Review: SAMPLE-0001 · Issued: 2026-10-28 · Rev 0 · Customer: Example Solar LLC (installer, fictional) · AHJ: Anytown Building Department (fictional) · Checked against: 2023 NEC only · No site visit.
Service: 120/240 V single-phase. Main panel: 200 A busbar, 200 A main breaker at the top (end-fed), from the panel label photo.
PV: one inverter, "Example PV-7600", 7.6 kW, rated output current 31.7 A, on a 40 A backfed breaker in the bottom space of the panel (from the diagram).
Single-line diagram E-1, rev B (fictional). Panel label photo. Inverter data sheet. Photo of the panel front and the space in front of it.
Assumptions: breaker position taken from the diagram. Loads not provided, so the Article 220 sizing was not checked.
The busbar arithmetic works under the 120% rule, with the breaker where the diagram shows it. Two items need attention before inspection: the label, and the working space in front of the panel.
125 percent of the inverter output current: 31.7 A × 1.25 = 39.6 A. (The 40 A breaker is not the input; the output current is.)
(B)(1), 100% rule: 200 A + 39.6 A = 239.6 A > 200 A bus. Does not comply.
(B)(2), 120% rule: 200 A + 39.6 A = 239.6 A ≤ 1.2 × 200 A = 240 A. Meets the (B)(2) limit. The method also requires:
· the PV breaker at the end of the busbar opposite the main. The diagram shows the bottom space, the far end. Keep it there.
· the busbar sized for its loads under Article 220 (not checked: loads not provided).
· the (B)(2) label at the backfed breaker (see below).
The diagram shows no label at the PV breaker. Add one, next to the backfed breaker, with this wording or equivalent: "WARNING: / POWER SOURCE OUTPUT / DO NOT RELOCATE THIS OVERCURRENT DEVICE." It must meet 110.21(B).
From the photo, the clear depth in front of the panel appears to be about 32 in., measured from the enclosure front. Table 110.26(A)(1) requires 3 ft (36 in.) at 0–150 V to ground. Confirm by field measurement. The storage shelf in the working space must be removed regardless: 110.26(B) prohibits storage there. The width (the equipment width or 30 in., whichever is greater, with the door able to open 90°) and the height (6½ ft) appear adequate from the photo.
The locally adopted Code edition and amendments, and any utility interconnection requirements, which are outside this review.
An informational code review of the documents provided, against the 2023 NEC. It is not engineering services, a design, an inspection or an engineering seal, and it is not signed or sealed. Not reviewed: battery storage, other sources, subpanels, supply-side connections (705.11), PV-side conductor and overcurrent sizing, fault current, equipment short-circuit ratings and utility requirements. The AHJ has the final word. Liability is limited to the fee paid.