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1 загрязнение (в электробезопасности)
загрязнение
Присутствие инородного вещества: твердого, жидкого или газообразного (ионизированные газы), - которое может вызвать уменьшение диэлектрической прочности или поверхностного сопротивления.
[ ГОСТ Р 52319-2005( МЭК 61010-1: 2001)]
загрязнение
Любое добавление инородных веществ, твердых, жидких или газообразных (ионизированных газов), которые могли бы уменьшить электрическую прочность изоляции или удельное сопротивление поверхности.
[ ГОСТ Р 50030. 1-2000 ( МЭК 60947-1-99)]EN
pollution
any condition of foreign matter, solid, liquid or gaseous (ionized gases), that may affect dielectric strength or surface resistivity
[IEC 60947-1, ed. 5.0 (2007-06)]
pollution
any addition of foreign matter, solid, liquid or gaseous that can produce a permanent reduction of dielectric strength or surface resistivity of the insulation
NOTE – Ionized gases of a temporary nature are not considered as to be a pollution.
[IEV number 442-01-28]
contamination
the first is defined as area and the second as particulate. The first is caused by surface contaminants that cannot be removed by cleaning or are stained after cleaning. Those may be foreign matter on the surface of, for example a localized area that is smudged, stained, discoloured, mottled, etc., or large areas exhibiting a hazy or cloudy appearance resulting from a film of foreign materials
[IEC 62276, ed. 1.0 (2005-05)]FR
pollution
tout apport de matériau étranger solide, liquide ou gazeux (gaz ionisés) qui peut entraîner une réduction de la rigidité diélectrique ou de la résistivité de la surface
[IEC 60947-1, ed. 5.0 (2007-06)]
pollution
tout apport de matériau étranger solide, liquide ou gazeux qui peut entraîner une réduction permanente de la rigidité diélectrique ou de la résistivité de surface de l'isolation
NOTE – Les gaz ionisés de nature fugace ne sont pas considérés comme une pollution.
[IEV number 442-01-28]
Тематики
Обобщающие термины
EN
DE
FR
Русско-немецкий словарь нормативно-технической терминологии > загрязнение (в электробезопасности)
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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 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
EN
DE
FR
Русско-немецкий словарь нормативно-технической терминологии > климат
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