In summary, panelboards are used to manage light, heat, or power circuits, according to the NEC (r) definition. Positioned in a cabinet or cutout box affixed to or against a wall only accessible from the front or back, they provide a safe and convenient way to distribute electricity within a facility. A single breaker serving a number of outlets can be replaced with a single-pole switch or a four-wire branch circuit, which is required by code for certain load categories.
The original purpose of the panelboard was to control the distribution of electricity to various parts of buildings. The first panels were small enough to be mounted on a wall. These were called "wall boxes" because they looked like small rooms built into the walls of houses. Each one had two sets of wires coming out of it, one set going to lights down stairs or in other areas of the house not easily reached by people, and the other set leading to outlets for several lamps or appliances. By inserting metal rods into the wall boxes, electricians could connect each lamp or appliance to its own set of wires to prevent someone from plugging something into a live current source. This is no longer necessary with modern wiring methods; all a person needs to do now is turn off the main switch for that part of the house if he or she wants to avoid using electricity at that location.
As technology improved, so did the panelboard.
A panelboard is an electrical distribution system component that separates an electrical power feed into branch circuits and provides a protective circuit breaker or fuse for each circuit in a shared enclosure. A panelboard safeguards branch circuits from overloads and short circuits. It also provides the means of connecting individual branches to different parts of a building, such as apartments or floors within a building.
Electrical power is transmitted to homes and businesses through poles and wires installed by electric companies on their property. This power is then distributed so that each part of the house or business receives its proper amount of voltage from the main line. Panelboards are located in most large buildings, including schools, hospitals, and office buildings. They can be found near the entrance to serve all areas equally well, or they may be assigned to particular rooms or groups of rooms. In small buildings with only one panelboard, it makes sense to place this equipment at the entrance so that it can service guests or patients entering from outside. In larger buildings where many panels are required, box vans parked outside entryways often contain several hundred pounds of copper wire and other equipment needed to build additional panelboards.
Electric companies install panelboards because they need to connect groups of houses together, which requires special wiring techniques called "split phases".
Definition of panelboard. A panelboard is defined by the National Electrical Code (r) as a single panel or group of panel units designed for assembly in the form of a single panel, including buses and automatic overcurrent devices, and equipped with or without switches for the control of light, heat, or power circuits. Panelboards are intended to provide protection for multiple outlets from one device or point-of-entry into the board. They can be installed inside or outside a building. The term "breaker box" is also used for panelboards.
Panelboards have become a standard feature on new buildings, allowing for many outlets to be connected to one source. Before panelboards were commonly used, people would connect several different wires together at one location, which could be confusing and dangerous if those wires were not marked properly. By using panelboards, the wiring system is made much more accessible and safe because all these different connections are now made in one place with proper insulation. These panelboards can be surface-mounted or housed within a breaker box.
Surface-mounted panelboards are attached to the wall with screws or bolts through the backplate of the panelboard. You must use a drywall screw or bolt to attach the panelboard to the wall, since wet conditions may cause corrosion of the metal inside the panelboard. Make sure that you don't put any holes in the front of the panelboard through which water could enter.