2023 NEC Solar Code Guide: Article 690 Updates for Installers
- Sarah Lozanova
- 6 days ago
- 28 min read
Updated: 3 days ago
Table of Contents
-- NEC 690.12 Rapid Shutdown Requirements -- Conductor Sizing and Overcurrent Protection -- NEC Grounding and Bonding Requirements
-- NEC 690.11 Arc-Fault Protection Requirements -- NEC 690.31 Cable Management -- Changes That Commonly Affect Permitting -- Code Compliance Checklist
Understanding the NEC solar code, NEC code for solar installation, and solar code requirements is essential if you want projects to move cleanly from design to permit approval, inspection, and interconnection approval. This guide focuses on the 2023 code cycle, with emphasis on NEC Article 690 and related sections that solar installers run into during plan set preparation, equipment selection, labeling, conductor sizing, interconnection, and field installation.
When your team applies the right code language and design assumptions early, you can reduce redlines, avoid costly change orders, and build safer PV systems that are easier for jurisdictions and utilities to approve.
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Why the NEC Solar Code Matters for Installers
For solar installers, the NEC solar code sets the technical rules that shape a project long before the inspector arrives. It affects how systems are documented, what equipment can be used, how conductors are sized, how labels are written, and how interconnections are shown in the permit set. Staying current with solar codes and standards helps your team avoid preventable revisions and keep projects moving toward permit approval, inspection, and PTO.
The 2023 NEC cycle deserves close attention because it changes several areas that show up often in solar work, including Article 690 terminology, rapid shutdown details, labeling requirements, and source connection documentation. If your team is still using older assumptions or outdated templates, those gaps can surface during plan review or in the field.
Where the NEC Code for Solar Installation Shows Up Most
The NEC code for solar installation affects day-to-day work in several places:
Plan Sets And One-Line Diagrams - Notes, code references, and circuit naming should match the adopted code cycle.
Equipment Selection - Inverters, disconnects, rapid shutdown equipment, conductors, OCPDs, and connection hardware all need to support the intended compliance path.
Labeling And Placards - Label schedules need to match the current NEC language and the actual installed equipment.
Conductor Sizing And Protection - Ampacity, correction factors, and OCPD coordination have to line up with the design assumptions shown on the plans.
Interconnection And Service Equipment Decisions - The code affects whether a system can use a standard load-side connection or needs a source connection approach.
Field Installation Details - Grounding, bonding, wiring methods, and shutdown labeling all need to match the approved design.
Outdated Assumptions Can Cause Redlines and Rework
A common source of delay is not a major design error. It is using legacy templates, outdated terminology, or old code assumptions that no longer match the adopted NEC cycle. A permit set can look complete and still trigger avoidable review comments if the notes, labels, or connection details are based on an older standard.
Typical examples include:
Using Old Article 690 Terminology in notes, one-lines, or equipment callouts
Showing Rapid Shutdown Details That Do Not Match the equipment method or current label language
Reusing Old Placard Schedules without checking the 2023 labeling requirements
Leaving Source Connection Notes Incomplete for projects that need the current 705.11 detail
Carrying Over Conductor Sizing Notes that do not match the actual module, inverter, or OCPD configuration
Using Generic Templates For Storage Or Interconnection that do not reflect the current project scope
The result is usually familiar:
Permit Redlines
Delayed Approvals
Last-Minute Engineering Revisions
Material Changes After Submittal
Failed Inspections
Extra Labor And Repeat Site Visits
For installers, this is why NEC compliance is not just an inspection issue. It is a template, design, and operations issue. When your plan set, equipment selections, and field details all reflect the current code cycle, projects move with fewer surprises.
Before You Apply This Guide, Check Which NEC Edition Your AHJ Uses
Before you apply any NEC solar code update to a live project, confirm which code cycle the local Authority Having Jurisdiction is enforcing. NEC adoption is not uniform across the U.S. Some states and local jurisdictions are on NEC 2023, others are still on NEC 2020, and some have local amendments that change how the NEC code for solar installation is reviewed in practice. That matters because your plan notes, one-line diagram language, rapid shutdown details, source connection method, and labeling package all need to match the code cycle the AHJ is actually using.
For installers, this is more than a paperwork issue. A design that is technically correct under NEC 2023 can still draw redlines if the jurisdiction is reviewing under NEC 2020 language, especially in areas like NEC Article 690 terminology, rapid shutdown exceptions, and newer source connection details. The cleanest approach is to verify the adopted NEC edition early, then align your permit package, field labels, and installation details to that edition from the start.
Why NEC Adoption Matters for Solar Permitting
Code adoption affects what the AHJ expects to see in the permit package and what the inspector expects to see in the field. Even when your team is familiar with the latest solar code, the reviewer may be checking against an earlier adopted edition.
That can change whether updated terminology is acceptable, whether a rapid shutdown exception applies, or how source connections and related service equipment details are evaluated. NFPA’s enforcement maps exist for this exact reason: the adopted NEC edition varies by jurisdiction.
From a permitting standpoint, the safest workflow is to verify the code cycle before finalizing:
one-line and three-line diagrams
plan notes
placard and labeling schedules
rapid shutdown callouts
source connection details
storage and interconnection notes
That extra check can prevent unnecessary back-and-forth with plan reviewers and reduce the chance that a field install no longer matches the approved drawing set.
