Solar Permitting Guide: NEC Requirements, AHJ Approval Process, and Inspection Checklist

Reading time: ~15 min read

Navigating the solar permitting process is one of the most critical and often challenging aspects of PV system installation. The Authority Having Jurisdiction (AHJ) — typically the local building or electrical department — is responsible for reviewing plans, issuing permits, and conducting inspections to verify compliance with the National Electrical Code (NEC) and local amendments. This guide provides electricians, solar installers, and contractors with a comprehensive framework for preparing permit applications, understanding NEC Article 690 and 705 requirements, passing inspections on the first attempt, and avoiding common rejection reasons.

PES Supply stocks 50,000+ SKUs from 169 authorized brands, including all the disconnects, electrical accessories, conduit, and charge controllers needed to meet code requirements. Standard delivery is 7-10 business days.

1. Understanding the Regulatory Framework

Solar PV installations in the United States are governed by a layered system of codes and standards. The NEC, published by the National Fire Protection Association (NFPA), is the primary electrical code adopted by most states and municipalities. Article 690 covers solar PV systems rated less than 5,000 kW, while Article 691 addresses large-scale PV electric supply stations rated 5,000 kW or greater. Article 705 governs the interconnection of distributed energy resources (DER) with electric power production and distribution networks ([NFPA Blog](https://www.nfpa.org/news-blogs-and-articles/blogs/2024/02/26/the-importance-of-electrical-codes-for-safer-ess-and-pv-installations)).

The NEC is adopted and enforced at the state and local level, meaning that AHJs may be operating under different editions of the code. The NFPA maintains a map showing which NEC edition is enforced in each state ([NFPA NEC Enforcement Maps](https://www.nfpa.org/education-and-research/electrical/nec-enforcement-maps)). As of 2026, most jurisdictions have adopted the 2023 NEC, though some are still on the 2020 edition and early adopters are moving to the 2026 edition. Always verify which code edition your AHJ enforces before preparing permit documents.

2. NEC Article 690 Key Requirements

Article 690 of the NEC contains the specific requirements for solar photovoltaic systems. The following sections are most frequently cited during plan review and inspection.

2.1 Scope (690.1)

Article 690 applies to solar PV systems that exceed 30 volts or 8 amperes, including array circuits, inverters, and controllers for such systems. This applies to systems interactive with other electric power sources, stand-alone systems, or systems with energy storage. Systems not exceeding these thresholds are exempt from most Article 690 requirements ([NFPA NEC Code Development](https://www.nfpa.org/codes-and-standards/nfpa-70-standard-development/70)).

2.2 Maximum Voltage (690.7)

The maximum voltage for PV source circuits is determined by summing the rated open-circuit voltage (Voc) of series-connected modules and correcting for the lowest expected ambient temperature. For systems operating above 100 volts, the correction factor must be applied based on the ASHRAE minimum ambient temperature for the installation location. PV system DC circuits shall not exceed 1,000 volts on one- and two-family dwellings. For commercial buildings, the limit is 1,000 volts within or originating from arrays on buildings; ground-mount arrays may operate up to 1,500 volts DC.

2.3 Circuit Sizing and Current (690.8)

NEC 690.8 specifies how PV circuit currents must be calculated for conductor and overcurrent device sizing:

• Maximum current (PV source circuits): The sum of the short-circuit current ratings (Isc) of the PV modules connected in parallel, multiplied by 125%.
• Maximum current (PV output circuits): The continuous current rating of the inverter output, multiplied by 125%.
• Conductor ampacity: Must be not less than 125% of the maximum current, after applying all correction and adjustment factors.
• For PV systems with an inverter generating capacity of 100 kW or greater: A documented and stamped PV system design using an industry-standard method may be used to determine maximum current.

For bifacial modules, the bifacial short-circuit current ratings are used instead of the monofacial values, reflecting the additional rear-side energy contribution ([NFPA NEC P04 First Draft](https://docinfofiles.nfpa.org/files/AboutTheCodes/70/70_A2025_NEC_P04_FD_PIResponses.pdf)).

