The National Electrical Code (NEC) is published by NFPA on a three-year cycle. NEC 2023 (NFPA 70, 2023 edition) was published in August 2022 and has been progressively adopted by states through 2024-2026.
For solar permit designers, each NEC cycle introduces changes to Article 690 (Solar Photovoltaic Systems), Article 706 (Energy Storage Systems), Article 230 (Services), and interconnected articles that affect what goes on every plan set, every SLD, and every permit package.
Getting caught drawing to NEC 2020 when an AHJ has adopted NEC 2023 produces two outcomes: plan corrections and permit delays. Getting the changes right from the start avoids plan corrections. This post is a designer’s working reference, not a code commentary, but a change-by-change impact analysis organized by where each change appears in the permit package.
Quick answer. The NEC 2023 changes that most affect solar plan sets are: (1) the rapid shutdown marking moved from 690.56(C) to 690.12(D), and the maximum DC voltage label moved from 690.53 to 690.7(D); (2) 230.85 emergency disconnect marking, which was added in NEC 2020 and expanded in NEC 2023; (3) renumbered 705.12 and 705.11 provisions (the 120% rule is 705.12(B)(3)(2) in NEC 2020 and 705.12(B)(2) in NEC 2023); and (4) new battery disconnect marking in 706.15(E). Adoption differs by state, so verify your AHJ’s adopted edition before submitting any plan set.
TL;DR
- Adoption is not uniform. Our state matrix (26 September 2026) lists Washington, Oregon and Texas on NEC 2023, California on the 2025 CEC (NEC 2023 basis) from 1 January 2026, Florida and North Carolina on NEC 2020, and Arizona set by the city or county.
- NEC 230.85 (emergency disconnect for one- and two-family dwellings) was added in NEC 2020, not 2023. NEC 2023 expanded its marking: red background, white letters at least 1/2 in. high, and a plaque or directory rule.
- The rapid shutdown marking moved from 690.56(C) in NEC 2020 to 690.12(D) in NEC 2023, and the maximum DC voltage label moved from 690.53 to 690.7(D).
- Article 706.15 expanded the disconnecting means rules in 2023, including new battery disconnect marking in 706.15(E).
- The 120% rule is cited at 705.12(B)(3)(2) in NEC 2020 and 705.12(B)(2) in NEC 2023. The arithmetic did not change; the section number did.
- Confirming the AHJ's actual adopted edition before drawing, not assuming statewide adoption is uniform, is the single fastest way to avoid a correction cycle.
NEC Adoption Timeline: Which States Use Which Edition
The NEC is a model code. Each state (and sometimes each AHJ within a state) adopts it by reference at a specific edition. Misidentifying the adopted edition is one of the most common causes of plan corrections. Use the dated current NEC edition by state matrix as a starting point, then confirm the project AHJ and transition rule.
| State | Baseline found on 26 September 2026 | Effective date or note |
|---|---|---|
| Colorado | 2026 NEC | August 1, 2026 |
| Washington | 2023 NEC through WAC 296-46B-010 | April 1, 2024; the 2026 NEC starts December 31, 2026 |
| Oregon | 2023 NEC through the 2023 Oregon Electrical Specialty Code | October 1, 2023 |
| California | 2023 NEC through the 2025 California Electrical Code | January 1, 2026 |
| Texas | 2023 NEC | September 1, 2023; municipal permits may apply |
| Florida | 2020 NEC through the Eighth Edition Florida Building Code | December 31, 2023 |
| New York | Split authority; New York City uses an amended 2020 NEC | City code effective December 21, 2025 |
| New Jersey | 2023 NEC through the Uniform Construction Code | August 17, 2026 |
| Massachusetts | 2026 NEC through 527 CMR 12.00 | April 24, 2026 |
| Arizona | Edition set by the city or county | Local ordinance controls |
| Illinois | Edition set by the local authority | Local ordinance controls |
| North Carolina | 2020 NEC through the North Carolina Electrical Code | November 1, 2021 |
Source: our NEC edition by state matrix, which links each row to the state’s own rule. Adoption dates change, so open the matrix and the AHJ’s page before you rely on a row.
Watch out, verify before drawing. NEC adoption is not always immediate at the state level. Some AHJs within states that have "adopted" NEC 2023 still review against their previous edition during a transition period. Before starting any permit package, confirm the specific AHJ's adopted code edition, either from the AHJ's official website, the online permit portal, or a direct inquiry to the building department. Drawing to the wrong edition wastes 4-14 business days in a correction cycle.
Article 690 (Solar Photovoltaic Systems): Key NEC 2023 Changes
The NEC text is behind a login at NFPA. This section rests on IAEI Magazine (J. A. Kraft, January 2023; John Wiles, March 2023), Mike Holt’s 2023 NEC material and Solar Power World (Christian Eder, Fronius USA, January 2024). Read the adopted text before you cite a section on a drawing.
