This document provides specifications for various distribution boxes including dimensions, mounting sizes, and number of ways. Wiring diagram shows both PNP and NPN wiring. Dimensions are shown in mm (in. 81 ft)]. ket of low voltage electric insulating switchboards and industrial boxes. No matter how ha sh the environment is, there is always a proper enclosure for your needs. Available in 4-39 ways, single/double/triple layers, ideal for industrial, commercial, and photovoltaic applications. Check out this quick guide: Think about how many devices you need, where you will install the box, and the environment. Picking the right size helps you stay safe, follow.