-
1 управление землями различного хозяйственного назначения
управление землями различного хозяйственного назначения
—
[ http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]EN
multiple use management area
1) Coordinated management for the most judicious and harmonious use of the land on a long term basis under the concept of combining two or more uses and/or purposes with attention to sustainability and nonimpairment of the natural resources and land area. 2) Use of land for more than one purpose; e.g. grazing of livestock, watershed and wildlife protection, recreation, and timber production. (Source: UNUN / EPAGLO)
[http://www.eionet.europa.eu/gemet/alphabetic?langcode=en]Тематики
EN
DE
FR
Русско-немецкий словарь нормативно-технической терминологии > управление землями различного хозяйственного назначения
-
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
См. также в других словарях:
Multiple use — of the United States national forests means the “harmonious and coordinated management of the various resources, each with the other, without impairment of the productivity of the land, with consideration being given to the relative values of the … Wikipedia
Multiple-use name — A multiple use name is a name used by many different people to protect anonymity.[1] It is a strategy that has been adopted by many unconnected radical and cultural groups, where the construct of personal identity has been criticised.[citation… … Wikipedia
Multiple-Use Sustained-Yield Act of 1960 — Full title Multiple Use Sustained Yield Act of 1960 Acronym MUSYA Effective June 12th, 1960 Citations … Wikipedia
Multiple Use - Sustained Yield Act of 1960 — The Multiple Use Sustained Yield Act of 1960 (or MUSYA) (Public Law 86 527) is a federal law passed by the US Congress on June 12, 1960. This law authorizes and directs the Secretary of Agriculture to develop and administer the renewable… … Wikipedia
Zoar Valley Multiple Use Area — The Zoar Valley Multiple Use Area is a conservation area located at the confuence of the main and south branches of Cattaraugus Creek, on the border of Erie County and Cattaraugus County in western New York, USA. The area is within the Towns of… … Wikipedia
Use case — A use case is a description of a system’s behaviour as it responds to a request that originates from outside of that system.The use case technique is used in software and systems engineering to capture the functional requirements of a system. Use … Wikipedia
Use case diagram — A use case diagram is a type of behavioral diagram defined by the Unified Modeling Language (UML) and created from a Use case analysis. Its purpose is to present a graphical overview of the functionality provided by a system in terms of actors,… … Wikipedia
Multiple representations (mathematics education) — Multiple representations are ways to symbolize, to describe and to refer to the same mathematical entity. They are used to understand, to develop, and to communicate different mathematical features of the same object or operation, as well as… … Wikipedia
Multiple sclerosis — Classification and external resources Demyelination by MS. The CD68 colored tissue shows several macrophages in the area of the lesion. Original scale 1:100 ICD … Wikipedia
Multiple patterning — is a class of technologies developed for photolithography to enhance the feature density. The simplest case of multiple patterning is double patterning, where a conventional lithography process is enhanced to produce double the expected number of … Wikipedia
Multiple inheritance — is a feature of some object oriented computer programming languages in which a class can inherit behaviors and features from more than one superclass. Languages that support multiple inheritance include: C++, Common Lisp (via CLOS), EuLisp (via… … Wikipedia