2.4 Rapid Shutdown (690.12)

Rapid shutdown requirements are among the most scrutinized code provisions during inspection. NEC 690.12 requires that PV system circuits installed on or in buildings include a rapid shutdown function to reduce shock hazards for emergency responders.

Rapid Shutdown Boundaries

• Outside the array boundary (1-foot rule): PV conductors more than 1 foot (305 mm) from the array must be reduced to 80 volts or less within 30 seconds of rapid shutdown initiation.
• Inside the array boundary: PV conductors within the array boundary must be reduced to 80 volts or less within 30 seconds, or the array boundary must be reduced to 300 volts or less.

Initiation Devices

Rapid shutdown initiation devices must be readily accessible and may consist of:

• The service disconnecting means.
• The PV system disconnecting means.
• A listed switch plainly indicating the "off" or "on" position.

For one- and two-family dwellings, initiation devices must be located at a readily accessible outdoor location outside the building. The equipment controlling rapid shutdown must be listed or evaluated for the purpose, typically complying with UL 3741 for PV hazard control systems ([NFPA NEC P04 Second Draft](https://docinfofiles.nfpa.org/files/AboutTheCodes/70/70_A2025_NEC_P04_SD_PCSubmittals.pdf)).

2.5 Arc-Fault Circuit Protection (690.11)

PV systems with DC circuits operating at 80 volts or greater between any two conductors must be protected by a listed PV arc-fault circuit interrupter or equivalent listed system components. This requirement applies to most residential and commercial string inverter systems.

3. NEC Article 705: Interconnection Requirements

Article 705 governs the interconnection of PV systems and other distributed energy resources with the utility grid. Key requirements relevant to the permitting process include:

3.1 Point of Connection

• Interconnection must be made at a dedicated breaker or fused disconnect on the load side of the service disconnecting means.
• The interconnection point must not interfere with the normal operation of the utility service.
• For multiple interconnected sources, each source must have its own disconnecting means.

3.2 Disconnecting Means (705.20)

Each power production source must have a disconnecting means that:

• Is manually operable and externally operable without exposed live parts.
• Is lockable open in accordance with NEC 110.25.
• Is sized not smaller than 6 AWG copper or 4 AWG aluminum.
• Is installed in accordance with NEC 230.30 or 230.43.

3.3 System Labeling

Article 705 requires specific labeling at the service equipment and interconnection point, including the presence of interconnected power sources and the location of disconnecting means.

4. Permit Application Documents

A complete solar permit application typically requires the following documents. Requirements vary by AHJ, so always check the local jurisdiction's solar permitting checklist before submission.

4.1 Required Submittals

4.2 One-Line Diagram Requirements

The one-line diagram is the most critical document in the permit application. A compliant one-line diagram must include:

• PV array configuration (series modules per string, parallel strings).
• Module electrical ratings (Voc, Isc, Vmp, Imp, temperature coefficient for Voc).
• Calculated maximum system voltage (cold-temperature corrected Voc).
• Calculated maximum circuit current (Isc × 125%).
• Conductor types, sizes, and temperature ratings (e.g., PV Wire 10 AWG, 90°C).
• Conduit type and fill calculations where applicable.
• Overcurrent protection device ratings and locations.
• Disconnecting means (DC and AC) with labeling.
• Inverter make, model, and AC output rating.
• Grounding electrode system and equipment grounding conductor sizes.
• Point of interconnection (breaker size, busbar rating, main breaker rating).
• Rapid shutdown equipment location and boundaries.
• All required warning and identification labels.

