Glosario Inglés Términos Eléctricos

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LINES AND CABLES
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LINES AND CABLES |

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AIR LINES
The air lines are in use for transmission of big powers and for electrical supply to rural zones or of population disperses.
Classification (according to RD 223/2008)
- Special category: Un> 220 kV and them of belonging to the network of transport of low tension
- 1 ª category: 220>Un> 66kV
- 2 ª category: 30 kV<Un <66 kV
- 3 ª category: 1 kV <Un <30 kV
ELECTRICAL DRIVER
An electrical driver is a material that offers few resistance to the step of the electricity. Generally they are alloys or compounds with free electrons that allow the movement of loads.
Materials:
- Copper, aluminium, steel.
- Alloys (bronze, Almelec, Aldrey).
- Compounds (Aluminium - steel, Copperweld, Alumoweld,Almelec-steel).

Habitually: Drivers of aluminium plaited (flexibility) with soul of steel

Types of drivers:
- Phase drivers
- Drivers of neutral (in B.T.)
- Guard's threads or cables of land (of galvanized steel)

Regulation: RLAT, UNE 21-018-80, CEI,…

Drivers' grouping (2, 3 or 4):
- L
- U effect crowns
- I (more refrigeration)

CABLES OF LAND
Are cables of steel (oneor two) connected electrically to land of trustworthy way, with object to protect to drivers of the action of atmospheric beams direct.
They are used in the majority of the lines of 1 ª category
IRON WORKS
Are elements used in the air lines for the fixation of the insulators to the post and to the driver, the fixings of cables of land, the elements of electrical protection of insulators andthe accessories of the drivers since they are dividers, vibrators, etc.
Materials:
- Iron and steel galvanized (UNE 21-009-80),
- Alloys of aluminum (UNE 38-252).
INSULATORS
Element or insulating elements that are placed between driver and the structure supports.
Materials: porcelain, moderate glass, silicone composite.
Types of insulators
- Rigid: subjects without freedom. An aloneelement.
- Suspended: formed by chains from 1 to 30 elements
· 14 insulators in 220 kV
· 20 insulators in 400 KV

The tension distribution is not equal in all the elements.
The electrical equivalent of an insulator is one condenser of capacity C, but a chain of n insulators it is not equivalent to n condensers in series.

Coordination of isolation
- Known the levels of overvoltageof a system, they are fixed the basic levels of isolation (BIL) according to the regulation.
- With the fixed tension levels, the distances are established minimal driver - structure and driver - driver who is necessary to avoid unloads.
- These distance they form the design of the support and the length of chain of insulators.
Mechanical characteristics:
- Dimensions and resistance to thebreak.
- Mechanical load of 24 hours.
- Electromechanical load of short duration.
- Resistance to the sudden change of T ª of the insulator.

Electrical characteristics:
- Tension of perforation to industrial frequency.
- Tension of turning in dry and under rain.
- Tension supported to industrial frequency in I dry and rain.
- Tension of turning 50 % on shock wave type I border ofPositive and negative polarity.
SUPPORT
Supports of suspension and tie – alignment: they support weight of the drivers and insulators.
Supports of anchorage: which the drivers keep tense, and they provide with firm points to the line. They are in the habit of arranging every 3 Km.
Angle supports: the drivers support in the vertexes of the angles that form two alignments, also have that tosupport the tension of the driver.
Terminal Supports - of beginning or end of line: of end of line, which they are of stronger construction, so they must resist all the efforts of the drivers.
CABLE ISOLATED (RD 223/2008)
Set constituted for one o more isolated drivers and his coatings.
The transport of electric power of 220 kV and 400 kV it effects underground in urban zones or for reasons...