-
1 допустимый длительный ток кабеля (провода)
допустимый длительный ток кабеля (провода)
-
[Интент]
допустимый длительный ток (проводника)
Максимальный электрический ток, который проводник способен проводить в продолжительном режиме без превышения его установившейся температурой определённого значения.
Допустимый длительный ток является одной из основных характеристик проводника. Он представляет собой максимальный электрический ток, который проводник может проводить длительно (неделями, месяцами, годами) не перегреваясь. Значение допустимого длительного тока зависит от сечения проводника, материалов из которых выполнены проводник и его изоляция, способов монтажа проводника в электроустановке здания. Допустимый длительный ток проводника фактически является его номинальным током. В электроустановках зданий выполняют защиту проводников от сверхтоков, протекание которых по проводникам сопровождается их перегревом.
[ http://www.volt-m.ru/glossary/letter/%C4/view/11/]EN
current carrying capacity
maximum current a cable circuit (one or several conductors) can support resulting in a specified increase of the surface temperature of the conductor beyond the ambient temperature, not exceeding the maximum allowed operating temperature of the cable
[IEC 61156-1, ed. 3.0 (2007-06< size="2">)]FR
courant maximal admissible
courant maximal qu’un circuit de câble (un ou plusieurs conducteurs) peut supporter avec une augmentation spécifiée de la température de surface du conducteur au delà de la température ambiante, et ne dépassant pas la température maximale de fonctionnement autorisée du câble
[IEC 61156-1, ed. 3.0 (2007-06< size="2">)]Номинальный ток устройств защиты от короткого замыкания может превышать допустимый длительный ток кабеля.
[ ГОСТ Р 50571. 5-94 ( МЭК 364-4-43-77)]Допустимые длительные токи для проводов и кабелей, проложенных в коробах, а также в лотках пучками, должны приниматься...
[ПУЭ]Тематики
- кабели, провода...
- электроустановки
EN
- ampere capacity
- current carrying capacity
- current carrying capacity of the cable
- current carrying capacity of the conductors
- current-carrying capacity of the cable
FR
Русско-французский словарь нормативно-технической терминологии > допустимый длительный ток кабеля (провода)
-
2 длительный допустимый ток
- courant permanent admissible, m
- courant admissible, m
(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-французский словарь нормативно-технической терминологии > длительный допустимый ток
См. также в других словарях:
Power cable — This article is about electric power conductors. For portable equipment, see power cord. A power cable is an assembly of two or more electrical conductors, usually held together with an overall sheath. The assembly is used for transmission of… … Wikipedia
Cable television in the United States — is a common form of television delivery, generally by subscription. Cable television first became available in the United States in 1948, with subscription services in 1949. Data by SNL Kagan shows that as of 2006 about 58.4% of all American… … Wikipedia
Submarine power cable — Submarine power cables are cables for electrical power running through the sea, below the surface.A DC system may use the ground and seawater as a return path for current. However, this cannot be always practiced because of disturbances to… … Wikipedia
Copper wire and cable — Copper has been used in electric wiring since the invention of the electromagnet and the telegraph in the 1820s.[1][2] The invention of the telephone in 1876 proved to be another early boon for copper wire.[3] Today, despite competition from… … Wikipedia
The Price Is Right (U.S. game show) — The Price Is Right Format Game show Created by Mark Goodson Bill Todman Directed b … Wikipedia
High-voltage direct current — HVDC or high voltage, direct current electric power transmission systems contrast with the more common alternating current systems as a means for the bulk transmission of electrical power. The modern form of HVDC transmission uses technology… … Wikipedia
Submarine communications cable — A cross section of a submarine communications cable. 1 Polyethylene 2 Mylar tape 3 Stranded steel wires 4 Aluminium water barrier 5 Polycarbonate 6 Copper or aluminium tube 7 Petroleum jelly 8 Optical fib … Wikipedia
допустимый длительный ток кабеля (провода) — [Интент] допустимый длительный ток (проводника) Максимальный электрический ток, который проводник способен проводить в продолжительном режиме без превышения его установившейся температурой определённого значения. Допустимый длительный ток… … Справочник технического переводчика
National broadband plans from around the world — Broadband is a term normally considered to be synonymous with a high speed connection to the internet. The term itself is technology neutral; broadband can be delived by a range of technologies including DSL, LTE or next generation access. This… … Wikipedia
Coaxial cable — RG 59 flexible coaxial cable composed of: A: outer plastic sheath B: woven copper shield C: inner dielectric insulator D: copper core Coaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by … Wikipedia
Shielded cable — A shielded cable is an electrical cable of one or more insulated conductors enclosed by a common conductive layer. The shield may be composed of braided strands of copper (or other metal), a non braided spiral winding of copper tape, or a layer… … Wikipedia
