Enclosure with door for the assembly of distribution boards up to 250 A intended to be operated by ordinary persons according to IEC 61439-3. Open enclosure walls for the assembly or as single enclosure with closing plates. All insulated and made of high-quality polycarbonate. Quick enclosure connection with connectors and integrated gaskets. Large wall openings for the wiring. Cable entry via flanges. Wall fastening directly on enclosure, via external brackets or with mounting profile rails. Circuit breaker box with 54 modules for the installation of DIN rail equipment according to DIN 43880. With PE and N terminals for copper conductors. N separable for different potentials. With blanking strips for unused DIN rail openings and labelling strips for circuit identification. Transparent door and sealable door lockings with tool operation. With closing plates set.