)
EN
Англо-русский словарь нормативно-технической терминологии > electric arc phenomenon
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22 protection
1) защита; охрана; обеспечение безопасности2) крепление; ограждение3) гарантия•-
acoustic protection
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aircraft hijack protection
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anodic protection
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arc protection
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automatic overload protection
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average quality protection
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backup protection
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balance protection
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bank protection
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bilge protection
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boundary protection
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built-in power-supply protection
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built-in thermal protection
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busbar protection
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bus protection
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cabin glare protection
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carbon build-up protection
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carrier-current protection
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cathodic protection
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circuit breaker protection
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circulating-current pilot-wire differential protection
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coating protection
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collision protection
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computer protection
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contact protection
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copyright protection
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corrosion protection
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crossing protection
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cryptographic protection
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current protection
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damage protection
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data protection
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database protection
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definite-time graded relay protection
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definite-time graded protection
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differential protection
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digital distance protection
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digital overvoltage protection
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diode protection
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directional ground protection
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directional protection
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discrimination protection
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distance protection
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dual protection
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electrochemical protection
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encryption protection
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engine overspeed protection
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environmental protection
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error protection
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excess-voltage protection
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explosion protection
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external field protection
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falling voltage protection
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fault protection
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fetch protection
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field-failure protection
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field-winding protection
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file protection
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fire protection
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flag protection
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flood protection
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foam fire protection
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foam protection
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frost-heave protection
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galvanic protection
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gas protection
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ground fault protection
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ground overcurrent protection
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ground overvoltage protection
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hail protection
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head-on protection
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highlight overload protection
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high-speed protection
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high-voltage protection
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impedance protection
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implosion protection
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indoor protection
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interference protection
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interturn short-circuit protection
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intrusion protection
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inverse-definite-time current protection
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jamming protection
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lading protection
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leakage protection
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lightning protection
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lightning surge protection
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local backup protection
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longitudinal differential protection
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loss-of-field protection
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loss-of-synchronism protection
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lot quality protection
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low-voltage protection
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magnetic protection
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memory protection
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missiles protection
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negative phase-sequence protection
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negative sequence protection
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no-voltage protection
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no-volt protection
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open-phase protection
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opposing block protection
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outdoor protection
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out-of-step protection
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overall protection
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overcurrent protection
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overload protection
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overpower protection
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overspeed protection
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overvoltage protection
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oxide protection
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password protection
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percentage biased differential protection
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percentage differential protection
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phase overcurrent fault protection
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phase-comparison protection
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phase-failure protection
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phase-reversal protection
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physical protection
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pilot-wire protection
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points protection
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pole slipping protection
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positive phase-sequence protection