What Changed in NEC Article 690
For readers searching for NEC Article 690, Article 690 NEC, or NEC 690, the main takeaway is that the 2023 cycle did not rewrite the entire article from scratch, but it did make several important updates that affect PV design, documentation, and inspection. The biggest high-level changes include a refined scope in 690.1, movement of Article 690 definitions into Article 100, added listing language in 690.4(B), clarified rapid shutdown language in 690.12, and other targeted revisions that support newer PV architectures and cleaner code organization.
For installers, these updates matter because they affect how you describe the system, how you document it in the plan set, and how you coordinate with AHJs during review. The 2023 NEC also continues to reflect the reality that PV systems now intersect more often with storage, interactive power production, nontraditional mounting structures, and more complex equipment configurations.
NEC Article 690 Scope and Definition Updates
One of the most important structural changes in NEC Article 690 is that the definitions formerly located in 690.2 were moved to Article 100. That means installers, designers, and reviewers now need to look outside Article 690 for defined PV terms. This change helps standardize terminology across the NEC, but it also means older templates and internal design references may be out of sync if they still treat 690.2 as the main definition section.
The scope language in 690.1 was also refined. IAEI’s 2025 overview explains that Article 690 more clearly covers conventional PV systems, including stand-alone, hybrid, and utility-interactive systems, while Article 691 remains reserved for utility-scale PV power stations. For installers, that scope clarification matters because it helps define when standard PV jobs should remain under Article 690 rather than being treated as something outside the normal residential or commercial rooftop code path.
There is also a practical documentation impact from these scope and definition updates. If your company’s standard notes, symbols, callouts, or training materials still use legacy wording or outdated section references, they should be updated. Reviewers may not always reject a plan set over terminology alone, but inconsistent code language can slow down review and create confusion during inspection.
What These NEC 690 Changes Mean for Plan Sets
The 2023 NEC solar code changes should show up clearly in your design package. At a minimum, installers and design teams should review their one-lines, equipment schedules, general notes, labeling sheets, and standard code references to make sure they align with the adopted edition and current Article 690 structure. This is especially important if your team reuses legacy templates across multiple AHJs.
Plan set items to review include:
Defined terms and circuit naming conventions
References to Article 690 versus Article 100 definitions
Rapid shutdown notes and equipment descriptions
Labeling schedules and placard language
Source connection notes where Article 705 is involved
Listing references for PV equipment and related components
Those updates are not just editorial. In practice, they affect how clearly the AHJ can verify compliance, how smoothly the field crew can match the approved drawings, and how easily inspectors can confirm that the built system matches the permitted design.
A good rule for installers is to treat NEC 690 updates as a template-management issue as much as a field issue. If your notes, one-line libraries, and labeling standards are current, you reduce the chance of carrying old assumptions into new projects. That helps with cleaner submittals, fewer clarifications during review, and better consistency between design, permitting, and installation.
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For installers, NEC 690 PV labeling is not a minor paperwork detail. In the 2023 cycle, several labeling and terminology items were reorganized or moved, which means older plan set templates can fall out of sync even when the electrical design itself is sound.
The biggest changes affecting submittals and field labels are the move of Article 690 definitions into Article 100, the addition of 690.7(D) for DC voltage marking, the reorganization of rapid shutdown labeling into 690.12(D), and the consolidation of power source identification requirements into 705.10.
PV Output Circuit vs. PV String Circuit
One of the most important terminology shifts in the 2023 NEC solar code is that PV String Circuit is now a defined term in Article 100, while the older concept of a PV output circuit was absorbed into the broader updated definition of PV source circuit. Mayfield notes that the definition of PV source circuit now encompasses what was previously defined as PV output circuits, and IAEI notes that 690.8(D) is now titled Multiple PV String Circuits, while 690.9(C) is now called PV System DC Circuits.
That matters in practice because your one-line diagram, conductor callouts, circuit schedules, and field labeling should use current code language. If a plan set still mixes legacy phrases like “PV output circuit” with newer NEC 2023 references, the reviewer has to reconcile two naming systems for the same conductors. Even if the AHJ does not reject the set outright, inconsistent terminology slows review and creates confusion between the drawings, placards, and installation crew.
Labels Installers Should Review Before Submittal
Before submitting a permit package, review the following 2023 NEC solar labeling requirements carefully:
Maximum DC voltage marking - Under 690.7(D), the installer must provide a permanent, readily visible label showing the highest maximum DC voltage in the PV system. The label can be placed at the DC PV system disconnecting means, the PV system electronic power conversion equipment, or distribution equipment associated with the PV system.
DC conductor polarity identification - Under the reorganized 690.31(B)(2) language, PV system DC circuit conductors must be identified at all termination, connection, and splice points by color coding, marking tape, tagging, or another approved means. If polarity is identified by a permanent marking method rather than conductor color, the code calls for durable markings such as labeling, sleeving, or shrink tubing. Positive conductors must be marked with +, POSITIVE, or POS. Negative conductors must be marked with −, NEGATIVE, or NEG.
