2023 NEC Solar Code Guide: Article 690 Updates for Installers
- Sarah Lozanova
- Oct 13
- 8 min read
Table of Contents
Understanding and applying the National Electrical Code (NEC) solar requirements is critical for passing inspections, avoiding redesigns, and keeping projects on schedule. The NEC sets the electrical safety and performance standards that every photovoltaic (PV) system must follow before installers can receive permit approvals or permission to operate (PTO).
The 2023 NEC solar code updates include major revisions to rapid shutdown (690.12), grounding and bonding (690.43), conductor sizing, source connections (705.11), and energy storage commissioning (Article 706). Many AHJs are already enforcing these changes, which means outdated designs or plan sets can lead to failed inspections, costly change orders, and project delays.
By staying aligned with the latest NEC 2023 solar guidelines, installers can streamline permitting, reduce risk, and ensure long-term system safety and compliance.
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What Changed in NEC Article 690
The 2023 NEC solar code introduces major revisions to Article 690, particularly in Sections 690.1 (Scope) and 690.2 (Definitions). These foundational changes reshape how solar installations are classified, documented, and regulated, impacting both design and permitting.
One of the most important updates is the removal and relocation of several PV-related definitions from Article 690 to Article 100. This change standardizes terminology across the entire codebook, ensuring that electrical terms are applied consistently in all NEC sections—not just solar.
For solar designers and installers, this means:
Updating plan sets and documentation to reflect new definition locations
Understanding how Article 690 now references Article 100
Adjusting to revised scope language that clarifies what is (and isn't) covered by Article 690
Preventing confusion during AHJ plan review or field inspection
NEC Solar Code Updates: Conductor Sizing and Overcurrent Protection
The 2023 NEC solar code updates introduce important changes to conductor sizing and overcurrent protection, reflecting the higher voltage and current demands of modern residential, commercial, and utility-scale PV systems. These updates directly impact NEC solar panel installation requirements, making it essential to review ampacity, temperature ratings, insulation, and derating to maintain system safety and performance.
The updated NEC 2023 conductor sizing rules affect how installers calculate voltage drop, grounding methods, and overcurrent protection device (OCPD) selection. Proper conductor sizing is now even more critical to prevent overheating, reduce fire risk, and meet NEC solar compliance standards.
For large-scale PV and battery storage systems, these changes also influence string sizing, wire routing, and equipment layout. By following the latest NEC 2023 solar code requirements, installers can improve efficiency, avoid inspection failures, and design systems that meet both AHJ expectations and long-term performance goals.
NEC 690 PV Labeling & Definition Changes
The 2023 NEC solar code introduces important terminology and definition updates in Article 690 that directly affect design documentation and field installation practices. One of the most significant changes appears in NEC 690.7(A), where the term “PV output circuit” has been replaced with “PV string circuit.”
This update improves clarity in circuit identification and creates consistency across NEC 690 PV labeling, wiring requirements, and compliance documentation. It also aligns terminology with how modern PV systems are designed and interconnected.
For solar installers and designers, this means:
Updating plan sets and line diagrams to use “PV string circuit”
Ensuring labels match NEC 2023 terminology
Avoiding outdated language that can lead to plan review rejection or inspection delays
Improving AHJ communication and approval speed
Accurate and consistent PV string circuit labeling is now essential for meeting NEC solar panel installation requirements, streamlining permitting, and achieving full NEC 2023 solar compliance in both residential and commercial projects.
NEC Solar Rapid Shutdown and Labeling Requirements (Article 690.12)
The 2023 NEC solar code updates to Article 690.12(D) introduce refined rapid shutdown system (RSS) requirements for both residential and commercial PV installations. These changes focus heavily on NEC solar labeling and system identification to improve firefighter safety, simplify inspections, and standardize compliance.
A major emphasis of the NEC 2023 update is clear, consistent, and highly visible rapid shutdown labeling. Labels must now follow more precise wording, placement, and durability requirements to ensure that firefighters, inspectors, and maintenance personnel can quickly identify rapid shutdown capabilities in an emergency.