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positive sequence protection
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power protection
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power system relay protection
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power system protection
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power-down protection
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program protection
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protection of labor
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radiation protection
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radiological protection
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reactance protection
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reactor protection
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rear protection
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relay protection
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remote backup protection
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riprap protection
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roll-over protection
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rotor ground-fault protection
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rust protection
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sacrificial protection
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sandblasting protection
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scour protection
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sectionalizing protection
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selective protection
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shore protection
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short-circuit protection
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skid protection
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slip protection
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slope protection
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smoke protection
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spark protection
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static discharge protection
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stator short-circuit protection
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stepped current protection
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storage protection
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surge voltage protection
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surge protection
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switching error protection
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text security protection
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thermal overload protection
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thermal protection
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trailing protection
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transverse differential protection
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traveling-wave protection
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tripping protection
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unbalance protection
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undercurrent protection
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underfrequency protection
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undervoltage protection
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unequal error protection
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visibility protection
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water protection
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weather protection
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wheel slide protection
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work-site protection
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zerophase-sequence protection
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zerosequence protection -
23 corrosion
1. коррозия, разъедание2. размыв3. химическое растворение; химическая денудация; вымывание ( пород)— hydrogen-type corrosion
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коррозия, разъедание, ржавление
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1) коррозия; разъедание2) размыв3) химическое растворение; химическая денудация; вымывание ( пород)•corrosion at friction — коррозия при трении;
corrosion at initial boiling point — корродирующее действие нефтепродукта ( на медную пластинку) при начальной температуре его кипения;
corrosion at waterline — коррозия по ватерлинии;
corrosion by drilling mud — коррозия под действием бурового раствора;
corrosion by gases — газовая коррозия;
- acid corrosioncorrosion during distillation — корродирующее действие нефтепродукта ( на медную пластинку) в условиях его разгонки;
- active corrosion
- aeration corrosion
- aerobic corrosion
- alkaline corrosion
- anaerobic corrosion
- anodic corrosion
- aqueous corrosion
- ash corrosion
- atmospheric corrosion
- bacterial corrosion
- bimetallic corrosion
- biological corrosion
- blanket corrosion
- brine corrosion
- burned gas corrosion
- cathodic corrosion
- caustic corrosion
- cavitation corrosion
- chaffing corrosion
- channeling corrosion
- chemical corrosion
- chlorine corrosion
- concentration cell corrosion
- condensate corrosion
- contact corrosion
- continuous corrosion
- couple corrosion
- crevice corrosion
- current-stray corrosion
- damp atmospheric corrosion
- deep corrosion
- deposition corrosion
- differential corrosion
- differential aeration corrosion
- downhole corrosion
- down-the-hole corrosion
- drop corrosion
- dry atmospheric corrosion
- edge corrosion
- electrochemical corrosion
- electrolytic corrosion
- end corrosion
- equal-rate corrosion
- erosion corrosion
- exfoliation corrosion
- external corrosion
- extractive corrosion
- fatigue corrosion
- filiform corrosion
- fireside corrosion
- fluid corrosion
- fretting corrosion
- fuel corrosion
- full immersion corrosion
- full immersion honeycomb corrosion
- galvanic corrosion
- gaseous corrosion
- gas-phase corrosion
- gas-side corrosion
- general corrosion
- grain-boundary corrosion
- heavy local pitting corrosion
- high-temperature corrosion
- hot corrosion
- hot-salt corrosion
- hot-spot corrosion
- hydrogen corrosion
- hydrogen-evolution corrosion
- hydrogen-sulfide corrosion
- impingement corrosion
- indoor corrosion
- intercrystalline corrosion
- intergranular corrosion
- internal corrosion
- intragranular corrosion
- isolated corrosion
- knife-line corrosion
- layer corrosion
- leakage-current corrosion
- line corrosion
- local corrosion
- localized corrosion
- location-action corrosion
- marine corrosion
- massive corrosion
- meeting corrosion
- microbiological corrosion
- nonequal-rate corrosion
- nonuninform corrosion
- oil corrosion
- organogenic corrosion
- outdoor corrosion
- oxygen-adsorption corrosion
- partial impression corrosion
- patchy corrosion
- penetration corrosion
- pit corrosion
- pitch corrosion
- pitting corrosion
- pointed corrosion
- poultice corrosion
- radiolytic corrosion
- regional corrosion
- sacrificial corrosion
- seawater corrosion
- selective corrosion
- service corrosion
- self-sustaining corrosion
- slag corrosion
- soil corrosion
- sour crude corrosion
- sour oil corrosion
- spongious corrosion
- spot corrosion
- stray-current corrosion
- stress corrosion
- stress-free corrosion
- stressless corrosion
- structural corrosion
- sulfide corrosion
- sulfur corrosion
- sulfurated hydrogen corrosion
- surface corrosion
- sweet corrosion
- thermogalvanic corrosion
- through corrosion
- total surface corrosion
- transgranular corrosion
- trenching corrosion
- tubercular corrosion
- underground corrosion
- undermining corrosion
- undersurface corrosion
- underwater corrosion
- uniform corrosion
- vapor-phase corrosion
- variable immersion corrosion
- wet corrosion* * *• коррозия• размывАнгло-русский словарь нефтегазовой промышленности > corrosion
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24 impulse
1) импульс2) механический удар; толчок3) космонавт. включение ( двигательной установки)•-
angular impulse
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anodic impulse
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back impulse
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boosting impulse
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break impulse
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cathodic impulse
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chopped impulse
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current impulse
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direct impulse
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discharge impulse
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flow-rate impulse
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heat impulse
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incentive impulse
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lightning impulse
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line synchronizing impulses
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linear impulse