Rapid shutdown building label - In NEC 2023, the former 690.56(C) building rapid shutdown marking was moved into 690.12(D). The building label must be permanent, located at each service equipment location connected to the PV system or at an approved, readily visible location, indicate the location of the rapid shutdown initiation device, include a simple roof diagram, and include the wording:
SOLAR PV SYSTEM IS EQUIPPED WITH RAPID SHUTDOWNTURN RAPID SHUTDOWN SWITCH TO THE “OFF” POSITION TO SHUT DOWN PV SYSTEM AND REDUCE SHOCK HAZARD IN ARRAY
The title text must be capitalized and at least 3/8 inch high, and all text must be legible and contrast with the background.
Rapid shutdown switch label - The switch label requirement was also moved into 690.12(D)(2). The label must be located on or within 1 m 3 ft of the switch and use the wording:
RAPID SHUTDOWN SWITCH FOR SOLAR PV SYSTEM This label remains reflective, with all capital letters at least 3/8 inch high in white on a red background.
Power source directory or plaque - NEC 2023 705.10 now serves as the main location for power source identification requirements referenced by other sections. At each service equipment location, or another approved readily visible location, the plaque, label, or directory must identify the location of each power source disconnect, include the emergency telephone numbers of any off-site entities servicing the power source systems, and include the wording CAUTION: MULTIPLE SOURCES OF POWER.
Common Labeling Mistakes That Trigger Redlines
The most common labeling-related redlines are usually not exotic code issues. They are templates and coordination failures. Watch for these problems:
Using old references to 690.56(C) instead of the current 690.12(D) rapid shutdown building marking section
Leaving legacy terminology, such as PV output circuit, in notes, diagrams, or placards when the rest of the plan set uses NEC 2023 language
Omitting the 690.7(D) maximum DC voltage label from the disconnect, inverter, or associated distribution equipment
Providing a 705.10 directory that does not include disconnect locations, the required CAUTION: MULTIPLE SOURCES OF POWER wording, or off-site emergency contact numbers
Showing one rapid shutdown method on the one-line, but using field labels that imply a different method or a different initiation device
Failing to show permanent polarity identification for DC conductors at terminations and splice points where required by 690.31(B)(2)
NEC 690.12 Rapid Shutdown Requirements for Solar Installers
NEC 690.12 remains one of the most important and most misunderstood parts of the NEC solar panel requirements for rooftop PV. In the 2023 NEC, the core firefighter-safety purpose did not change, but the code added useful clarification for detached non-enclosed structures, clarified certain exterior conductor situations, and moved rapid shutdown marking requirements into 690.12(D) so the rules and labels live in one place.
What Changed in Rapid Shutdown Requirements
The biggest practical 2023 change is Exception No. 2 to 690.12, which now makes clear that non-enclosed detached structures do not require rapid shutdown. Mayfield specifically points to canopies, carports, and trellises as the kinds of structures that drove this clarification, and IAEI notes that 690.12(A) also gained an exception for arrays not attached to buildings when the circuits terminate on the exterior of a building and are installed in accordance with 230.6.
Inside the array boundary, the basic compliance paths remain familiar, but the 2023 NEC refined how they are presented. IAEI explains that 690.12(B)(2)(3) was removed because it was effectively absorbed into the UL 3741 pathway, while 690.12(B)(2)(2) still requires the applicable conductors inside the array boundary to be limited to not more than 80 V within 30 seconds of rapid shutdown initiation unless the installation is using the listed PVHCS compliance path. IAEI also notes that 690.12(B)(2)(1) in 2023 continues the PVHCS approach, tied to listing or field labeling and installation in accordance with the listing instructions.
Residential Rooftop PV vs. Detached Structures
For a typical residential rooftop PV system on a dwelling, installers should still assume 690.12 rapid shutdown applies and should clearly document the chosen compliance method. The purpose remains firefighter safety on occupied buildings where responders may need rooftop access. For one- and two-family dwellings, the initiation device must be at a readily accessible location outside the building, which is a key field detail that plan sets and installers need to match.
Detached non-enclosed structures are different. NEC 2023 now explicitly excludes non-enclosed detached structures, such as many carports, canopies, and trellises, from the rapid shutdown requirement. Mayfield explains that this clarification was added because rooftop firefighting and rescue operations are not expected in the same way on those open structures. Just do not over-apply that exemption. A roof-mounted array on an occupied building is still a different analysis from an open detached canopy.
Rapid Shutdown Labels, Initiation Devices, and Inspection Issues
A large share of NEC 690.12 problems are documentation and labeling issues, not inverter hardware problems. In NEC 2023, the building rapid shutdown label is now in 690.12(D), and the dedicated rapid shutdown switch label is in 690.12(D)(2). The building label must identify the initiation device location and include the required wording and roof diagram. The switch label must be on or within 3 ft of the switch and must remain reflective, white on red, and in all caps.
Installers also need to be precise about the initiation method. Under the current 690.12(C) framework, the initiation device is what puts the PV system into rapid shutdown mode, and the off position must indicate that the rapid shutdown function has been initiated. For one- and two-family dwellings, that initiation device must be outside and readily accessible. If the design relies on a PVHCS or another listed method that requires initiation to transition to a controlled state, the rapid shutdown initiation device must perform that function.
