frequency code

signal ['sɪgnəl] ( British pt & pp signalled, cont signalling, American pt & pp signaled, cont signaling)

1 noun

(a) (indication) signal m;

∎ to give sb the signal to do sth donner à qn le signal de faire qch;

∎ he'll give the signal to attack il donnera le signal de l'attaque;

∎ she gave the signal for us to leave elle nous a donné le signal de départ;

∎ you're sending all the wrong signals if you want her to realize you're attracted to her si tu veux qu'elle comprenne que tu es attiré par elle, il faut que ton attitude le montre;

∎ he's putting out a lot of confusing signals son attitude n'est pas claire;

∎ it was the first signal (that) the regime was weakening c'était le premier signe de l'affaiblissement du régime;

∎ the demonstration is a clear signal to the government to change its policy la manifestation signifie clairement que le gouvernement doit changer de politique;

∎ to send smoke signals envoyer des signaux de fumée

(b) Railways sémaphore m

(c) Radio, Telecommunications & Television signal m;

∎ radio signal signal m radio;

∎ Radio station signal indicatif m (de l'émetteur)

2 compound-forming noun

Radio & Telecommunications (strength, frequency) de signal

3 adjective

formal insigne;

∎ you showed a signal lack of tact vous avez fait preuve d'une maladresse insigne

4 transitive verb

(a) (send signal to) envoyer un signal à;

∎ to signal sb faire signe à qn;

∎ he signalled the plane forward il a fait signe au pilote d'avancer;

∎ the brain signals the muscles to contract le cerveau envoie aux muscles le signal de se contracter

(b) (indicate → refusal) indiquer, signaler; (→ malfunction) signaler, avertir de;

∎ the parachutist signalled his readiness to jump le parachutiste fit signe qu'il était prêt à sauter;

∎ the linesman signalled the ball out le juge de ligne a signalé que le ballon était sorti;

∎ the cyclist signalled a left turn le cycliste a indiqué qu'il tournait à gauche

(c) (announce, mark → beginning, end, change) marquer;

∎ the speech signalled a radical change in policy le discours a marqué une réorientation politique radicale;

∎ this signals the start of the rainy season cela indique le début ou c'est le signe du début de la saison des pluies;

∎ her resignation signalled the beginning of the end sa démission a marqué le début de la fin

5 intransitive verb

(a) (gesture) faire des signes;

∎ to signal to sb to do sth faire signe à qn de faire qch;

∎ he signalled for the bill il a fait signe qu'il voulait l'addition;

∎ she was signalling for us to stop elle nous faisait signe de nous arrêter

(b) (send signal) envoyer un signal;

∎ the satellite is still signalling le satellite émet ou envoie toujours des signaux

(c) Cars (with indicator) mettre son clignotant; (with arm) indiquer de la main un changement de direction

►► Aviation & Nautical signal beacon balise f;

Nautical signal book code m international des signaux;

Railways signal box poste m de signalisation;

signal communications télécommunications fpl, transmissions fpl;

signal flag Military fanion m de signalisation; Nautical pavillon m pour signaux;

signal flare (rocket) fusée f éclairante; (stationary) feu m de Bengale;

signal lamp (for making signals) lampe f ou projecteur m de signalisation; (serving as a signal) (lampe f) témoin m;

signal light Nautical fanal m; Military voyant m (lumineux);

British Military signals officer officier m des transmissions;

American signal red vermillon m chinois;

signal rocket fusée f de signalisation;

American signal tower poste m d'aiguillage

 

(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 I_Z
[ 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

• длительно допустимый ток
• допустимый ток

EN

• ampacity (US)
• continuous current
• continuous current-carrying capacity
• current-carrying capacity

DE

• Dauerstrombelastbarkeit, f
• Strombelastbarkeit, f

FR

• courant admissible, m
• courant permanent admissible, m