The main electrical panel, commonly called the breaker box, is the central distribution point for all power inside the home. Distribution substations connect to the transmission system and lower the transmission voltage to medium voltage ranging between 2 kV and 33 kV. Most homes have three-wire service—two hot wires and one neutral. Electrical utilities deliver electricity through a masthead at the roof. The main service disconnect feeds the panel's two main bus bars, which carry the two 120-volt “hot” legs of power. It involves a series of components and processes that ensure an efficient and reliable electrical power supply at the. The electricity supply chain consists of three primary segments: generation, where electricity is produced; transmission, which moves power over long distances via high-voltage power lines; and distribution, which moves power over shorter distances to end users (homes, businesses, industrial sites. The terms primary, secondary, and tertiary distribution boxes are relative. Let's make an example for clarity: A newly constructed residential area introduces a 10kV power line to a substation. From the transformer's low-voltage side (0.