What to Verify Before Submitting a Permit Package
Before sending a permit package to the AHJ, verify all of the following:
The plan set clearly states which 690.12(B)(2) compliance path is being used
If the design relies on UL 3741 / PVHCS, the plans identify the specific listed equipment and match the certificate or manufacturer documentation
If the design relies on the 80 V within 30 seconds path, the plans call out the specific rapid shutdown equipment or calculation basis
The one-line, roof plan, and notes show the initiation device location and the correct rapid shutdown operation
The 690.12(D) building label and the 690.12(D)(2) switch label are both shown correctly in the label schedule
The field installation will match the approved plans, especially for the exact equipment named in the rapid shutdown method
NEC Solar Panel Requirements for Conductor Sizing and Overcurrent Protection
For installers, the NEC solar panel requirements around conductor sizing and OCPD selection are where design assumptions quickly become plan review comments. In NEC 2023, 690.8 and 690.9 remain the core sections for circuit current, conductor ampacity, and overcurrent protection, with some organizational cleanup such as the renaming of 690.8(D) to Multiple PV String Circuits and 690.9(C) to PV System DC Circuits. The underlying design work still depends on correct current calculations, ampacity correction and adjustment, and coordination between conductor ratings, module data, inverter data, and protective devices.
Conductor Sizing Basics Installers Cannot Skip
Under 690.8(A)(1)(a)(1), if the PV system is rated below 100 kW, the maximum PV system circuit current is 125 percent of the sum of the short-circuit current ratings of the PV modules connected in parallel. NEC also allows a different path in 690.8(A)(2) when a circuit is protected by an OCPD that does not exceed the conductor ampacity. In that case, the maximum current can be the rated input current of the inverter to which the circuit is connected.
For conductor sizing itself, 690.8(B) says the conductor ampacity must be at least the larger of two values:
125 percent of the current determined under 690.8(A)
100 percent of the current determined under 690.8(A) after ampacity correction and adjustment under the applicable Article 310 tables
For parallel-connected PV string circuits with overcurrent protection, 690.8(D) is especially important. The conductor ampacity must be at least the sum of:
The rating of the OCPD, and
The calculated current from the other parallel-connected PV string circuits protected by OCPD.
In practice, that means installers cannot size PV conductors by module nameplate intuition alone. You need to know the applicable short-circuit current basis, whether the inverter input current path is being used, what conductor correction and adjustment factors apply, and whether the conductors are part of a parallel string configuration that changes the required ampacity. As a design matter, those same choices also affect voltage-drop performance, inverter operating margin, and equipment layout, even though 690.8 itself is primarily an ampacity section.
Overcurrent Protection and Equipment Coordination
690.9(A) states that PV system DC circuits, inverter output conductors, and associated equipment must be protected against overcurrent. But NEC also provides a narrow path where OCPDs are not required. Under 690.9(A)(1), OCPDs are not required if:
The PV system DC circuit conductors have ampacity at least equal to the current determined under 690.8(B), and
The currents from all PV sources do not exceed the OCPD rating specified by the manufacturer for the PV module or electronic power converters.
OCPDs are required when a PV circuit conductor is connected at one end to a current-limited supply and also connected to sources that can deliver current greater than the conductor ampacity at the point of connection to the higher-current source, per 690.9(A)(2). For DC source circuits, 690.9(B) requires OCPDs to be listed for PV systems. NEC also allows a single OCPD on one of the two circuit conductors for protecting PV modules and DC-to-DC converter circuit conductors under 690.9(C), as long as polarity is handled consistently across the PV system.
The practical takeaway is that OCPD selection is not just a fuse size exercise. It has to coordinate with:
The conductor ampacity you actually calculated is under 690.8
The module or inverter manufacturer’s OCPD limits
Whether the conductors are in a parallel string arrangement
Whether the assembly is listed for 100 percent continuous operation, which can affect the allowable sizing path for both conductors and OCPDs
Why Conductor and OCPD Issues Show Up in Redlines
Conductor and overcurrent problems show up in solar plan review because they expose inconsistencies fast. Common redline items include:
Conductor sizes that do not reconcile with the 690.8(A) current basis shown on the one-line diagram
Ampacity notes that do not show whether corrections and adjustments were applied
OCPD values that exceed module or inverter manufacturer limits
Parallel string circuits that do not account for the 690.8(D) added ampacity requirement
The generic plan notes mention 125 percent sizing without showing the actual calculation path
DC source circuit fuses or breakers that are not identified as listed for PV systems, where required by 690.9(B)
For installers, this is where strong plan-set discipline pays off. If the conductor calculations, protective device ratings, and equipment datasheet limits all tell the same story, the AHJ can verify compliance quickly. If those pieces do not line up, the result is usually a correction notice, a redesign, or a field change order after procurement has already started.
NEC Grounding and Bonding Requirements for PV Systems
For installers, the NEC grounding and bonding requirements for PV systems are where the code moves from theory into hardware. This is the part of the solar codes and standards discussion that affects racking, module frames, metal raceways, equipment enclosures, EGC routing, and the fault-current path that has to work when something goes wrong. In NEC 2023, the grounding and bonding portion of Article 690 was refined for clarity rather than completely rewritten, but the practical requirements still matter at both plan review and inspection.
