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1 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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2 максимальная температура поверхности взрывозащищенного электрооборудования (электротехнического устройства)
максимальная температура поверхности взрывозащищенного электрооборудования (электротехнического устройства)
Наибольшая температура, до которой могут нагреваться в наихудших условиях работы любые части или поверхности электротехнического устройства, представляющие при нагреве опасность в отношении воспламенения окружающей взрывоопасной среды.
Примечание
Наихудшие условия работы включают перегрузки и аварийные условия, которые признаны стандартами на конкретное электрооборудование и на отдельные виды взрывозащиты.
[ ГОСТ 12.2.020-76]Тематики
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3. Максимальная температура поверхности взрывозащищенного электрооборудования (электротехнического устройства)
D. Maximale Oberflächentemperatur
E. Maximum Surface Temperature
F. Temperature maximale de sueface
Наибольшая температура, до которой могут нагреваться в наихудших условиях работы любые части или поверхности электротехнического устройства, представляющие при нагреве опасность в отношении воспламенения окружающей взрывоопасной среды.
Примечание. Наихудшие условия работы включают перегрузки и аварийные условия, которые признаны стандартами на конкретное электрооборудование и на отдельные виды взрывозащиты.
Источник: ГОСТ 12.2.020-76: Система стандартов безопасности труда. Электрооборудование взрывозащищенное. Термины и определения. Классификация. Маркировка оригинал документа
Русско-немецкий словарь нормативно-технической терминологии > максимальная температура поверхности взрывозащищенного электрооборудования (электротехнического устройства)
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3 температура доступной поверхности
температура доступной поверхности
Температура любой поверхности, до которой во время нормальной работы можно дотронуться пальцем или рукой, в том числе во время наполнения водой увлажнителя и слива воды из него.
[ ГОСТ Р 52423-2005]Тематики
- ингаляц. анестезия, искусств. вентиляц. легких
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Русско-немецкий словарь нормативно-технической терминологии > температура доступной поверхности
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4 глобальное потепление
глобальное потепление
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[ http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]EN
global warming
Changes in the surface-air temperature, referred to as the global temperature, brought about by the greenhouse effect which is induced by emission of greenhouse gases into the air. (Source: WRIGHT)
[http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]Тематики
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Русско-немецкий словарь нормативно-технической терминологии > глобальное потепление
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5 климат
климат
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[ http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]EN
climate
The average weather condition in a region of the world. Many aspects of the Earth's geography affect the climate. Equatorial, or low, latitudes are hotter than the polar latitudes because of the angle at which the rays of sunlight arrive at the Earth's surface. The difference in temperature at the equator and at the poles has an influence on the global circulation of huge masses of air. Cool air at the poles sinks and spreads along the surface of the Earth towards the equator. Cool air forces its way under the lower density warmer air in the lower regions, pushing the lighter air up and toward the poles, where it will cool and descend. (Source: WRIGHT)
[http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]Тематики
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Русско-немецкий словарь нормативно-технической терминологии > климат
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6 геологический процесс
геологический процесс
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[ http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]EN
geological process
Dynamic actions or events that occur at the Earth's surface due to application of natural forces resulting from gravity, temperature changes, freezing and thawing, chemical reactions, seismic shaking, and the agencies of wind and moving water, ice and snow. Where and when a force exceeds the strength of the earth material, the material is changed by deformation, translocation, or chemical reactions. (Source: DUNSTE)
[http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]Тематики
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Русско-немецкий словарь нормативно-технической терминологии > геологический процесс
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7 рост водорослей
рост водорослей
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[ http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]EN
algal bloom
Excessive and rapid growth of algae and other aquatic plants when they are stimulated to grow too quickly by pollution. It takes place when there are too many nutrients in the water and is aggravated when accompanied by a rise in temperature. Although the algae grow quickly they soon die because they have swallowed up all the water's nutrients. As they decompose they tend to rise to the surface and form a green slime. Algal bloom have increased because higher levels of nitrogen and phosphates from agricultural areas have leached from the fields into water courses. (Source: WRIGHT)
