Home distribution boxes typically handle single-phase power supplies and contain 6 to 24 circuits. They include standard circuit breakers for lighting, outlets, and major appliances like water heaters and air conditioning units. However, the key to. 1) Generally, the incoming line of power distribution box adopts five wire system, that is, a, B and C three-way phase line (the general color is yellow, green and red), one way zero line (the color is light blue) and one way ground line (the color is yellow with green stripes). Whether it is residential buildings, commercial facilities or industrial sites, the. An electrical distribution box, also known as a power distribution box, panelboard, or consumer unit, is the core of an electrical system. Let's explore how these critical components work and why they deserve your attention.