NEC 690.43 and Article 250 Basics for Solar Projects
NEC 690.43 is the PV-specific grounding and bonding section, but it does not work by itself. It points installers back to Article 250, which supplies the general bonding methods, continuity requirements, and grounding rules used across electrical installations. Mike Holt’s summary of 690.43 makes the relationship clear: metal parts of PV equipment must connect to the equipment grounding conductor just like any other electrical installation, and PV installers need to know how mounting structures are bonded, where EGCs are routed, and when Article 250 bonding rules become critical.
From a design and field standpoint, think of the code in two layers:
Article 690 tells you which PV system parts must be bonded and grounded.
Article 250 tells you how bonding and grounding must be achieved so the path is electrically continuous and capable of carrying fault current safely.
IAEI’s 2023 NEC summary notes that 690.43(A) was only slightly shortened and given an informational note, while 690.43(C) was retitled and clarified. That means the installer takeaway is not “learn an entirely new grounding scheme.” It is “make sure your existing PV grounding and bonding details are correct, current, and documented clearly.”
Grounding and Bonding Details Installers Should Double-Check
In the field, the grounding and bonding details that matter most are usually the ones hidden inside otherwise routine installation work. Based on 690.43 guidance and Article 250 bonding rules, these are the items worth checking closely:
Listed Bonding Hardware - Devices used to secure and bond PV module frames to metal support structures and adjacent PV modules must be listed, labeled, and identified for bonding. If the attachment hardware is not identified for bonding, do not assume the mechanical attachment also provides an acceptable bonding path.
Metal Support Structure Continuity - Metallic support structures that are listed, labeled, and identified for bonding and grounding metal PV parts can be used to bond PV equipment to the support structure. But if the support structure is used as an equipment grounding conductor, separate metallic sections need to be identified and bonding jumpers installed between them unless the structure itself is identified for equipment bonding purposes.
Equipment Grounding Conductors - The metallic support structure still has to be connected to the PV circuit equipment grounding conductor as required by 690.43. In other words, relying on rail-to-rail contact or module clamps alone is not enough unless the complete bonding path is part of a listed method.
Metal Raceways And Enclosures - Where service-related PV connections are involved, Article 250 bonding rules become especially important. Article 250.92(B) requires bonding jumpers around impaired connections, such as reducing washers and oversized, concentric, or eccentric knockouts. Standard locknuts or bushings can make the mechanical connection, but they cannot be the only bonding means where 250.92(B) applies.
Paint, Coatings, And Surface Conditions - Nonconductive coatings such as paint can interrupt the fault-current path. Article 250 guidance, summarized by Mike Holt, notes that coatings must be removed where necessary, unless the fitting is designed so that coating removal is unnecessary. That matters on rails, enclosures, and any connection point where continuity is assumed.
Common Grounding and Bonding Inspection Issues
The grounding and bonding problems that trigger inspection failures are usually not exotic code questions. They are continuity and listing problems. Common examples include:
Using Unlisted Module Clamps Or Hardware where the installer assumes the clamp also provides the bonding path
Failing To Bond Separate Rail Sections when the racking system is being relied on as part of the equipment grounding path
Leaving Paint Or Coatings Intact at a connection point that is supposed to carry fault current
Using Standard Locknuts Alone where Article 250 requires a listed bonding method around concentric or eccentric knockouts
Omitting The EGC Path In Drawings so the plan set does not clearly show how module frames, rails, enclosures, and raceways are bonded together
Mismatch Between The Approved Plan And Installed Hardware, where the drawings assume a listed bonding system, but field substitutions were made without confirming equivalent listing and bonding performance
For installer audiences, the simplest message is this: NEC requirements for solar photovoltaic systems are not satisfied by a general note saying “ground per code.” The plan set and the field installation both need to show a continuous, listed, code-compliant bonding path from exposed metal PV parts back to the grounding system.
NEC 705.11 Source Connections: What Solar Installers Need to Know
NEC 705.11 is the section installers run into when a PV system cannot use a straightforward load-side breaker connection and the interconnection has to happen on the service side. In NEC 2023, this section was significantly revised and expanded, with clearer organization for service connections, conductors, splices or taps, service disconnecting means, bonding and grounding, and overcurrent protection. For installers, this is one of the most practical sections in the NEC code for solar installation because it shapes how larger PV systems tie into existing service equipment.
When NEC 705.11 Becomes Important on Solar Jobs
NEC 705.11 source connections matter when the existing service equipment limits what you can do on the load side. IAEI notes that in many residential and commercial installations, the desired PV system size exceeds the rating of the existing service and main load center, or the wiring is not readily accessible for a conventional load-side interconnection. In those cases, the installer may need to consider a source connection to the service instead.
This section becomes especially relevant when:
The Main Panel Cannot Accept More Backfeed
The 120 Percent Busbar Path Is Not Available Or Not Cost-Effective
The Desired PV Size Is Larger Than The Existing Load-Side Equipment Can Support
The Service Layout Makes A Load-Side Connection Impractical
The Project Includes New Or Modified Service Equipment As Part Of The Interconnection Strategy
IAEI also points out that 705.11(A) allows three broad service-connection methods: adding a new service under 230.2(A), connecting to the supply side of the service disconnecting means under 230.82(6), or adding an additional set of service-entrance conductors under 230.40 Exception No. 5. That is why 705.11 is really an interconnection and service-equipment section, not just a generic wiring rule.