[http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]Тематики
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Русско-немецкий словарь нормативно-технической терминологии > рост водорослей
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8 циркуляция водных слоев
циркуляция водных слоев
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[ http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]EN
overturn (limnology)
The circulation, especially in the fall and spring, of the layers of water in a lake or sea, whereby surface water sinks and mixes with bottom water; it is caused by changes in density differences due to changes in temperature, and is especially common wherever lakes are icebound in winter. (Source: BJGEO)
[http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]Тематики
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Русско-немецкий словарь нормативно-технической терминологии > циркуляция водных слоев
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9 циркуляция морской воды
циркуляция морской воды
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[ http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]EN
sea circulation
Large-scale horizontal water motion within an ocean. The way energy from the sun, stored in the sea, is transported around the world. The currents explain, for example, why the UK has ice-free ports in winter, while St. Petersburg, at the same latitude as the Shetland Islands, needs ice breakers. Evidence is growing that the world's ocean circulation was very different during the last ice age and has changed several times in the distant past, with dramatic effects on climate. The oceans are vital as storehouses, as they absorb more than half the sun's heat reaching the earth. This heat, which is primarily absorbed near the equator is carried around the world and released elsewhere, creating currents which last up to 1.000 years. As the Earth rotates and the wind acts upon the surface, currents carry warm tropical water to the cooler parts of the world. The strength and direction of the currents are affected by landmasses, bottlenecks through narrow straits, and even the shape of the sea-bed. When the warm water reaches polar regions its heat evaporates into the atmosphere, reducing its temperature and increasing its density. When sea-water freezes it leaves salt behind in the unfrozen water and this cold water sinks into the ocean and begins to flow back to the tropics. Eventually it is heated and begins the cycle all over again. (Source: MGH / WRIGHT)
[http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]Тематики
EN
DE
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Русско-немецкий словарь нормативно-технической терминологии > циркуляция морской воды
См. также в других словарях:
surface temperature — paviršiaus temperatūra statusas T sritis fizika atitikmenys: angl. skin temperature; surface temperature vok. Hauttemperatur, f; Oberflächentemperatur, f rus. поверхностная температура, f; температура поверхности, f pranc. température de surface … Fizikos terminų žodynas
Sea surface temperature — Weekly average sea surface temperature for the World Ocean during the first week of February 2011, during a period of La Niña … Wikipedia
Global Mean Surface Temperature — Die Global Mean Surface Temperature (GMST), übersetzt „Globale Durchschnittstemperatur an der Oberfläche“, bezeichnet einen aus gemittelten Messwerten errechneten Durchschnittswert für die Temperaturverteilung auf der Erdoberfläche. Die GMST… … Deutsch Wikipedia
Berkeley Earth Surface Temperature — Das Berkeley Earth Surface Temperature Projekt (»BEST«) ist ein Projekt der University of California, Berkeley, das sich nach massiver öffentlicher Kritik an bestehenden Projekten zur Quantifizierung der globalen Erwärmung zum Ziel gesetzt hatte … Deutsch Wikipedia
Surface-mount technology — (SMT) is a method for constructing electronic circuits in which the components (SMC, or Surface Mounted Components) are mounted directly onto the surface of printed circuit boards (PCBs). Electronic devices so made are called surface mount… … Wikipedia
Temperature record — For extreme records instead of records as a set of data, see Temperature extremes For instrument derived temperature records, see Instrumental temperature record … Wikipedia
Temperature — This article is about the thermodynamic property. For other uses, see Temperature (disambiguation). A map of global long term monthly average surface air temperatures i … Wikipedia
Temperature record of the past 1000 years — The temperature record of the past 1,000 years describes the reconstruction of temperature for the last 1000 years on the Northern Hemisphere. A reconstruction is needed because a reliable surface temperature record exists only since about 1850.… … Wikipedia
temperature — noun 1 how hot or cold sth is ADJECTIVE ▪ high, hot, warm ▪ Yesterday the town reached its highest ever February temperature. ▪ cold, cool, low … Collocations dictionary
température de surface — paviršiaus temperatūra statusas T sritis fizika atitikmenys: angl. skin temperature; surface temperature vok. Hauttemperatur, f; Oberflächentemperatur, f rus. поверхностная температура, f; температура поверхности, f pranc. température de surface … Fizikos terminų žodynas
Temperature record since 1880 — The website [ [http://www.ncdc.noaa.gov/oa/climate/research/anomalies/anomalies.html NCDC: Global Surface Temperature Anomalies ] ] of the National Oceanic and Atmospheric Administration contains detailed data of the annual land and ocean… … Wikipedia
