26 mm 2 (10 AWG) ground wire must be used, and in all other markets a 6 mm 2 must be used. Power from factory ground must be installed by a qualified electrician. If it's done poorly, you risk short circuits, fire hazards, or system failure. Done right, it ensures. Today, we're diving deep into the world of distribution box grounding, breaking down the standards, and shining a light on those sneaky mistakes that even experienced electricians sometimes make. In factories, construction sites, and even commercial buildings, this question pops up all the time. Single Phase Distribution Box generally consists of Double Pole MCBs, Single Pole MCBs, and RCCBs.