For single-phase, use P = V × I. After you know the load, pick a breaker just above your current. Always use the 80% rule for loads that run all the time. 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. Check for proper IP/NEMA ratings and material quality. This video explains the connection of MCBs, RCCBs, isolators, and how to distribute power effectively and safely across different circuits in your home or workspace. Improper wiring may not only compromise protection performance but can.