This means:
Using standardized NEC 690.12-compliant RSS labels
Verifying equipment meets “within array” and “outside array” shutdown requirements
Ensuring labels are weather-resistant and permanently affixed
Updating plan sets and as-builts to match new label language
Preventing inspection delays and redlines due to missing or unclear RSS labels
NEC Grounding and Bonding Requirements for PV Systems (Article 690.43 & 250)
The 2023 NEC solar code introduces critical updates to grounding and bonding requirements in Article 250 and Article 690.43, refining safety and compliance standards for residential, commercial, and utility-scale PV systems. These changes are especially important for larger PV arrays with higher voltage and amperage, where improper grounding can create serious fire and shock hazards.
The latest revisions provide more detailed guidance on how to properly ground and bond PV equipment to prevent electrical faults, improve system reliability, and reduce inspection failures. Article 690.43 now specifies best practices for bonding metal parts, mounting hardware, and equipment enclosures, while ensuring correct conductor sizing and continuity across the entire system.
This means:
Verifying equipment grounding conductors (EGCs) meet new sizing rules
Ensuring effective bonding of all exposed metal parts
Using listed grounding/bonding hardware compatible with racking systems
Avoiding loose or intermittent connections that trigger inspection redlines
Aligning designs with AHJ expectations and NEC inspection requirements
NEC Energy Storage Commissioning Requirements (Article 706.7)
The 2023 NEC solar code introduces new and more rigorous commissioning requirements for energy storage systems (ESS) in Article 706.7(A). These updates significantly change how ESS must be tested, documented, and certified after installation to ensure both safety and performance compliance.
Article 706.7 now outlines specific commissioning procedures that installers must follow, including step-by-step requirements for:
Functional testing
Performance verification
Safety validation
System documentation and recordkeeping
For solar installers and ESS integrators, these updates mean:
You can no longer simply “turn on” a battery system—formal commissioning is required
Documented test results may be requested by the AHJ or utility
Commissioning must confirm the ESS performs within manufacturer specs and NEC safety standards
Improper or incomplete commissioning can delay PTO or fail inspection
NEC 690.11 Arc-Fault Protection Requirements
The 2023 NEC solar code introduces important updates to arc-fault protection in Article 690.11, strengthening the requirements for arc-fault circuit interrupters (AFCIs) in PV systems. These changes are designed to reduce the risk of electrical fires caused by damaged conductors, loose connections, or degraded wiring—issues that are more common as system voltages increase.
The updated NEC 690.11 guidelines now require more robust AFCI technology, improved fault detection capabilities, and clearer criteria for identifying and interrupting dangerous arc conditions. This improves overall system safety, reliability, and NEC solar code compliance.
These NEC 2023 updates mean:
Verifying inverters and combiners include listed AFCI protection that meets new standards
Ensuring proper wiring methods and connection integrity
Updating designs and equipment selections to align with Article 690.11
Preventing fire hazards and inspection failures due to insufficient arc-fault protection
NEC 690.31 Cable Tray Rules for Rooftop PV Systems
The 2023 NEC solar code introduces updated requirements for rooftop cable tray installations in Section 690.31(C)(2). These changes provide clearer guidance for safely routing and supporting PV conductors on rooftops, especially as systems become larger and more complex.
The revised NEC 690.31 cable tray rules help prevent overheating, mechanical damage, and long-term system failures by standardizing how cable trays must be sized, installed, and supported.
Key NEC Solar Code Updates
The updated NEC code for solar installation specifies important factors for cable trays, including:
Sizing: Ensuring adequate capacity to prevent overheating and electrical failures.
Placement: Positioning trays to minimize mechanical damage and exposure to environmental stress.
Support Requirements: Enhancing structural integrity and preventing sagging or movement over time.