Splices, Taps, and Listed Connection Methods
One of the most important practical points in NEC 705.11 is that supply-side or service-side PV connections are not “make it fit” work. The connectors, splices, taps, and enclosure modifications all have to be properly listed and appropriate for the exact service-side application.
The 2023 NEC revisions put more structure around this. IAEI notes that 705.11(C), now titled Connections, was significantly expanded and now includes subparagraphs for Splices or Taps, Existing Equipment, and Utility-Controlled Equipment. Mayfield also notes that the code-making panel added new requirements specifically around how splices or taps are made to service conductors.
Installers should pay attention to these details:
Listed Connectors - Service-entrance spliced and tapped conductors, such as pressure connectors or distribution blocks, must be listed for the application. Greentech’s NEC 2023 summary notes that these devices need to be suitable for use on the line side of service equipment.
110.14 Compliance - Earlier NEC commentary, summarized by Solar Builder and Mayfield, emphasized that the connection must be made using listed connectors as described in 110.14, and that ratings and installation suitability matter.
Conductor Compatibility - The connection hardware has to match the conductor type and installation conditions. That includes copper versus aluminum compatibility, conductor range, temperature rating, and whether the connector is identified for service-side use. Using a generic connector that fits physically is not enough.
Existing Equipment Modifications - NEC 705.11 allows use of existing equipment only if modifications are made in accordance with manufacturer instructions, or the modified equipment is evaluated for the application and field labeled where required.
Utility-Controlled Equipment - If the connection touches meter sockets or other equipment under exclusive utility control, utility approval is required. Installers should not assume NEC compliance alone is enough.
Source Connection Details That Should Appear in the Plan Set
Because NEC 705.11 involves service conductors and service equipment, the plan set needs to be much more explicit than it would be for a basic load-side breaker interconnection. The AHJ and the field crew should be able to see exactly how the connection will be made and exactly what hardware and disconnecting means will be used.
At a minimum, the plan set should clearly show:
The 705.11 Connection Method - Identify whether the project is using a supply-side connection to the service disconnecting means, a new service, or an additional set of service-entrance conductors.
Conductor Sizes And Materials - IAEI notes that 705.11(B)(2) requires conductors connected to the power production source output disconnecting means to be sized in accordance with 705.28 and to be no smaller than 6 AWG copper or 4 AWG aluminum or copper-clad aluminum.
Connection Hardware Or Tap Method - The drawings should identify the listed splice, tap, or connection method being used, especially where service conductors are modified or landed in existing equipment.
Service Disconnecting Means - NEC 2023 added 705.11(D) to require a disconnecting means in accordance with Parts VI through VII of Article 230 for disconnecting all ungrounded conductors of the power production source from conductors of other systems. This should be shown clearly in the one-line and equipment schedule.
Bonding And Grounding Method - Under 705.11(E), all metal enclosures, metal wiring methods, and metal parts associated with the service connected to a power production source must be bonded in accordance with Parts II through V and VIII of Article 250. If the connection passes through service raceways or concentric knockouts, show the bonding method instead of assuming it.
Overcurrent Protection Strategy - NEC 2023 moved much of the overcurrent detail to 705.30 and Article 230 references. If the design depends on conductor length limits, disconnect location, or a specific OCPD arrangement, document that clearly so the installer and reviewer are working from the same assumptions. Mayfield notes that NEC 2023 changed and clarified this part of the conductor-length and OCPD framework compared with NEC 2020.
NEC Article 706 and Energy Storage System Requirements
For solar-plus-storage installers, NEC Article 706 is the main code section for permanently installed energy storage systems that are interactive with PV or other power production sources. In NEC 2023, Article 706 applies to ESS with a capacity greater than 1 kWh and includes updates around scope, disconnecting means, emergency shutdown functionality, and commissioning.
What Article 706 Means for Solar-Plus-Storage Projects
In practical terms, Article 706 tells installers how the battery side of a solar-plus-storage system must be isolated, labeled, and documented. It matters for AC-coupled and DC-coupled systems because the ESS is treated as its own code-regulated power source, not just an accessory to the PV array. Article 706 generally applies to modern cycling battery systems, while older stationary standby battery systems may instead fall under Article 480.
Commissioning and Documentation Requirements
One of the more important energy storage system requirements in NEC 2023 is 706.7. For systems other than one- and two-family dwellings, the ESS must be commissioned upon installation. NEC 2023 also requires maintenance records for those non-dwelling systems. For installers, that means larger battery projects should have a documented closeout process that covers functional verification, operating controls, safety systems, and records of repairs or replacements.
Residential vs. Larger Commercial ESS Considerations
Residential battery jobs are not treated exactly the same as larger commercial ESS projects. The commissioning requirement in 706.7(A) does not apply to one- and two-family dwellings, while larger non-dwelling systems have a more formal commissioning and maintenance expectation. At the same time, NEC 2023 adds an emergency shutdown function for ESS in one- and two-family dwellings, with the initiation device in a readily accessible location outside the building. That difference is important when moving between residential backup systems and larger commercial solar-plus-storage work.
