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1 импульсные помехи
импульсные помехи
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[ http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]EN
impulsive noise
Noise characterized by transient short-duration disturbances distributed essentially uniformly over the useful passband of a transmission system. (Source: MGH)
[http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]Тематики
EN
DE
FR
Русско-немецкий словарь нормативно-технической терминологии > импульсные помехи
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2 заземлитель (коммутационный аппарат)
заземлитель
Контактный коммутационный аппарат, используемый для заземления частей цепи, способный выдерживать в течение нормированного времени токи при ненормальных условиях, таких как короткое замыкание, но не предусмотренный для проведения тока при нормальных условиях в цепи.
Примечания
1 Заземлитель может обладать включающей способностью при коротком замыкании.
2 Заземлитель на номинальное напряжение 110 кВ и выше может отключать (коммутировать) и проводить наведенные токи.
[ ГОСТ Р 52726-2007]
выключатель заземления
Механический 1) коммутационный аппарат для заземления частей электрической цепи, способный выдерживать электрические токи заданной продолжительности при ненормальных режимах, например при коротких замыканиях, но не предназначенный для пропускания электрического тока в нормальных режимах работы электрической цепи.
Примечание - Выключатель может быть стойким к токам короткого замыкания.
[ ГОСТ Р МЭК 60050-195-2005]EN
earthing switch
mechanical switching device for earthing parts of an electric circuit, capable of withstanding for a specified duration electric currents under abnormal conditions such as those of short-circuit, but not required to carry electric current under normal conditions of the electric circuit
NOTE – An earthing switch can have a short circuit making capacity.
Source: 441-14-11 MOD, 605-02-43 MOD
[IEV number 195-02-34]FR
connecteur de terre
appareil mécanique de connexion utilisé pour mettre à la terre des parties d'un circuit électrique, capable de supporter, pendant une durée spécifiée, des courants dans des conditions anormales telles que celles de court-circuit, mais non prévu pour transporter le courant électrique dans les conditions normales du circuit électrique
NOTE – Un connecteur de terre peut avoir un pouvoir de fermeture en court circuit.
Source: 441-14-11 MOD, 605-02-43 MOD
[IEV number 195-02-34]1) Должно быть контактный
[Интент]Тематики
- аппарат, изделие, устройство...
- высоковольтный аппарат, оборудование...
- заземление
- электробезопасность
Синонимы
EN
DE
FR
Русско-немецкий словарь нормативно-технической терминологии > заземлитель (коммутационный аппарат)
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3 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
См. также в других словарях:
short duration of imaginal lifespan factor — short duration of imaginal lifespan factor. См. sdi фактор. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) … Молекулярная биология и генетика. Толковый словарь.
short duration of imaginal lifespan factor — short duration of imaginal lifespan factor. = sdi factor (см.). (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) … Молекулярная биология и генетика. Толковый словарь.
short duration light source — impulsinis šviesos šaltinis statusas T sritis fizika atitikmenys: angl. pulse light source; short duration light source vok. impulsartige Lichtquelle, f; Impulslichtquelle, f rus. импульсный источник света, m pranc. source de lumière pulsée, f;… … Fizikos terminų žodynas
of short duration — index provisional Burton s Legal Thesaurus. William C. Burton. 2006 … Law dictionary
short-life — shortˈ life adjective Having a short duration, existence, etc • • • Main Entry: ↑short … Useful english dictionary
short — I. adjective Etymology: Middle English, from Old English sceort; akin to Old High German scurz short, Old Norse skortr lack Date: before 12th century 1. a. having little length b. not tall or high ; low 2. a. not extended in time … New Collegiate Dictionary
short — /ʃɔt / (say shawt) adjective 1. having little length; not long. 2. having little height; not tall; low. 3. extending or reaching only a little way. 4. brief; not extensive: a short speech. 5. concise, as writing. 6. rudely brief; curt; hurting:… …
duration — n. 1) long; moderate; short duration 2) of a certain duration (of short duration) 3) for the duration (of the war) * * * [djʊ(ə) reɪʃ(ə)n] moderate shortduration long of a certain duration (of short duration) for the duration … Combinatory dictionary
duration — /djuˈreɪʃən / (say dyooh rayshuhn) noun 1. continuance in time: *He began to impose suspensions, usually of short duration –frank hardy, 1950. 2. the length of time anything continues: to impose restrictions for the duration of the games. –phrase …
duration — noun (U) formal the length of time that something continues: an illness of relatively short duration | for the duration (of): He was interned and had to stay in the US for the duration of the war … Longman dictionary of contemporary English
short-term — adjective a) of or pertaining to the near or immediate future. This short term plan deals with the next few days. b) of or pertaining to a short duration of time short term exposure Ant: long term … Wiktionary
