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1 ток проводимости
- Stromstärke, (elektrische)
- Leitungsstromstärke
- (elektrische) Stromstärke
ток проводимости
Явление направленного движения свободных носителей электрического заряда в веществе или в пустоте, количественно характеризуемое скалярной величиной, равной производной по времени от электрического заряда, переносимого свободными носителями заряда сквозь рассматриваемую поверхность.
[ ГОСТ Р 52002-2003]EN
(electric) current
(conduction) current
scalar quantity equal to the flux of the electric current density J through a given directed surface S:
where endA is the vector surface element
NOTE 1 – The electric current through a surface is equal to the limit of the quotient of the electric charge transferred through that surface during a time interval by the duration of this interval when this duration tends to zero.
NOTE 2 – For charge carriers confined to a surface, the electric current is defined through a curve of this surface (see the note to term “lineic electric current”).
[IEV number 121-11-13]FR
courant (électrique), m
courant (de conduction), m
grandeur scalaire égale au flux de la densité de courant électrique J à travers une surface orientée donnée S:
où endA est l'élément vectoriel de surface
NOTE 1 – Le courant électrique à travers une surface est égal à la limite du quotient de la charge électrique traversant cette surface pendant un intervalle de temps par la durée de cet intervalle lorsque cette durée tend vers zéro.
NOTE 2 – Pour des porteurs de charge confinés sur une surface, le courant électrique est défini à travers une courbe de cette surface (voir la note au terme "densité linéique de courant").
[IEV number 121-11-13]Тематики
- электротехника, основные понятия
Синонимы
EN
DE
- (elektrische) Stromstärke
- Leitungsstromstärke
- Stromstärke, (elektrische)
FR
Русско-немецкий словарь нормативно-технической терминологии > ток проводимости
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2 длительный допустимый ток
- Strombelastbarkeit, f
- Dauerstrombelastbarkeit, f
(длительный) допустимый ток
Максимальное значение электрического тока, который может протекать длительно по проводнику, устройству или аппарату при определенных условиях без превышения определенного значения их температуры в установившемся режиме
[ ГОСТ Р МЭК 60050-826-2009]
Этот ток обозначают IZ
[ ГОСТ Р 50571. 1-2009 ( МЭК 60364-1: 2005)]EN
(continuous) current-carrying capacity
ampacity (US)
maximum value of electric current which can be carried continuously by a conductor, a device or an apparatus, under specified conditions without its steady-state temperature exceeding a specified value
[IEV number 826-11-13]
ampacity
The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
[National Electrical Cod]FR
courant (permanent) admissible, m
valeur maximale du courant électrique qui peut parcourir en permanence, un conducteur, un dispositif ou un appareil, sans que sa température de régime permanent, dans des conditions données, soit supérieure à la valeur spécifiée
[IEV number 826-11-13]Ampacity, the term is defined as the maximum amount of current a cable can carry before sustaining immediate or progressive deterioration. Also described as current rating or current-carrying capacity, is the RMS electric current which a device can continuously carry while remaining within its temperature rating. The ampacity of a cable depends on:
- its insulation temperature rating;
- conductor electrical properties for current;
- frequency, in the case of alternating currents;
- ability to dissipate heat, which depends on cable geometry and its surroundings;
- ambient temperature.
Electric wires have some resistance, and electric current flowing through them causes voltage drop and power dissipation, which heats the cable. Copper or aluminum can conduct a large amount of current before melting, but long before the conductors melt, their insulation would be damaged by the heat.
The ampacity for a power cable is thus based on physical and electrical properties of the material & construction of the conductor and of its insulation, ambient temperature, and environmental conditions adjacent to the cable. Having a large overall surface area may dissipate heat well if the environment can absorb the heat.
In a long run of cable, different conditions govern, and installation regulations normally specify that the most severe condition along the run governs the cable's rating. Cables run in wet or oily locations may carry a lower temperature rating than in a dry installation. Derating is necessary for multiple circuits in close proximity. When multiple cables are near, each contributes heat to the others and diminishes the amount of cooling air that can flow past the individual cables. The overall ampacity of the insulated conductors in a bundle of more than 3 must be derated, whether in a raceway or cable. Usually the de-rating factor is tabulated in a nation's wiring regulations.
Depending on the type of insulating material, common maximum allowable temperatures at the surface of the conductor are 60, 75 and 90 degrees Celsius, often with an ambient air temperature of 30°C. In the U.S., 105°C is allowed with ambient of 40°C, for larger power cables, especially those operating at more than 2 kV. Likewise, specific insulations are rated 150, 200 or 250°C.
The allowed current in cables generally needs to be decreased (derated) when the cable is covered with fireproofing material.
For example, the United States National Electric Code, Table 310-16, specifies that up to three 8 AWG copper wires having a common insulating material (THWN) in a raceway, cable, or direct burial has an ampacity of 50 A when the ambient air is 30°C, the conductor surface temperature allowed to be 75°C. A single insulated conductor in air has 70 A rating.
