Wall-mounted boxes should be 4. This height makes it easy to reach without bending or stretching. Ground-mounted boxes should be raised 2 to 4 inches to avoid. Electrical enclosure sizes are not universal, but most manufacturers follow common size families. There is no single global chart for standard. In this guide, we'll break down everything you need to know to install a distribution box correctly and confidently. Check for proper IP/NEMA ratings and material quality. Before talking numbers. Pre-fabricated metallic boxes and assemblies Metallic outlet boxes, device boxes, rings and covers Non-metallic outlet boxes, device boxes, rings and covers While-in-use and weatherproof outlet boxes and covers. Junction boxes and pull boxes Related sections: 01 81 16Facility Environmental. REV.