1. Electricity Transmission Grid
Set of power lines and stations that form the meshed structure for transferring electricity from the sites where it is produced (power plants) to the sites where it is distributed (users and distribution grids). The national transmission grid is formed by three separate meshed systems which are interconnected, each one having a different voltage (132/150, 220 and 380 kV).
 

2. Overhead lines with pylons for single or double circuit lines
A line is the system that connects two junctions of the grid. It is formed by the power conductors that transfer electricity, by guard wires that protect the conductors against voltage surges having atmospheric origins and by the pylons supporting conductors and guard wires. Lines can be single or double circuit if they are built with one or two groups of conductors, respectively.

3. Electricity station
Plant where the interconnection between lines and energy transformation occurs among the different voltage levels. Through the transformer, two power junctions are connected to different voltages where the corresponding electricity lines converge. The station contains all the equipment necessary for carrying out opening, closing and sectioning the converging lines in order to manage energy flows.

4. Transformer Electricity device that allows connecting and transferring electricity between two grids having a different voltage.

5. Busbars
Metallic structures that materialize the junction where lines having the same voltage converge. A system of bars with a certain voltage is connected through the transformer to another system of bars having a different voltage.

6. Stall of an electricity station
Set of components that connect a line or a transformer to the busbars. It is formed by operating and measuring devices that carry out opening, closing and sectioning of the line as well as measuring the electricity transferred through a line.

7. Switch
Operating device capable of disconnecting, even under heavy loads, the line from the busbars.

8. Service, Protection and Control Panel
Set of devices that control the operations that can be carried out by the equipment in a stall.

9. Overhead - cable transition station
Site where the electricity transits from one overhead line to a cable line.

10. Warning spheres
Spherical objects of different colors and sizes placed on guard wires of the overhead cables warning the presence of an obstacle to aircrafts.