210.25(B) Common Area Branch Circuits.
Code Change Summary: A new informational note provides examples of common area branch circuits.
In the 2020 NEC®, examples have been added to Section 210.25(B) to inform the code reader what a common area might be. Examples of public or common areas can include lobbies, corridors, stairways, laundry rooms, roofs, elevators, washrooms, storerooms, driveways, parking, and mechanical rooms in two family dwellings, multifamily dwellings, or multi-occupancy buildings.
Branch circuits serving lighting, central alarm, signal, and communications systems for the above locations and the like are not permitted to be supplied from the same equipment that supplies an individual dwelling unit or tenant space.
If exterior emergency lighting for a commercial strip mall was supplied from a tenant electrical panel, then the only way that it will always be energized is if that specific tenant always pays their electric bill and never moves out.
Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2020 NEC® edition of NFPA 70.
2017 Code Language:
210.25(B) Common Area Branch Circuits. Branch circuits installed for the purpose of lighting, central alarm, signal, communications, or other purposes for public or common areas of a two family dwelling, a multifamily dwelling, or a multi-occupancy building shall not be supplied from equipment that supplies an individual dwelling unit or tenant space.
2020 Code Language:
210.25(B) Common Area Branch Circuits. Branch circuits installed for lighting, central alarm, signal, communications, or other purposes for public or common areas of a two-family dwelling, a multifamily dwelling, or a multi-occupancy building shall not be supplied from equipment that supplies an individual dwelling unit or tenant space.
Informational Note: Examples of public or common areas include, but are not limited to, lobbies, corridors, stairways, laundry rooms, roofs, elevators, washrooms, store rooms, driveways (parking), and mechanical rooms.