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lubrication impulse
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make impulse
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mark impulse
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normal impulse
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overlapping impulses
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pedestal impulse
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radial impulse
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reflected impulse
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required impulse
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sound impulse
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space impulse
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specific impulse
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steep current impulse
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switching impulse
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transverse impulse
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triangle impulse
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tripping impulse
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unit impulse
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velocity impulse
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voltage impulse -
25 coating
1) покрытие, нанесение покрытия2) плакирование3) покрытие; слой4) грунтовка7) кфт. нанесение эмульсионного слоя, полив ( эмульсии)8) эмалирование9) обшивка, облицовка10) рабочий слой ( магнитной ленты)12) пищ. глазирование13) глазурь14) дублирование ( тарного картона)•-
ablative coating
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absorbing coating
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acrylo-urethane coating
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adhering coating
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adhesive coating
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after vacuum coating
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alloy coating
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alloy-free coating
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aluminized coating
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anodic coating
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antidischarge coating
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antifouling coating
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antihalation coating
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antioxidizing coating
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antireflecting coating
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antireflection coating
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antiskid coating
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antistatic coating
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antiwear coating
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armored coating
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back coating
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bar coating
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barrier coating
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barrier-type coating
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base coating
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basic coating
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bisque coating
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bitumen coating
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black-chromium coating
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black-oxide coating
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blister coating
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bonded coating
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boron coating
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brass coating
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bright coating
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brush coating
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calender coating
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capacitor coating
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catalyst-cured coating
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cataphoretic coating
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cathodic coating
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cellular coating
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cermet coating
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chemical conversion coating
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chromium coating
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chromium diffusion coating
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chromium dioxide coating
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chromium-aluminum coating
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cladding coating
-
coating of ice
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cold end coating
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condenser coating
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copper coating
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cured coating
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current conducting coating
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curtain coating
-
dewetting coating
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diazo-photopolymer coating
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diffusion coating
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diffusion-inhibited coating
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dip coating
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direct-on coating
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double coating
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double-layer selective coating
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dry film coating
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duplex coating
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electrocatalytic coating
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electrochromic coating
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electrodeposited coating
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electrodeposited composite coating
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electrogalvanized coating
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electrolyte coating
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electrophoretic coating
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electroplated coating
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electrostatic coating
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emulsion coating of high quantum efficiency
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emulsion coating
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enamel coating
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engobe coating
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epoxy coating
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evaporation coating
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extrusion coating
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fiber coating
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fill-and-drain coating
-
film coating
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finishing coating
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flame-sprayed coating
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flash coating
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flow coating
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fluidized-bed coating
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fluorescent coating
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flux coating
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frosting coating
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full coating
-
fused coating
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galvanothermic coating
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gel coating
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gelatine coating
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glass coating
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glaze coating
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graphite coating
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grease coating
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heat-cured coating
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heat-reflective coating
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heat-seal coating
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heavy coating
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high-temperature coating
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hot end coating
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hot-dip coating
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hot-melt coating
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hydrophobic coating
-
immersion coating
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insulated coating