Ampacity rating is normally for continuous current, and short periods of overcurrent occur without harm in most cabling systems. The acceptable magnitude and duration of overcurrent is a more complex topic than ampacity.
When designing an electrical system, one will normally need to know the current rating for the following:- Wires
- Printed Circuit Board traces, where included
- Fuses
- Circuit breakers
- All or nearly all components used
Some devices are limited by power rating, and when this power rating occurs below their current limit, it is not necessary to know the current limit to design a system. A common example of this is lightbulb holders.
[http://en.wikipedia.org/wiki/Ampacity]
Тематики
- электротехника, основные понятия
Синонимы
EN
DE
- Dauerstrombelastbarkeit, f
- Strombelastbarkeit, f
FR
- courant admissible, m
- courant permanent admissible, m
Русско-немецкий словарь нормативно-технической терминологии > длительный допустимый ток
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3 ток
ток
Скалярная величина, равная сумме электрического тока проводимости, электрического тока переноса и электрического тока смещения сквозь рассматриваемую поверхность.
[ ГОСТ Р 52002-2003]EN
total electric current
scalar quantity given by the flux of the total current density Jt through a given directed surface S:
where endA is the vector surface element
NOTE – The total electric current It is given by
It = I + ID
where I is the electric current and ID the displacement current.
[IEV number 121-11-45]FR
courant électrique total, m
grandeur scalaire égale au flux de la densité de courant total Jt à travers une surface orientée donnée S:
où endA est l'élément vectoriel de surface
NOTE – Le courant électrique total It est donné par
It = I + ID
où I est le courant électrique et ID le courant de déplacement.
[IEV number 121-11-45]Тематики
- электротехника, основные понятия
Действия
- включать ток
- длительно пропускать ток
- коммутировать ток
- ограничивать ток
- отключать ток
- потреблять ток
- проводить ток
- пропускать ток
Синонимы
EN
DE
FR
Русско-немецкий словарь нормативно-технической терминологии > ток
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4 ток смещения
ток смещения
Совокупность электрического тока смещения в пустоте и электрического тока поляризации, количественно характеризуемая скалярной величиной, равной производной по времени от потока электрического смещения сквозь рассматриваемую поверхность.
[ ГОСТ Р 52002-2003]EN
displacement current
scalar quantity equal to the flux of the displacement current density JD through a given directed surface S:
where endA is the vector surface element
[IEV number 121-11-43]FR
courant de déplacement, m
grandeur scalaire égale au flux de la densité de courant de déplacement JD à travers une surface orientée donnée S:
où endA est l'élément vectoriel de surface
[IEV number 121-11-43]Тематики
- электротехника, основные понятия
Синонимы
EN
DE
FR
Русско-немецкий словарь нормативно-технической терминологии > ток смещения
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5 электрический ожог
электрический ожог
Ожог кожи или органов вследствие протекания тока по их поверхности или через них.
[ ГОСТ Р МЭК 60050-195-2005]EN
electric burn
burning of the skin or an organ caused by an electric current along its surface or through it
Source: 604-04-18 MOD
[IEV number 195-03-01]FR
brûlure électrique
brûlure de la peau ou d'un organe, causée par le passage superficiel ou en profondeur d'un courant électrique
Source: 604-04-18 MOD
[IEV number 195-03-01]Тематики
EN
DE
FR
Русско-немецкий словарь нормативно-технической терминологии > электрический ожог
См. также в других словарях:
surface current — paviršinė srovė statusas T sritis fizika atitikmenys: angl. surface current vok. Oberflächenstrom, m rus. поверхностный ток, m pranc. courant de surface, m; courant superficiel, m … Fizikos terminų žodynas
surface current density — paviršinės srovės tankis statusas T sritis fizika atitikmenys: angl. surface current density; surface density of current vok. Flächenstromdichte, f; Oberflächenstromdichte, f rus. плотность поверхностного тока, f; поверхностная плотность тока, f… … Fizikos terminų žodynas
surface density of current — paviršinės srovės tankis statusas T sritis fizika atitikmenys: angl. surface current density; surface density of current vok. Flächenstromdichte, f; Oberflächenstromdichte, f rus. плотность поверхностного тока, f; поверхностная плотность тока, f… … Fizikos terminų žodynas
Surface weather observation — Surface weather observations are the fundamental data used for safety as well as climatological reasons to forecast weather and issue warnings worldwide. [Office of the Federal Coordinator of Meteorology. [http://www.ofcm.gov/fmh 1/pdf/B CH2.pdf… … Wikipedia
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Surface of Eceon — (or Surface of Eceyon), is a supergroup of sorts whose music has been described as ambient, space rock. This unit, which has a penchant for the phantasmagoric, includes members of from Landing and Yume Bitsu, two notable psychedelic rock groups.… … Wikipedia