5. AHJ Submission Process

The permit submission and approval process varies by jurisdiction but generally follows these steps:

5.1 Pre-Application

1. Verify AHJ requirements: Contact the local building/electrical department or visit their website to obtain the solar permitting checklist, fee schedule, and specific local amendments.
2. Confirm NEC edition: Determine which NEC edition the AHJ has adopted, as requirements differ between the 2020 and 2023 editions ([NFPA NEC Enforcement Maps](https://www.nfpa.org/education-and-research/electrical/nec-enforcement-maps)).
3. Check utility interconnection requirements: Submit interconnection application to the serving utility in parallel with the building permit, as utility approval may take weeks.
4. Verify zoning and HOA restrictions: Some jurisdictions have setback, screening, or aesthetic requirements for solar installations.

5.2 Submission

1. Submit complete application package including all required documents listed in Section 4 above.
2. Pay permit fees, which are typically based on system size (per kW), valuation, or a flat fee. Many jurisdictions have adopted streamlined solar permit fees per the Solar ABCs expedited permitting process.
3. Allow review time: Plan review typically takes 2–4 weeks, though some AHJs offer expedited review for residential systems following the Solar ABCs standard.

5.3 Revisions and Resubmittal

If the plan reviewer identifies deficiencies, a correction notice will be issued. Address all comments, revise the plans, and resubmit. Common revision requests include:

• Updated one-line diagram with missing ratings or calculations.
• Structural engineering letter for roof-mounted systems on older roofs.
• Corrected busbar/load calculations per NEC 705.12.
• Added rapid shutdown details and equipment listings.
• Corrected conductor ampacity after temperature derating.

5.4 Permit Issuance and Inspection Scheduling

Once the permit is issued, the installation may begin. Inspections are typically scheduled in stages:

• Rough-in electrical inspection: After conduit, wiring, and junction boxes are installed but before panels are closed.
• Racking and mounting inspection: After racking is installed (some AHJs combine this with rough-in).
• Final electrical inspection: After all equipment is installed, labeled, and ready for interconnection.
• Utility interconnection inspection: Performed by the utility after the final inspection passes and the Permission to Operate (PTO) is issued.

6. Common Permit Rejection Reasons

Understanding the most frequent rejection reasons helps contractors prepare cleaner applications and reduce review cycles.

7. Inspection Checklist

The following inspection checklist covers the most commonly verified items during solar PV electrical inspections. Use this checklist during pre-inspection self-verification to increase first-time pass rates.

7.1 General

• [ ] Permit and approved plans on site.
• [ ] Installer license available for inspector verification.
• [ ] All equipment installed per manufacturer instructions.
• [ ] Working clearances of at least 3 feet maintained in front of all equipment (NEC 110.26).
• [ ] Equipment not installed in bathrooms or hazardous locations (NEC 690.4).

7.2 PV Array

• [ ] Modules match approved plans (make, model, count).
• [ ] Modules secured to racking per manufacturer instructions.
• [ ] Racking structurally attached per engineering letter.
• [ ] Roof penetrations properly flashed and sealed.
• [ ] Fire access pathways maintained (36-inch minimum width, gutter to ridge).
• [ ] Ridge setback maintained (18 inches for arrays covering ≤33% of roof area).
• [ ] Module-level rapid shutdown devices installed (if applicable).

7.3 DC Wiring

• [ ] PV Wire or USE-2 cable used for exposed array wiring (NEC 690.31(C)).
• [ ] Cables supported and secured at intervals not exceeding 24 inches (600 mm).
• [ ] Cables not in contact with roofing material or sharp edges.
• [ ] DC conductors inside buildings in metal raceways or MC cable (NEC 690.31(E)).
• [ ] DC conduit runs minimize length and avoid living spaces where possible.
• [ ] MC4 connectors properly mated and torqued (no visible mismatched brands).

7.4 DC Disconnect and Overcurrent Protection

• [ ] DC disconnect rated for DC voltage and current (NEC 690.13).
• [ ] DC disconnect marked "PV SYSTEM DISCONNECT" (NEC 690.13(C)).
• [ ] Disconnect lockable in the open position (NEC 110.25).
• [ ] Overcurrent protection devices rated per NEC 690.9 and marked "PV" or "Photovoltaic".
• [ ] Combiner box fuses properly sized and installed.

