NEC Article 225 — Outside Branch Circuits & Feeders: Detached Garages, Sheds, and Second Buildings

NEC Article 225 is the article you're in the moment power leaves the house — a feeder or branch circuit run to a detached garage, shed, pool house, or any second structure on the property. In Hudson and Essex County this comes up constantly: EV charger in a detached garage, a workshop subpanel, landscape supply to a rear structure.

One feeder per building (225.30): a structure can generally be supplied by only ONE feeder or branch circuit. You don't run two separate circuits from the house to the same shed — you run one feeder to a subpanel in the shed and branch from there. Exceptions exist (different voltage classes, documented special conditions), but the default is one supply per building.

Disconnect required at the second building (225.31–225.33): the detached structure needs a disconnecting means at or nearest the point the feeder enters — same principle as a service disconnect. For a garage subpanel, a main-breaker subpanel satisfies this cleanly. Up to six switches or breakers can serve as the disconnect, but a single main is the clean install.

Rating floor (225.39): the feeder disconnect must be rated at least 15 A for a single branch circuit, 30 A for two or more circuits — practically, garage subpanels in NJ get 60 A or 100 A feeders because the loads (EV charger, compressor, heat) grow into them.

Grounding at the second building: the feeder carries an equipment grounding conductor with it (the modern rule — the old 3-wire feeder allowance died in 2008), AND the second building gets its own grounding electrode (ground rod) bonded to the subpanel's ground bar. Neutral and ground stay SEPARATED in the subpanel — the bond happens only at the main service. See NEC 250 grounding at separate buildings.

Overhead clearances (225.18–19): 10 ft above finished grade and sidewalks, 12 ft over residential driveways, 18 ft over public roads; 8 ft over roofs with exceptions. Tree-branch abrasion on old overhead garage feeds is one of the most common defects we find in NJ home inspections.

Underground: direct-burial UF cable at 24 inches deep, or conductors in PVC conduit at 18 inches (residential 120/240 V circuits, Table 300.5). GFCI-protected 120 V circuits to 12 inches with conditions. Practical NJ advice: run conduit — Hudson County lots get re-landscaped, and conduit lets you upsize the EV feeder later without re-trenching.

NJ permit reality: a feeder to a detached structure is permit-required electrical work in every NJ municipality — electrical permit, inspection of the trench BEFORE backfill (call the inspection in early or you're re-digging), and a final. Adding a subpanel + EV charger in a detached garage is one of the most common permits we pull in Jersey City and Hoboken.

Sizing the feeder: run the load calc for what the building will actually host — a 60 A feeder handles a Level 2 EV charger plus lights; a workshop with welder or mini-split wants 100 A. The Malfettone Load Calculator at /tools/load-calculator covers subpanel feeder sizing.