The cabinet enclosure is made of bent aluminium sheet, which is previously degreased, phosphated and powder-painted in any colour or of plastic (fibreglass reinforced thermosetting polyester). Cabinets made of aluminium sheet have a double roof to prevent condensation of water vapour. The structure is mounted on a concrete foundation (views and dimensions of prefabricated concrete foundations were presented in the “Cable connection boxes in aluminium enclosures” chapter in section 5.2). A lightweight enclosure of aluminium sheet facilitates transportation and placement. Manufacturing technology and advantages of plastic cabinets are described in the “Cabling, metering and cabling & metering connection boxes constructed with plastic enclosures” chapter.