Panel Board
CSI Division 26, Electrical
A metal enclosure containing circuit breakers that distribute electrical power from a building's main service to individual circuits, the point where a building's overall power supply gets divided into the branch circuits that actually feed outlets, lighting, and equipment.
Why it matters
A panel board's labeling has to accurately identify what each breaker controls, since anyone who needs to shut off power in an emergency, or safely work on a circuit later, depends entirely on that label being correct: a mislabeled panel turns a routine shutoff into a guessing game with a live electrical system.
On a real project
An electrician sets and wires a panel board serving a floor's lighting and receptacle circuits, then labels every breaker to match the as-built circuit directory rather than a generic template, so anyone servicing the panel later knows exactly what each breaker controls.
Who this matters most to
An Electrician installs and terminates panel boards to the electrical drawings and the National Electrical Code, then verifies and labels every circuit before closeout. A Facilities Manager relies on accurate panel labeling for years after construction, since it's often the first thing consulted during any electrical troubleshooting or emergency shutoff.
Where this goes wrong
An electrical crew wires and labels a panel board quickly near the end of a rushed project, mislabeling several breakers that were shuffled during a late circuit change. Months after occupancy, a maintenance technician shuts off what the label says is a storage room circuit to make a repair, only to accidentally cut power to an occupied office instead.