Summary
Highlights
This video will cover the definitions of panelboards, switchboards, switchgear, and motor control centers (MCCs), which are all defined in Article 100 of the NEC and regulated by Articles 408 and 430. Despite their similarities, there are key distinctions.
A panelboard is a panel containing buses and overcurrent devices, installed in a cabinet or cutout box. These are common in residential and commercial buildings, with an example being the column width panel board, offering maximum physical protection.
A switchboard is a larger assembly than a panelboard, incorporating switches, overcurrent devices, protective devices, buses, and often instruments. It can consist of multiple sections joined together to form a complete unit.
Switchgear is a more complex enclosed assembly than a switchboard, containing primary power circuits, circuit switching, interrupting devices, or both, along with buses and connections. It typically includes meters and relays, and is usually found in industrial or large commercial facilities.
Panelboards, switchboards, and switchgear are all regulated under Article 408 of the NEC. A key difference is that panelboards are required to have overcurrent protection (408.36), while switchboards and switchgear don't have the same explicit requirement in Article 408, though it's uncommon to find them without it.
A motor control center (MCC) is an assembly with at least one enclosed section, a common power bus, and motor control units. The distinction between an MCC and switchgear can be ambiguous, often depending on how the equipment is listed. MCCs, governed by Article 430, also require overcurrent protection.
The requirements for MCCs and switchgear are often similar, and in many practical scenarios, calling a piece of equipment one or the other may not lead to significant issues, as both typically incorporate overcurrent protection in real-world installations.