690.12: Rapid Shutdown System (RSS)
How the rule developed (IAEI, Kraft, January 2023):
- NEC 2017 defined the array boundary as 1 foot from the array in all directions. Controlled conductors outside it, and conductors more than 3 feet inside a building, had to reach 30 V or less within 30 seconds. Conductors inside the boundary had an 80 V limit from 1 January 2019.
- NEC 2020 added the phrase “PV hazard control system” to 690.12(B)(2)(1), with an exception that refers to UL 3741.
- NEC 2023 690.12(B)(2)(1) requires a PV hazard control system (PVHCS) installed to provide electric shock hazard control for firefighters. 690.12(B)(2)(2) still limits conductors inside the boundary to 80 V within 30 seconds. The old (B)(2)(3) was removed because the UL 3741 standard absorbed it. Where a PVHCS needs initiation, the initiation device in 690.12(C) performs it.
Marking moved (Wiles, IAEI, March 2023; Holt, 2023): the rapid shutdown label left 690.56(C) and now sits in 690.12(D). It shows the location of all initiation devices, near the service equipment or at an approved readily visible location.
Carports, trellises and shade structures: NEC 2023 added an exception to 690.12 for them (Eder, Solar Power World, January 2024). Ask the AHJ before you delete the labels on such a structure.
SLD Impact:
- Identify the rapid shutdown equipment by make and model on the SLD, and cite the section for the adopted edition
- Show the array boundary on the roof plan with its distance and the edition it comes from
- Label the initiation device location
For the full walkthrough, see our rapid shutdown compliance guide.
690.7(D) and 690.56: Labels That Moved
- Maximum DC voltage label: 690.53 in NEC 2020, 690.7(D) in NEC 2023. The installer provides it at the DC PV system disconnect, the power conversion equipment or associated distribution equipment (Wiles, IAEI, March 2023).
- Power source marking: in NEC 2023, 690.56 points to 705.10. The 705.10 text allows a label as well as a plaque or directory, and adds emergency phone numbers for off-site entities that service the sources (ElectricalLicenseRenewal and Mike Holt, 2024).
Our solar labels and placards guide lists each label by edition, section, wording and location.
SLD Impact: Copy label wording and section numbers from the edition the AHJ has adopted. A label schedule that mixes 2020 and 2023 numbers invites a plan correction.
NEC 230.85: Emergency Disconnect (Added in NEC 2020, Marking Expanded in NEC 2023)
NEC 230.85 is not new in NEC 2023. It was added in NEC 2020, and the 2020 text already carried the three marking wordings listed below (ElectricalLicenseRenewal reproduction of the 2020 text, checked 31 October 2026). John Wiles also flagged the 2020 rule for one- and two-family dwellings in IAEI Magazine. What NEC 2023 changed is the marking. Our solar labels and placards guide lists both editions side by side.
What NEC 230.85 covers in the sources we read:
- It applies to one- and two-family dwellings.
- The marking wording depends on the device: “EMERGENCY DISCONNECT, SERVICE DISCONNECT”, “EMERGENCY DISCONNECT, METER DISCONNECT, NOT SERVICE EQUIPMENT” or “EMERGENCY DISCONNECT, NOT SERVICE EQUIPMENT”. The 2020 text already had all three.
- NEC 2020: markings comply with 110.21(B).
- NEC 2023: red background with white letters at least 1/2 in. high, and a plaque or directory when the other source isolation disconnects are not adjacent. These details come from the New York Electrical Inspection Agency 2023 summary. We did not find them in the 2020 text we read.
Where the disconnect goes and what triggers it: We have not verified the location rule or whether a retrofit or a service upgrade triggers 230.85 from the code text, so we do not state either here. Wiles noted for the 2020 edition that it is unclear where the PV tie-in sits relative to the emergency disconnect. Ask the AHJ before you draw the order of devices.
Plan Set Impact:
- One- and two-family dwellings: Show the emergency disconnect on the SLD and site plan where the adopted edition requires it, with the wording for the device type.
- Retrofit solar or a service upgrade: Confirm with the AHJ whether 230.85 is triggered. Interpretation varies by jurisdiction.
- Label callout: Add the marking wording to the label schedule, for example “EMERGENCY DISCONNECT, SERVICE DISCONNECT” for a service disconnect, and use the 2023 color and size rule where the AHJ has adopted NEC 2023.
NEC 2020
- 230.85 added
- Three marking wordings by device type
- Markings comply with 110.21(B)
NEC 2023
- Same three wordings
- Red background, white letters at least 1/2 in.
