Most multifamily projects include a central service point consisting of a modular metering service with SE cable distributing to each apartment where it terminates on a main log only pain. Most engineering drawings do not indicate the route between the service and the load center.
There appears to be a technical issue in the language of the code that makes the route in nearly all multifamily projects a code violation.
225.30 Prevents multiple supplies to a building and generally imposes the same limitations from NEC 230 (Services)
100 Defines a building as a separate structure or a structure separated by firewalls
Multifamily buildings generally have 1-hour-rated corridors, and each apartment is rated with 30-minute walls.
Wouldn't this make it practically impossible to design a multifamily building without violating the "letter of the law"?
NEC 225.30 Number of Supplies
A building or other structure that is served by a branch circuit or feeder on the load side of a service disconnecting means shall be supplied by only one feeder or branch circuit unless permitted in 225.30(A) through (E). For the purpose of this section, a multiwire branch circuit shall be considered a single circuit.
Where a branch circuit or feeder originates in these additional buildings or other structures, only one feeder or branch circuit shall be permitted to supply power back to the original building or structure, unless permitted in 225.30(A) through (E).
NEC 100 Definitions
Building. A structure that stands alone or that is separated from adjoining structures by fire walls. (CMP-1)
Thoughts? Does the code language need to be modified, or is there an exception to this I am missing? Leave a comment below!
The language of NEC 225.30 seems to create a practical challenge for multifamily buildings, as it often requires a single feeder to supply the entire structure. Given the typical layout of these buildings with fire-rated corridors and walls, it might be difficult to ensure strict compliance without potentially compromising the design or functionality. Perhaps a custom coursework writing service clarification or exception could be considered to address this issue.