The Impact of NEC 690.12 on Rapid Shutdown in Solar Systems: An In-Depth Look

Home The Impact of NEC 690.12 on Rapid Shutdown in Solar Systems: An In-Depth Look

When you think about solar power, the image of sunny skies and clean energy comes to mind, right? But there’s more to it than just harnessing the sun’s energy. When we tap into this power, we must do it safely. Enter NEC 690.12. If you’re part of the solar industry or a homeowner with solar panels, you’ve probably encountered this section of the National Electrical Code. NEC 690.12 is critical for ensuring that solar systems can be shut down rapidly and safely in case of an emergency, protecting both first responders and the system’s integrity.

We live in a time where technology moves faster than a toddler with a sugar rush, and safety regulations hustle to keep pace. NEC 690.12 has had its fair share of updates, ramping up safety standards with each iteration. Understanding these updates is crucial. Why? Well, because compliance isn’t just about ticking boxes—it’s about ensuring that when you need a rapid shutdown (and let’s hope it’s only ever a drill), your solar PV system isn’t going to argue, it’s going to act—fast.

nec 610.12

The Evolution of NEC 690.12 in Solar System Safety

It’s no secret that solar system installations have skyrocketed in popularity. However, with great power (quite literally) comes great responsibility. NEC 690.12 initially entered the scene to address the shock and fire hazards posed by live electrical conductors during an emergency. Since then, with every tick of the clock, we’ve seen advancements in PV technology, and accordingly, the National Electrical Code has evolved to match these leaps.

Starting its life in the 2014 edition, NEC 690.12 laid the groundwork for rapid shutdown, primarily focusing on accessible AC and DC conductors and their respective shutdown methods. The implications for solar installations were significant, insisting upon solutions to de-energize live conductors that could pose a threat during firefighting or maintenance operations. Fast forward to NEC 2017, and we’re not just talking evolution; we’re discussing a full-blown metamorphosis. The 2017 updates demanded more stringent control of DC conductors within the solar array, specifying that they must be reduced to safe voltage levels within an arm’s reach—or more technically, within 1 ft of the array boundary upon shutdown initiation.

Building on the foundation set by previous editions, NEC 2020 introduced more nuanced requirements for rapid shutdown systems, emphasizing the safety of emergency responders. It specified that within the solar array, the voltage must be reduced to 80 volts or less within 30 seconds of shutdown initiation, extending the safe zone to 1 foot outside the array boundary. This represented a significant step towards enhancing safety around solar installations, particularly in residential and commercial settings.

Advancing into NEC 2023, the code continues to evolve with the solar industry’s growth and technological innovation. It refines the rapid shutdown requirements further, streamlining the compliance process and adapting to newer technologies in solar installations. The 2023 edition emphasizes practical and adaptable safety standards, reflecting a deeper understanding of the intricacies involved in modern solar PV systems and the necessity for increased safety measures in diverse installation environments.

Detailed Overview of NEC 2017 Updates

Changes from NEC 2014 to NEC 2017

The transition from NEC 2014 to NEC 2017 marked a pivotal shift in the standards governing PV system safety. Initially, NEC 2014 primarily targeted the management of AC systems with some attention to DC systems, aiming to minimize electrical shock risks. However, the 2017 updates raised the safety bar significantly, bringing profound changes to the way DC conductors are managed. A pronounced emphasis was placed on expanding the scope and stringency of rapid shutdown requirements for DC conductors—those most hazardous components of PV systems in emergency situations.

