A contemporary main panel receives three incoming electrical service wires and routes smaller cables and wires to subpanels and circuits throughout the house. Behind the main panel's circuit breakers, power is delivered through charged bus bars (the two bars that the. In this inspection article, we will learn about inspecting the main electrical panelboard, from the utility service to the breakers, including common components of the panelboard, and an inspection checklist. Let's begin with InterNACHI's Home Inspection Standards of Practice. At the service panel, the two hot cables from the meter base attach to lugs or terminals on the main breaker. It ensures that electricity flows. A distribution board or distribution box is where the main power supply is distributed to multiple loads. NEC Article 408 covers switchboards, switchgear, and Panelboards installation and applications.