These boards typically manage voltages of 220–240V and serve loads up to 63A or 100A. Suitable for commercial buildings, factories, or any facility with a 380–415V supply. Electrical control panels and distribution boxes are the backbone of modern electrical systems. From powering homes and industrial facilities to supporting medium-voltage infrastructure, these enclosures ensure safe, efficient, and reliable power distribution. Undersized wires cause: Cable Sizing Rule: For 20A circuits, use 12-gauge wire minimum. Tool Tip: Use calculators to check voltage. How to Size a Main Panel & Load Center for 120/240V – NEC? The common voltage levels for residential applications in the USA are 120V and 240V single-phase. Three wires (identified as Hot 1 with black color, Hot 2 with red color, and Neutral with white color) from the secondary side of the. A distribution board (also known as panelboard, circuit breaker panel, breaker panel, circuit breaker, electric panel, fuse box or DB box) is a component of an electricity supply system that divides an electrical power feed into subsidiary circuits while providing a protective fuse or circuit. Switchboards are used to safely distribute electricity throughout commercial and industrial facilities.