NEC 690.11 Arc-Fault Protection Requirements
For installers reviewing NEC 690.11, the main point is straightforward: arc-fault protection is a PV fire-safety requirement intended to detect dangerous DC arcing before it can ignite combustible materials or damage equipment. This section is especially relevant on building-mounted PV systems where damaged conductors, poor terminations, or degraded connections can create persistent arc conditions.
Where NEC 690.11 Applies in Solar Installations
NEC 690.11 requires listed DC arc-fault protection or equivalent equipment for PV systems operating at 80 V DC or greater between any two conductors. The requirement does not apply to PV arrays that are not mounted on or in buildings, or to DC output circuits installed in metallic raceways or metallic enclosures. For rooftop installers, this means arc-fault protection is usually part of the compliance path on building-mounted systems, especially residential rooftops.
Equipment and Wiring Considerations
From an installation standpoint, arc-fault protection requirements tie directly to inverter selection, listed equipment, and wiring quality. IAEI notes that arc-fault protection for PV systems is tied not only to NEC 690.11 but also to product listing standards such as UL 1741 and UL 1699B. In practice, installers should verify that the inverter or equivalent equipment includes the required protection, and they should pay close attention to conductor damage risks, connector integrity, and termination quality because sloppy wiring work can create the very fault conditions the protection is designed to detect.
NEC 690.31 Cable Management and Rooftop Wiring Rules
NEC 690.31 matters because a lot of solar inspection issues come down to how conductors are routed, supported, grouped, and protected on rooftops and inside buildings. NEC 2023 reorganized and expanded this section, especially around conductor identification, cable tray use, and DC wiring methods on or in buildings. For installers, this is where code compliance overlaps directly with field workmanship.
What NEC 690.31 Means for Rooftop Solar Wiring
For rooftop PV systems, NEC 690.31 covers more than just “use the right wire.” It affects:
Conductor Identification
Grouping Of AC And DC Conductors
Support And Securement
Cable Tray Use
Metal Raceway Requirements For DC Circuits In Buildings
For example, PV system DC conductors must be permanently identified for polarity at terminations, connection points, and splices, and DC and AC conductors in the same enclosure or wireway must be grouped separately at intervals not exceeding 6 ft unless the routing already makes the grouping obvious.
Cable Tray and Conductor Support Considerations
NEC 2023 expanded 690.31(C)(2) to provide more detail for single-conductor PV wires smaller than 1/0 AWG installed in cable trays. Mike Holt’s 2023 NEC summary notes that in uncovered cable trays, ampacity and adjustment rules apply differently based on conductor size and tray type, and that where smaller single conductors are installed in ladder or ventilated trough trays, they generally need to be in a single layer unless bound together as circuit pairs.
The sum of conductor diameters also cannot exceed the cable tray width. Mike Holt also notes that exposed single-conductor cables 8 AWG or smaller must be supported and secured at intervals not exceeding 24 inches using fittings listed for outdoor support.
2023 NEC Solar Code Changes That Commonly Affect Permitting
For installers, the most important 2023 NEC solar code changes are not always the ones with the biggest code rewrite. They are the ones who change what has to appear in the plan set, on the label schedule, and in the field. In NEC 2023, that usually means updated terminology, rapid shutdown labeling, cable and conductor details, source connection documentation, and cleaner coordination between Articles 690, 705, and 706.
Plan Set Updates Installers Should Make Now
At a minimum, current solar permit templates should be reviewed for:
Article 690 Terminology
Rapid Shutdown Notes And Labels
Maximum DC Voltage Labeling
Conductor Identification And Grouping Notes
Source Connection Details Under 705.11
Grounding And Bonding Callouts
ESS Notes For Solar-Plus-Storage Projects
The goal is to make sure the one-line, roof plan, notes, and label schedule all reflect the same code cycle and the same equipment method.
AHJ Redlines Installers Can Avoid
The most common redlines tied to NEC 2023 updates usually involve:
Old Article References
Outdated Rapid Shutdown Placards
Mismatch Between One-Line Notes And Field Labels
Weak 705.11 Source Connection Detail
Incomplete Grounding And Bonding Notes
Unclear Conductor Sizing Or Cable Routing Assumptions
Battery Documentation Gaps On Storage Projects
These are usually preventable if the design package is updated before submittal instead of relying on legacy templates.
Solar Code Compliance Checklist for Installers
Before Design
Confirm The AHJ Code Cycle
Verify Equipment Listing And Compatibility
Check Service Equipment Constraints
Identify Whether The Project Includes ESS, Supply-Side Connection, Or Special Rooftop Wiring Conditions
Those early decisions affect whether the project should be designed around standard Article 690 assumptions or needs additional 705 or 706 detail.
Before Permit Submission
Review One-Line Terminology
Verify Label Schedules
Check Rapid Shutdown Method And Initiation Device
Confirm Conductor Sizing And OCPD Coordination
Document 705.11 Source Connection Details If Used
Update Grounding And Bonding Notes
Include ESS Disconnect Or Shutdown Information Where Required
This is where most avoidable permitting issues are caught.
