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. This document provides specifications for various distribution boxes including dimensions, mounting sizes, and number of ways. As a core component of electrical distribution systems, the selection of the installation height for distribution boxes is critical, as it must balance functionality. trial applications. Check out this quick guide: Think about how many devices you need, where you will install the box, and the environment. In 63 / 100 / 160 / 315 KVA distribution box, the cross se the Isolator with cross section as mentioned above throughout the length.