7.5 Inverter and AC Wiring

• [ ] Inverter listed to UL 1741 (SB or SBW for current grid support requirements).
• [ ] Inverter installed per manufacturer clearance requirements.
• [ ] AC disconnect accessible and within sight of inverter (where required).
• [ ] AC conductors sized at 125% of inverter output current.
• [ ] GFDI or ground-fault protection functioning per NEC 690.41(B).
• [ ] Arc-fault protection enabled (NEC 690.11) for systems ≥80 V DC.

7.6 Grounding and Bonding

• [ ] Module frames bonded to racking (UL 2703 listed bonding devices).
• [ ] Equipment grounding conductors sized per NEC 250.122 and Table 250.122.
• [ ] Grounding electrode conductor connected to building grounding electrode system (NEC 690.47).
• [ ] Bonding jumpers installed across all racking splices and rail joints.
• [ ] Inverter grounding per manufacturer instructions.

7.7 Rapid Shutdown

• [ ] Rapid shutdown equipment listed (UL 3741 or UL 1741 PVRSE).
• [ ] Initiation device installed at readily accessible outdoor location (dwellings).
• [ ] Rapid shutdown boundary clearly marked on plans and site.
• [ ] "PV SYSTEM DISCONNECT" and rapid shutdown labels installed.
• [ ] System tested and verified to reduce voltage to 80 V within 30 seconds.

7.8 Labeling

• [ ] All labels engraved or printed on weather-resistant material.
• [ ] DC disconnect labeled "PV SYSTEM DISCONNECT" (NEC 690.13(C)).
• [ ] AC disconnect labeled with inverter output rating and operating voltage.
• [ ] Main service panel labeled "SOLAR ELECTRIC SYSTEM CONNECTED" or equivalent (NEC 705.10).
• [ ] Rapid shutdown label at service disconnecting means.
• [ ] Operating voltage, current, and short-circuit current at DC disconnect.
• [ ] Point of interconnection labeled with maximum AC operating current.

8. Labeling Requirements in Detail

NEC Article 690 and 705 mandate specific labeling at multiple points in the PV system. Labels must be permanent, weather-resistant (for outdoor locations), and clearly legible. The following table summarizes the required labels:

9. Fire Code and Roof Access Requirements

In addition to NEC requirements, solar installations must comply with fire code provisions for roof access. The International Residential Code (IRC) Section R324 and the International Fire Code (IFC) Section 1205 establish requirements for:

• Access pathways: Minimum 36-inch (914 mm) wide pathways from gutter to ridge on each roof slope with PV modules.
• Ridge setback: Modules must be set back from the ridge line to allow for fire service ventilation. When panels cover 33% or less of the plan view roof area, the setback is at least 18 inches (457 mm) from the ridge ([NFPA Blog](https://www.nfpa.org/news-blogs-and-articles/blogs/2024/02/29/residential-solar-panel-requirements)).
• Middle pathway: For arrays exceeding certain sizes, a 36-inch pathway may be required through the middle of the array.
• Maximum array size: Some jurisdictions limit continuous array dimensions to 150 feet in either direction.

10. Utility Interconnection Process

Parallel to the building permit process, the utility interconnection application must be submitted to the serving utility. The interconnection process typically involves:

1. Application submission: Submit system specifications, single-line diagram, and inverter certification documents.
2. Utility review: The utility verifies grid compatibility, protection settings, and meter requirements.
3. Approval: The utility issues an interconnection approval or Permission to Operate (PTO) after the local inspection passes.
4. Meter installation: The utility installs a bi-directional or net meter (if not already present).
5. System energization: The system may be energized only after PTO is received.

The inverter must be listed and certified to UL 1741, which includes grid-support functions such as voltage and frequency ride-through, anti-islanding, and smart inverter functions. UL 1741-SB supplements the base standard with additional grid support requirements that many states now mandate ([NFPA NEC P04 Second Draft](https://docinfofiles.nfpa.org/files/AboutTheCodes/70/70_A2025_NEC_P04_SD_PCSubmittals.pdf)).