- Plaque or directory when other source isolation disconnects are not adjacent
- Retrofit and service upgrade triggers: confirm with the AHJ
Article 706 (Energy Storage Systems): NEC 2023 Changes
Article 706 covers storage systems above 1 kWh that cycle in normal use. The items below come from Ryan Mayfield (EC&M, 15 February 2024), Mike Holt (January 2024) and our battery retrofit guide. Check the code book for exact wording.
- 706.15 disconnecting means: expanded in 2023. The ESS disconnect is within the ESS, within sight and not more than 10 ft away, or lockable. For one- and two-family dwellings, 2023 adds an emergency shutdown function with an initiation device outside the building (Mayfield, EC&M, 2024). Cite 706.15 and check the book for the subsection letter.
- 706.15(C) marking: “ENERGY STORAGE SYSTEM DISCONNECT”, with source identification, nominal voltage, available fault current, an arc-flash label and the calculation date, with an exception for one- and two-family dwellings (Holt, 2024).
- 706.15(E) battery disconnect marking: new in 2023 where the battery is separate from the ESS electronics and serviced in the field (Mayfield, EC&M, 2024).
- 706.7 commissioning: split into commissioning and maintenance in 2023. Commissioning requirements do not apply to one- and two-family dwellings.
- Listing and fire code: IRC R328.2 requires a residential ESS to be listed and labeled to UL 9540, and individual units are limited to 20 kWh under the 2021 IRC (UL Code Authority summary). This comes from the IRC, not from NEC 2023. Our NEC 706 BESS permit guide and NFPA 855 guide cover the fire side.
Article 705 (Interconnected Electric Power Production Sources): NEC 2023 Changes
Article 705 governs how solar systems interconnect with utility power. NEC 2023 revisions affect the 120% busbar rule and multi-source configurations.
705.12(B): Load-Side Connection (120% Rule)
Same arithmetic, new section number. The 120% method is 705.12(B)(3)(2) in NEC 2020 and 705.12(B)(2) in NEC 2023. The load-side busbar rules sit at 705.12(B)(3) in 2020 and 705.12(B) in 2023 (John Wiles, IAEI Magazine, March and December 2023; ElectricalLicenseRenewal reproduction of the 2020 text). Solar OCPD ≤ (1.20 × busbar rating) − main breaker OCPD rating, with the solar breaker at the opposite end of the busbar from the main.
SLD Impact:
- The 120% calculation box on the SLD must show every source OCPD on the busbar (solar, BESS and any generator)
- Cite the section for the edition the AHJ has adopted
The NEC 705.12 interconnection guide covers the complete calculation methodology.
705.11: Supply-Side Connection
Our supply-side connection guide compares the 2020 and 2023 subsections in detail.
What the sources show:
- The subsection letters moved. In NEC 2020 conductors are in (B), the overcurrent device in (C), connections in (D) and ground-fault protection in (E). In NEC 2023 connections are in (C), the disconnect in (D), bonding is a new (E) and overcurrent protection is in (F) (Wiles, IAEI Magazine, March 2023; Holt, EC&M, September 2024).
- NEC 2020 set fixed overcurrent device distances. NEC 2023 reportedly has no fixed maximum length (Mayfield Renewables, February 2024).
- The 6 AWG copper and 4 AWG aluminum minimum conductor sizes are reported in both editions. We did not confirm the NEC 2023 wording from a primary text.
The next cycle is already out: see what NEC 2026 changes for solar designers.
Changes Affecting the SLD: Summary Checklist
For permit designers updating drawings from NEC 2020 to NEC 2023 standard:
Update NEC Edition Reference
Change "Designed to NEC 2020" → "Designed to NEC 2023 (NFPA 70, 2023 Edition)" in the title block or code compliance note. AHJs reviewing NEC 2023 plan sets will check this first.
Show the NEC 230.85 Emergency Disconnect (One- and Two-Family Dwellings)
For one- and two-family dwellings: show the emergency disconnect on the SLD and site plan and label it per NEC 230.85 for the adopted edition (NEC 2023 added a red background and white letters at least 1/2 in. high). Confirm with the AHJ whether retrofit installations or service upgrades trigger it.
Update Rapid Shutdown Marking (690.12)
Cite the rapid shutdown marking at 690.12(D) instead of 690.56(C), and the maximum DC voltage label at 690.7(D) instead of 690.53. Identify the rapid shutdown equipment, or the PV hazard control system and its UL 3741 certificate, on the SLD, and show the array boundary on the roof plan.
Update 120% Calculation Box (705.12)
For systems with both solar and BESS on load-side: ensure the 120% calculation includes every source breaker on the busbar, both the PV inverter OCPD and the BESS inverter OCPD. Update the section citation from "705.12(B)(3)(2)" (NEC 2020) to "705.12(B)(2)" (NEC 2023) if the AHJ requires section references.
Update BESS Documentation (706)
For BESS-included systems: show the ESS disconnect per 706.15, add the battery disconnect marking in 706.15(E) where it applies, and put the UL 9540 listing on the cut sheet. Check the IRC R328 and fire code limits for the battery location.