-
intermetallic compound coating
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ion-sputtering coating
-
lacquer coating
-
lead coating
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light-sensitive coating
-
lime fluorspar coating
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lining coating
-
low-emittance coating
-
luminescent coating
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magnetic coating
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matte coating
-
metal spray coating
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metallic coating
-
metal coating
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metal-backed coating
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metallized coating
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metal-oxide coating
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multiple coating
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negative working coating
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nitrid coating
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nonslip coating
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oil-adsorption coating
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optical coating
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over-the-ditch coating
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oxidation-resistant coating
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oxide coating
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pan coating
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paper coating
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pattern coating
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peelable coating
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photoelastic coating
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photoresist coating
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photosensitive coating
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photostress coating
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pickle-free coating
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piezoelectric coating
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pigment coating
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plasma coating
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plasma-deposited coating
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plasma-polymerized coating
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plasma-sprayed coating
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plastic coating
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plastic paper coating
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plastisol coating
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plate back coating
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polycomposite coating
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polymeric coating
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positive working coating
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powder coating
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prevent coating
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printed coating
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protective coating
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refractory coating
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release coating
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resist coating
-
resistant coating
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reverse roll coating
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rod coating
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roll coating
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roller coating
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rubber coating
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rust coating
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sacrificial coating
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sandwich coating
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selective coating
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self-bonded coating
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self-fluxing coating
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semimat coating
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sherardizing coating
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shielded arc coating
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slag coating
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slip coating
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spin-on coating
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spin coating
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sprayed coating
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spray coating
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strippable coating
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sulfide coating
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sull coating
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surface coating
-
tailored coating
-
terminating coating
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terne coating
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thermal barrier coating
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thermosetting coating
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tinned coating
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unbonded coating
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urethane coating
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vacuum coating
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varnish coating
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vitreous coating
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wave-length-shifting coating
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weight coating
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zinc coating -
26 electrosynthesis
электросинтез, электрохимический синтезelectrosynthesis at constant current — электросинтез при постоянном токе;Англо-русский словарь технических терминов > electrosynthesis
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27 cleaning
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28 cleaning
- anode cleaning
- anodic cleaning
- cathode cleaning
- cathodic cleaning
- electrolytic cleaning
- glow-discharge cleaning
- head cleaning
- ionic cleaning
- ionic-bombardment cleaning
- magnetic head cleaning
- nozzle cleaning
- reverse-current cleaning
- solvent cleaning
- ultrasonic cleaningThe New English-Russian Dictionary of Radio-electronics > cleaning
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См. также в других словарях:
anodic current — anodinė srovė statusas T sritis chemija apibrėžtis Elektronų pernaša iš elektrolito į elektrodą. atitikmenys: angl. anodic current rus. анодный ток … Chemijos terminų aiškinamasis žodynas
Anodic stripping voltammetry — is a voltammetric method for quantitative determination of specific ionic species. The analyte of interest is electroplated on the working electrode during a deposition step, and oxidized from the electrode during the stripping step. The current… … Wikipedia
anodic component of current — anodinė srovės dedamoji statusas T sritis chemija apibrėžtis Elektrodinės srovės algebrinės sumos teigiama dedamoji. atitikmenys: angl. anodic component of current rus. анодная составляющая тока … Chemijos terminų aiškinamasis žodynas
Cathodic current — Cathodic current, in electrochemistry, is the flow of electrons from the electrode interface to a species in solution.Anodic current is the flow of electrons into the electrode from a species in solution. References Bard, A.J. and Faulkner L.R.… … Wikipedia
Corrosion — v · d · e Materials failure modes Buckling · … Wikipedia
Cyclic voltammetry — Typical cyclic voltammogram where ipc and ipa show the peak cathodic and anodic current respectively for a reversible reaction. Cyclic voltammetry or CV is a type of potentiodynamic electrochemical measurement. In a cyclic voltammetry experiment… … Wikipedia
Charge transfer coefficient — Charge transfer coefficient, and symmetry factor (symbols α and β, respectively) are two related parameters used in description of the kinetics of electrochemical reactions. They appear in the Butler Volmer equation and related expressions. The… … Wikipedia
Cathode — Diagram of a copper cathode in a galvanic cell (e.g., a battery). A positive current i flows out of the cathode (CCD mnemonic: Cathode Current Departs). A cathode is an electrode through which electric current flows out of a polarized electrical… … Wikipedia
anodinė srovė — statusas T sritis chemija apibrėžtis Elektronų pernaša iš elektrolito į elektrodą. atitikmenys: angl. anodic current rus. анодный ток … Chemijos terminų aiškinamasis žodynas
анодный ток — anodinė srovė statusas T sritis chemija apibrėžtis Elektronų pernaša iš elektrolito į elektrodą. atitikmenys: angl. anodic current rus. анодный ток … Chemijos terminų aiškinamasis žodynas
анодный ток (в системе электрического дренажа) — — [Л.Г.Суменко. Англо русский словарь по информационным технологиям. М.: ГП ЦНИИС, 2003.] Тематики информационные технологии в целом EN anodic current … Справочник технического переводчика