This switch is usually located near the top of the box and has two positions – off and on. And all the switching and protective devices are installed in the distribution box. Single Phase Distribution Box generally consists of Double Pole MCBs, Single Pole MCBs, and RCCBs. Before you can turn on a main breaker box, you must make sure you have the appropriate safety measures in place. Electric explains how to safely understand and navigate your breaker panel. Identify main breaker and individual circuit breakers. You'll learn how to connect the main switch, MCBs, neutral link, and earth bar, plus essential tips to.