Electrical power cable for forming a direct-current power grid of a building

The building has an electrical network of direct current voltage that is lower than voltage of an electrical network of alternating current for providing electrical supply to a specific equipment e.g. washing machine. A metal driver is provided with a specific conductivity, and has a section that is lower or equal to 1.5 square mm. The metal driver has rupture stress that is higher than 390 Newton. A current of specific intensity and a specific resistivity is passed through the driver.