Main Switch (Isolator): Positioned at the top of the distribution board diagram, it provides “double pole” isolation, simultaneously breaking live and neutral conductors for safe maintenance. A distribution board or distribution box is where the main power supply is distributed to multiple loads. And all the switching and protective devices are installed in the distribution box. Inside, you'll find parts like circuit breakers and fuses that protect the system from problems like overloads and short circuits. It is a vital part and central hub of any electrical system. The hub distributes electrical power from a single input source to various circuits throughout a building.