Reviewers also check the stamp block and sheet references; see how to read a PE-stamped solar drawing.
NEC 2023 Changes Outside Article 690/706
Several articles outside the main solar articles have changes relevant to solar installations.
Article 230, Services:
- NEC 230.85 (emergency disconnect), added in NEC 2020 with the marking expanded in NEC 2023, covered above
- NEC 230.82(6) (2020) and the Article 230 Parts VI to VIII reference (2023) govern the disconnect for supply-side solar taps; see our supply-side connection guide
Comparison Summary: NEC 2020 vs NEC 2023 Solar Impact
| Change | NEC 2020 | NEC 2023 | Impact on Plan Sets |
|---|---|---|---|
| Emergency disconnect (230.85) | Added in NEC 2020; three marking wordings | Same wordings; red background, white letters at least 1/2 in.; plaque or directory rule | Add to SLD, site plan and label schedule for one- and two-family dwellings |
| Rapid shutdown marking | 690.56(C) | 690.12(D) | Update section citations on the label sheet |
| Maximum DC voltage label | 690.53 | 690.7(D) | Update section citation on the label sheet |
| 120% calculation | 705.12(B)(3)(2) | 705.12(B)(2) | Update the section citation; show every source OCPD in the calculation box |
| ESS disconnect | 706.15 | 706.15 expanded; 706.15(E) battery disconnect marking added | Show the disconnect and its marking on the SLD and ESS sheet |
Related Heaven Designs Resources
Confirm the adopted NEC edition and local amendments for the AHJ before drafting, and name the edition on the cover sheet.
- Solar Permit Design (USA): permit plan sets for US installers.
- Solar 3D Pre-Design: sales-stage 3D layout and preliminary SLD.
- NEC 705.12 interconnection guide: the 120% rule with worked examples.
- NEC 706 BESS permit guide: Article 706 for solar plus storage.
- NEC 2023 rapid shutdown compliance guide: 690.12 walkthrough.
- NEC 2017 to 2023, what changed for solar designers: the multi-cycle view.
The NFPA 70 (NEC) official page is the authoritative source for NEC text.
Glossary: NEC 705, AHJ, Rapid Shutdown, IBC, IRC.
FAQ
What is the most important NEC 2023 change for residential solar permit designers?
NEC 230.85 (emergency disconnect for one- and two-family dwellings) is not new in NEC 2023. It was added in NEC 2020. NEC 2023 expanded its marking with a red background, white letters at least 1/2 in. high, and a plaque or directory when other source isolation disconnects are not adjacent (New York Electrical Inspection Agency 2023 summary).
Show the device and its marking wording on the SLD and site plan where the adopted edition applies. Missing or wrong label wording is a plan-check item our labels guide covers.
Does NEC 230.85 apply to existing homes getting solar?
We have not verified from the code text whether a retrofit or a service upgrade triggers NEC 230.85, so we do not give a rule. Interpretation varies by AHJ. Confirm with the specific AHJ before designing the system, especially when the job includes a service panel upgrade.
What changed in NEC 2023 for solar+battery storage systems?
NEC 2023 expanded the 706.15 disconnecting means rules, including an emergency shutdown function for one- and two-family dwellings, and added battery disconnect marking in 706.15(E) (Mayfield, EC&M, February 2024; Holt, January 2024). Document the UL 9540 listing for the battery on the cut sheet, and check the IRC R328 or fire code limits for the location.
Is NEC 2023 adopted in California?
California adopts the NEC through the California Electrical Code (CEC) on a separate schedule. Our state matrix (26 September 2026) lists California on the 2023 NEC through the 2025 CEC, effective 1 January 2026. Before that date, the 2022 CEC (NEC 2020 basis) applied. Check the filed city or county amendments and the local transition rules for a project’s permit date.
How do I find out which NEC edition my AHJ uses?
Check the AHJ’s building department website for a code adoptions or applicable codes page, and many permit forms list the edition. If the AHJ does not publish it, ask the plan check counter which NEC edition it enforces and note the answer with the date. Our state matrix is a starting point, not a substitute.
What is the difference between the NEC 2020 and NEC 2023 section numbers for the 120% rule?
In NEC 2020, the 120% method is at section 705.12(B)(3)(2). In NEC 2023, it is at 705.12(B)(2). The arithmetic (solar OCPD ≤ 1.20 × busbar rating − main breaker OCPD) is the same; the section number changed (John Wiles, IAEI Magazine, 2023).
AHJs enforcing NEC 2023 may expect plan set citations to reference 705.12(B)(2). Using an older section number can trigger a correction, so update section references when moving templates to NEC 2023. Our NEC 705.12 guide lists the numbering for 2017, 2020 and 2023.