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21 щит промежуточного распределения электроэнергии
- subdistribution low-voltage switchboard
- sub-distribution switchboard
- secondary distribution switchgear
- secondary distribution switchboard
щит промежуточного распределения электроэнергии
НКУ промежуточного распределения электроэнергии
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[Интент]
Рис. ABBПараллельные тексты EN-RU
These assemblies are usually provided with one incoming unit and many outgoing units.
The apparatus housed inside the assembly are mainly molded-case circuit-breakers and/or miniature circuitbreakers.
The rated currents and the short-circuit currents of secondary distribution switchgear are lower than those of primary distribution switchgear.
The constructional models provide for the use of metal or insulating material enclosures and can be both floor- or wall-mounted, according to dimensions and weight.
In case the assemblies are used by unskilled persons, the Standard IEC 60439-3 is to be applied.
The distribution boards (ASD) are subject to the additional prescriptions of the Standard IEC 60439-3.
[ABB]Данные НКУ обычно имеют один вводной и много выводных блоков.
Внутри такого НКУ смонтированы в основном автоматические выключатели в литом корпусе и/или модульные автоматические выключатели.
Номинальные токи и токи короткого замыкания НКУ промежуточного распределения меньше чем у комплектных устройств первичного распределения электроэнергии.
Данные НКУ изготавливают в металлической или пластмассовой оболочке для установки на полу или на стене в зависимости от их размера и массы.
Если НКУ промежуточного распределения электроэнергии предназначены для установки в местах доступных неквалифицированному персоналу, то они должны соответствовать требованиям стандарта МЭК 60439-3.
[Перевод Интент]Тематики
- НКУ (шкафы, пульты,...)
Синонимы
EN
Русско-английский словарь нормативно-технической терминологии > щит промежуточного распределения электроэнергии
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22 поддерживать работу
•In many cases the voltage required to keep the motor running is significantly lower than that required to start the motor.
•The power necessary to maintain a charge-coupled memory device...
Русско-английский научно-технический словарь переводчика > поддерживать работу
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23 понижать
. снижать•This will heat the thermistor enough to lower (or decrease, or reduce, or diminish, or cut) the resistance to 200 ohms.
•The transformer is suitable for stepping down (or reducing, or decreasing) the supply voltage to 85 volts on open circuit.
Русско-английский научно-технический словарь переводчика > понижать
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24 минимальное напряжение перекрытия
Engineering: lower limiting flashover voltageУниверсальный русско-английский словарь > минимальное напряжение перекрытия
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25 нижний предел напряжения перекрытия
Electrical engineering: lower limiting flashover voltageУниверсальный русско-английский словарь > нижний предел напряжения перекрытия
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26 понижать
depress, decrease, reduce, relieve* * *понижа́ть гл.
bring down, lowerпонижа́ть напряже́ние — step down a voltageпонижа́ть поря́док ма́трицы — deflate a matrixпонижа́ть поря́док систе́мы уравне́ний — reduce the order of a set [system] of equationsпонижа́ть сте́пень уравне́ния — depress an equationпонижа́ть число́ оборо́тов — gear down* * * -
27 выходное напряжение низкого уровня
Русско-английский большой базовый словарь > выходное напряжение низкого уровня
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28 понижать
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29 состояние с низким уровнем
1. low state2. low-voltage stateРусско-английский большой базовый словарь > состояние с низким уровнем
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30 длительный допустимый ток
(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-английский словарь нормативно-технической терминологии > длительный допустимый ток
- 1
- 2
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