The low-voltage bars are made up of reinforced metal cabins with front compartments where the switches, meters, and control and protective mechanisms are located. The bars are positioned in the rear section along with the voltage and current transformers, the power bars and the connections for the cables running to the exterior. The switches can be removed and the current is adapted to the equipment they supply.
The low-voltage bars supply the Motor Control Centres (MMC), the battery-charging equipment, and the motors with power ratings between 75 kW and 199 kW.
The motor monitoring centres consist of separate cubicles. These can be removed and are grouped together in accordance with the status of the various motors. They are used to power motors and services with a power rating below 75 kW and a power supply below 150 A.
Two power and lighting units have been fitted to supply power for general services such as lighting, sockets, cabin heating resistors and other services. These are supplied by three transformers of 500, 500 and 120 kVA with a transformer ratio of 400/400-230 V.
Two sets of 110 V batteries complete with chargers and a current distribution panel have been fitted to power the switch control unit, signals, protective devices, the emergency equipment motors, etc. One of the 24 V batteries supplies a direct current.
For services requiring an uninterrupted AC power supply, two 25 kVA (approximately) battery-powered inverters have been fitted. These guarantee AC power supply in the event of a power failure.
The plant also has two 800-kW diesel-powered backup generators. In the event of a general power failure lasting over an hour, the generators can be used to power essential equipment at the plant.