11. Expedited Permitting: The Solar ABCs Standard

The Solar America Board for Codes and Standards (Solar ABCs) developed an expedited permitting process for small residential PV systems (under 10 kW). Many AHJs have adopted this streamlined process, which features:

• A simplified standard permit application form.
• Pre-approved standard mounting details for common roof types.
• A simplified one-line diagram template.
• Reduced plan review time (often same-day or next-day approval).
• Standardized fee structures.

Contractors should ask their AHJ whether they participate in the Solar ABCs expedited process or a similar streamlined program. The U.S. Department of Energy's Solar Power in Your Community guide also encourages jurisdictions to adopt streamlined permitting to reduce solar soft costs ([DOE Solar Rooftop Potential](https://www.energy.gov/cmei/systems/solar-rooftop-potential)).

12. NEC 2023 and 2026 Code Changes Affecting Permitting

The NEC is updated every three years. Key changes in recent editions that affect the permitting process include:

2023 NEC Changes

• Rapid shutdown: Clarified requirements for PV hazard control systems (PVHCS) and equipment (PVHCE), with reference to UL 3741.
• Bifacial modules: New requirements for calculating maximum current using bifacial short-circuit current ratings.
• DC surge protection: PV system DC circuits must have SPDs marked as "PV SPD" installed at DC combiners, power converters, or DC disconnecting means.
• Functional grounding: Updated terminology and requirements for PV system DC circuit grounding configurations.
• PV wire listing: Type PV wire must be listed per UL 4703; distributed generation (DG) cable must be listed per UL 3003.

2026 NEC Changes (Proposed)

• OCPD terminology: Overcurrent protective devices (OCPDs) terminology standardized throughout Article 690.
• PV wire strands: New Table 690.31(C)(4) specifying minimum strand counts for PV wire used on tracking arrays.
• Bonding devices: Clarified requirements that bonding devices for PV modules must be listed, labeled, and identified for specific modules, referencing UL 2703.
• Flexible grounding conductors: Expanded requirements for flexible equipment grounding and bonding conductors on tracking PV arrays.
• Large-scale grounding: New section 690.43(E) requiring grounding electrode system details in documentation for large-scale PV systems.

The NFPA's code development process, including First Draft, Second Draft, and TIA (Tentative Interim Amendment) cycles, is documented on the NFPA website ([NFPA NEC Code Development](https://www.nfpa.org/codes-and-standards/nfpa-70-standard-development/70)).

Conclusion

Successful solar permitting requires a thorough understanding of NEC Articles 690 and 705, careful preparation of complete and accurate permit documents, and attention to the specific requirements of the local AHJ. By following the guidelines in this article and using the inspection checklist for pre-inspection verification, contractors can reduce rejection rates, minimize review cycles, and pass inspections on the first attempt. Staying current with NEC code changes — particularly rapid shutdown, bifacial module requirements, and surge protection — is essential for maintaining compliance as codes evolve.

PES Supply supports contractors with 50,000+ SKUs from 169 authorized brands. Browse our full selection of disconnects, electrical accessories, conduit, inverters, and charge controllers to meet all your permitting and installation requirements. Standard delivery is 7-10 business days.

Frequently Asked Questions

Shop This Article

Ready to build your system? PES Supply stocks 50,000+ SKUs from 169 authorized brands, with delivery in 7-10 business days. Here are the products mentioned in this article:

• BR Solar Group BR-M310W
• Conext Insight Home
• DU221RB Safety Disconnect
• BR Solar Group BR-M315W
• Conext XW Conduit Box

Browse all electrical · Browse all circuit breakers · Browse all surge protection

Related Articles

• Electrical Conduit Types: PVC vs. EMT vs. RMC for Solar Installations
• Surge Protection for Solar Systems: SPD Sizing and Installation Guide
• NEC Wire Sizing Guide: Ampacity Charts for Solar and Generator Installations
• Solar Grounding and Bonding Guide: NEC 690.43, 250, and Lightning Protection