Code
NEC 2023 for solar plan sets: what changed and what reviewers check
Short answer
The 2023 National Electrical Code continued the reorganisation of Article 690 and the interconnection rules in Article 705 that began in 2017 and 2020, with the practical effect that section numbers moved. What matters more than any individual change is that publication is not adoption: many jurisdictions are still enforcing NEC 2020 or 2017, and your set has to cite the edition actually in force.
This is an orientation piece, not a code reference. Verify every section number against the edition your jurisdiction has adopted before relying on it.
Publication is not adoption
A new NEC edition is published every three years. Adoption happens state by state and sometimes jurisdiction by jurisdiction, on no common schedule. At any moment several editions are simultaneously in force across the country, and a set drawn to the newest one can be rejected in a jurisdiction that has not adopted it.
So the first question on any job is not "what does NEC 2023 say" but "what has this jurisdiction adopted". The answer goes on the cover sheet.
Where the numbers moved
The 2017 cycle began a substantial reorganisation of PV requirements; 2020 and 2023 continued it. The effect on a plan set is mostly citation drift: material you have cited for years now lives at a different number. Two that catch people out:
- Interconnection and busbar allowances. These sat at 705.12(D) in 2017 and at 705.12(B)(3) from 2020. If your title block cites one and your jurisdiction enforces the other, expect a correction. See the 120% rule explained.
- Rapid shutdown and its labelling. The functional requirement and the placard requirement live in different sections, and both have been revised across cycles. See rapid shutdown labelling.
What reviewers actually check
In practice an electrical plan checker is looking for a small number of things, and they are the same things in every edition:
- Does the cover sheet name an edition, and is it the one we enforce?
- Is the busbar arithmetic printed, with the backfed breaker at the opposite end?
- Are conductors sized and their ampacity corrections shown?
- Is the grounding and bonding path complete on the three-line?
- Is there a label schedule with exact wording and locations?
A set that answers those five from the drawing alone goes through regardless of which edition is in force.
The practical approach
Keep a per-jurisdiction record of the adopted edition and any local amendments, check it before drawing rather than after, and cite that edition explicitly on the cover sheet. That is less glamorous than knowing the code cover to cover, and it prevents more corrections.