"Not covered by the NEC" does not mean "no coordination required." Part 2 of this series works through NEC 90.2(A)(2), the provision that identifies installations outside the Code's scope - narrow exclusions that should never be extended beyond their stated conditions.
Plain-English Highlights
The NEC does not cover certain installations involving ships and watercraft other than floating buildings, railway rolling stock, aircraft, and most automotive vehicles; underground mines and self-propelled surface-mining machinery; railway systems used exclusively for rolling-stock power, signaling, or communications; communications equipment under exclusive utility control and located outdoors or in spaces used only for that equipment; and qualifying electric-utility installations under the utility's exclusive control.
For the utility exclusion, ownership alone is not enough - the installation must also meet an applicable location or agreement condition, such as a service drop, service lateral, or associated metering; utility property used for utility functions; a legally established easement or right-of-way; or a recognized written agreement with the governing authority. A note such as "by utility" does not automatically place equipment outside NEC scope, and informational notes provide context but are not enforceable requirements.
Why It Matters
Misapplied exclusions can leave feeders, grounding, disconnects, controls, and MEP interfaces without a clear design or inspection basis. This most often affects utility rooms, exterior transformers, communications spaces, transportation facilities, and equipment near ownership boundaries - anywhere a project team is tempted to assume an exclusion applies because the equipment looks like it belongs to someone else.
Where To Show It
E-001: code basis, exclusions, and responsibility matrix. Site plan: service point, ownership, easements, and rights-of-way. E-701: utility-to-premises boundary. Utility documents: approved service arrangement.
Do
Confirm exclusive control and a qualifying location before applying the utility exclusion. - Define the service point and ownership boundary explicitly on the drawings. - Obtain utility requirements early, before the boundary is assumed on the design. - Coordinate excluded systems with premises wiring and MEP loads at every interface.
Do Not
Treat utility ownership alone as sufficient to exclude equipment from NEC scope. - Extend an exclusion into customer-owned wiring beyond the utility's actual point of demarcation. - Use "by others" as a substitute for documented coordination. - Enforce an informational note as if it were a mandatory requirement.
Masterbuild QA Lens
Most exclusion disputes at the MEP boundary come from an assumption, not a documented determination: someone assumed "that's utility equipment" without checking the location and agreement conditions the exclusion actually requires. Confirm each of the five exclusion categories against its specific conditions before removing anything from the design and inspection basis.
Drawing / Submittal Check
At every point identified as excluded, confirm the drawings state which of the five 90.2(A)(2) categories applies and cite the specific location or agreement condition satisfied - not just a general "not in NEC scope" note.
Common Review Risk
A one-line note reads "utility equipment - not in scope" at a transformer or communications enclosure, with no supporting easement, agreement, or service-point documentation. The reviewer cannot verify an exclusion that is asserted rather than demonstrated.
When To Escalate
Escalate any equipment near a utility, communications, or transportation boundary where the applicable exclusion category is not obvious, any "by utility" note without supporting documentation, and any marina, boatyard, or transportation facility where ownership and NEC coverage are not clearly separated on the drawings.
Field Tip
At every interface, ask: Who owns it? Who controls it? Where is it located? What document establishes the boundary? If any one of those four answers is missing, the exclusion has not actually been established - it has only been assumed. Verify the locally adopted NEC edition, AHJ amendments, and utility requirements before applying this post to a real project.