Reducing Number of Poles: Use 1P or 1P+N circuit breakers where appropriate, reserving 2P breakers for the main switch and high-power circuits. Each circuit gives power to a certain area or equipment. Electrical distribution diagrams can help you see how things are connected. Electricians and repair teams use. Example: Need a circuit for your 1,800W microwave? Calculator Tip: Tools like Desmos' scientific calculator make light work of conversions. Just plug in your wattage and voltage—let it handle the decimals. A distribution box, also known as a distribution board, electrical panel, or breaker box, is an enclosure that houses electrical components responsible for distributing electricity throughout a building. It is a vital part and central hub of any electrical system. ① 220V load generally takes one phase line.