Before Inspection
Verify Installed Labels Match The Approved Plan Set
Check Torque, Terminations, And Connector Integrity
Confirm Grounding And Bonding Continuity
Verify Rooftop Cable Support And Routing
Confirm ESS Disconnecting Means Or Shutdown Devices
Make Sure Field Installation Matches The Approved Equipment Method
That final consistency check helps prevent failed inspections caused by late substitutions or field improvisation.
How NEC-Compliant Design Support Can Help Solar Installers
For many installers, the hardest part of NEC solar code compliance is not understanding one section in isolation. It is keeping permitting, engineering, labeling, and field execution aligned across different AHJs and project types. That gets harder when the project includes storage, nonstandard service equipment, or a fast-moving install schedule. The cost of a code miss is often not just a correction notice. It is a truck roll, a delayed inspection, or a change order after materials are already committed.
When It Makes Sense to Get Engineering or Permitting Help
It often makes sense to bring in engineering or permitting support when a project involves:
Complex Interconnections
NEC 705.11 Source Connections
Solar-Plus-Storage Systems
AHJ-Specific Redlines
Large Backlogs Or Fast Growth
Internal Teams Reusing Outdated Templates
These are the projects where permit-ready documentation can save more than it costs.
How GreenLancer Supports NEC-Compliant Solar Projects
GreenLancer helps solar installers with:
Solar-Plus-Storage Documentation
That can help your team reduce redlines, speed up approvals, and keep design assumptions aligned with the actual field installation.
Final Thoughts on NEC Solar Code Compliance
The NEC solar code is more than a rulebook for plan reviewers. For installers, it is part of the workflow that determines how fast a project moves, how often it gets redlined, and how confidently the crew can install to the approved drawings. When NEC Article 690, Article 705, and Article 706 are treated as part of the design and operations process instead of a last-minute compliance check, jobs tend to move with fewer surprises, fewer revisions, and better inspection outcomes.
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.
Complete the form below to learn how GreenLancer can help you design, engineer, and permit NEC-compliant solar projects with confidence.
FAQs on 2023 NEC Solar Code
Does NEC 2023 apply to every solar project?
No. The NEC solar code that applies to a project depends on the edition adopted by the local AHJ, and some jurisdictions also enforce local amendments. Installers should confirm the adopted code cycle before finalizing plan sets, label schedules, or field details.
What are the most important NEC Article 690 changes for installers in the 2023 cycle?
At a high level, NEC Article 690 moved PV definitions to Article 100, clarified rapid shutdown requirements in 690.12, expanded parts of 690.31 for wiring methods and cable trays, and updated related labeling and identification references. For installers, the practical impact is on plan-set language, equipment documentation, and inspection readiness.
Is “PV output circuit” still the right term in NEC 2023?
Not usually. In NEC 2023, PV String Circuit is now a defined term in Article 100, and the older PV output circuit concept was folded into updated PV circuit terminology, so permit sets should be reviewed for outdated labels and notes.
What labels are most often missed under the 2023 NEC solar labeling requirements?
The most common misses in 2023 NEC solar labeling requirements are the 690.7(D) maximum DC voltage marking, the 690.12(D) rapid shutdown building and switch labels, the 705.10 multiple power source directory, and permanent DC polarity identification required by 690.31(B)(2). These are small details, but they are frequent sources of permit comments and inspection corrections.
Do detached carports, canopies, and trellises need NEC 690.12 rapid shutdown?
Not always. NEC 2023 added an exception clarifying that non-enclosed detached structures do not require NEC 690.12 rapid shutdown, which is especially relevant for canopies, carports, and trellises. Rooftop PV on occupied buildings is still a different case and usually remains within the rapid shutdown rules.
What should a permit package show if the design relies on UL 3741 or a PVHCS rapid shutdown method?
The plan set should clearly identify the compliance path, the specific listed equipment, and the rapid shutdown method shown on the one-line, roof plan, and label schedule. If the design relies on UL 3741 or a PV Hazard Control System, the submitted equipment and installation details should match the applicable listing and manufacturer documentation.
When does NEC 705.11 become important on a solar job?
NEC 705.11 matters when the PV system cannot use a straightforward load-side breaker connection and the interconnection needs to happen on the service side. That usually comes up when the main panel cannot accept more backfeed, the desired PV size is too large for the existing load-side equipment, or the service layout makes a standard interconnection impractical.
Does Article 706 commissioning apply to residential battery systems?
Not in the same way. Under 706.7, commissioning and maintenance record requirements apply to ESS installations other than one- and two-family dwellings, while residential systems have different practical requirements, including emergency shutdown expectations for dwelling units.
When is arc-fault protection required under NEC 690.11?
NEC 690.11 requires listed DC arc-fault protection or equivalent equipment for PV systems operating at 80 V DC or greater between any two conductors. It does not apply to PV arrays that are not mounted on or in buildings, or to certain DC output circuits installed in metallic raceways or metallic enclosures.
What should installers watch for in NEC 690.31 rooftop wiring and cable management?
For rooftop solar wiring, NEC 690.31 affects conductor polarity identification, grouping of DC and AC conductors, cable tray use, and support requirements for exposed conductors. NEC 2023 also expanded 690.31(C)(2) to give more specific rules for smaller single-conductor PV wires in cable trays, which makes conductor support, layering, and tray sizing more important in both design and field installation.