NEC 705.11 Source Connection Rules: Splices and Taps
The 2023 NEC solar code introduces new and more stringent requirements for source connections to service equipment in Section 705.11, with a specific focus on splices and taps. These changes directly impact how solar installers must design and install load-side and supply-side connections, making proper materials and methods more critical than ever.
The updated NEC 705.11 guidance clarifies how splices and taps must be implemented to ensure mechanical strength, proper conductor sizing, temperature rating compatibility, and electrical safety. Installers can no longer rely on generic connection methods—listed components and code-approved techniques are now required.
What this update means:
Use listed splice and tap connectors rated for the specific conductor type and ampacity
Follow manufacturer torque specs and installation instructions
Ensure conductor sizing and insulation meet NEC 2023 requirements
Avoid loose or improperly supported connections that can cause overheating or inspection failure
Document source connection details in PV plan sets and as-built drawings for AHJ review
NEC 690.4(F) Guidelines for Floating Solar (Floatovoltaics)
The 2023 NEC solar code introduces new requirements in Article 690.4(F) to address the unique challenges of floating solar installations (floatovoltaics). As more PV systems are deployed on ponds, reservoirs, and other water bodies, the NEC now provides specific safety and design standards to ensure code-compliant installations.
Unlike roof or ground mounts, floating PV systems experience constant environmental movement, which can affect conductor insulation, grounding continuity, mechanical stress, and long-term system durability. Water currents, wave action, and high humidity increase the risk of abrasion, corrosion, and electrical faults.
To mitigate these risks, the 2023 NEC floatovoltaic standards include guidance on:
Conductor protection and insulation
Grounding and bonding in wet environments
Mechanical support and movement allowance
Equipment listing and environmental ratings
Key 2023 NEC Solar Code Changes Installers Must Know
Staying up to date with the 2023 NEC solar code changes is essential for solar installers, electricians, and designers who want to maintain compliance, pass inspections, and avoid costly rework. The latest NEC updates affect nearly every part of the PV system—from terminology and labeling to rapid shutdown, grounding, conductor sizing, energy storage, and source connections.
Compliance and Safety: The 2023 NEC solar updates introduce revised fire protection, grounding, and system disconnect requirements. Following these changes ensures that installations meet the latest safety standards, minimizing electrical hazards and enhancing system reliability.
Technology Advancements: The 2023 NEC reflects advancements in solar technology and system design. Electricians must stay current with these updates to effectively work with new technologies, such as smart inverters and battery storage systems, ensuring optimal performance and compliance.
Regulatory Requirements: Meeting NEC solar code standards is necessary for passing inspections and avoiding legal complications. Keeping up with the latest revisions ensures seamless permitting approvals and maintains professional credibility.
Improved System Performance: The code changes often include provisions that enhance system efficiency and functionality. By applying these updates, electricians can design and install more efficient and reliable solar power systems.
Risk Management: New requirements for fire safety, system monitoring, and grounding help manage and mitigate risks associated with solar installations. Understanding these changes helps electricians prevent potential issues and ensure the long-term safety of installations.
Professional Development: Staying informed on NEC solar updates supports career growth, demonstrating a commitment to best practices and keeping electricians competitive in the evolving solar industry.
How to Stay Compliant with NEC Solar Code for Faster Permitting
The 2023 NEC solar code updates affect nearly every stage of a PV project—from system design and terminology to rapid shutdown, grounding, conductor sizing, source connections, and energy storage commissioning. Staying informed on these changes is essential to maintain compliance, improve safety, and avoid costly redesigns or inspection delays.
Working with a partner who understands NEC 2023 and AHJ requirements can dramatically speed up approvals. GreenLancer provides:
NEC-compliant PV permit plan sets
Engineering reviews and PE stamps
Code-aligned design support
Energy storage and interconnection expertise
A scalable platform built for solar contractors
Whether you're working on residential, commercial, or utility-scale projects, staying compliant with the latest NEC solar standards keeps your jobs moving and protects your bottom line.
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