Building on this critical focus, the 2017 modifications in NEC brought forth comprehensive changes:

  1. GFCI Protection: NEC 2017 increased the safety protocols around Ground Fault Circuit Interrupters (GFCIs), which are crucial for preventing electrical shocks. The code now requires GFCIs for all outlets with a risk of moisture exposure and clarified their use in specific applications.
  2. Solar Photovoltaic (PV) Systems: One of the more substantial changes was the expansion of rules regarding the rapid shutdown of PV systems. The code added clarity on the use and labeling of equipment, ensuring that first responders could easily identify rapid shutdown equipment.
  3. Wiring Methods: NEC 2017 updated wiring methods to improve the installation safety standards for PV systems. It addressed concerns surrounding the routing, identification, and grouping of PV system conductors.
  4. Energy Storage Systems: Understanding the rising interplay between solar systems and energy storage solutions, the NEC optimized guidelines on their installation and maintenance. The 2017 code revisions featured clearer direction on spacing, disconnection means, and labeling requirements associated with new and existing energy storage systems.
  5. Rapid Shutdown of PV Systems: Perhaps the most talked-about update was the refinement of rapid shutdown system requirements for PV. The 2017 code specified that PV systems installed on or within buildings must reduce the voltage of DC conductors to 30 volts or less within 30 seconds of rapid shutdown initiation. It also expanded the scope by specifying controlled conductor requirements within 1 foot of a PV array.

Impact of NEC 2017 on Solar Installations

The NEC 2017’s overarching impact saw the solar industry undergoing a paradigm shift in both the execution of installations and the development of new technologies compliant with the updated codes. A spotlight shone on rapid shutdown devices (RSD), requiring engineers and system designers to incorporate these safety mechanisms consistently across new systems and retrofits. An informational note in 690.12(C)(3) has been updated to acknowledge that an RSD switch can serve standby systems as well as standalone systems (which may not have a PV AC disconnect to initiate RSD).

In line with the expanded rapid shutdown provisions, installations took on a new rhythm; workflows were reassessed, and safety measures amplified. Technicians were introduced to a new breed of initiating devices designed to meet not only the swift reactive nature mandated by the shutdown requirements but also compatible with the intricate engineering of modern solar systems.

These alterations carried a cost impact, notably discernible in large-scale solar projects where the necessity for robust, cutting-edge shutdown apparatus was now not just a recommendation but a compliance necessity. The stringent requirements ushered in by NEC 2017 transformed the landscape of solar systems. Compliance was no longer just a checklist item—it became a dedicated pursuit of heightened safety in solar power generation. This renewed approach set a precedent, establishing a benchmark that would guide the industry standards forthwith.

Introduction to NEC 2020 Updates

Overview of New Changes in NEC 2020

Just when we thought we’d grasped the nuances of NEC 2017, along came the NEC 2020 updates to take solar safety standards to new heights. Time doesn’t stand still, and certainly not for the NEC which, much like a guardian of the solar realm, has been indefatigably ensuring that our burgeoning reliance on solar power does not come at the cost of safety. The 2020 iteration of the NEC maintained its steady gaze on safeguarding both system integrity and human lives. But this time, it wasn’t just about solidifying the pv installation requirements by its predecessor, but about refining those procedures.

  1. Ground Fault Circuit Interrupters (GFCIs): NEC 2020 has heightened the scope of GFCI protection to ensure safety in diverse applications. Specifically, all 125-250V receptacles located within 6 feet of the sinks must be equipped with GFCI protection. Furthermore, NEC has expanded GFCI requirements to cover all outlets rated at 150 volts to ground or less in areas not exceeding 50 amperes, directly affecting areas where PV systems could increase risks of electrical shocks due to ground faults.
  2. Solar Photovoltaic (PV) Systems: Article 690 in NEC 2020 demystifies the application of various sections to solar PV systems. The code now emphasizes precise temperature correction factors for conductor sizing, requiring that these factors account for temperature impacts from different roof assembly configurations.
  3. Wiring Methods: Emphasizing durability, NEC 2020 outlines wiring methods suitable for DC and AC circuits in PV systems. It specifies that conductors must be routed with a temperature correction factor, taking into account whether the conductors will be exposed to direct sunlight and stipulating the use of more durable wires if within a particular proximity to the rooftop—7/8 inches or more requires temperature adders.
  4. Energy Storage Systems: Responding to the combination of solar and storage technology, NEC 2020 codifies guidelines for safe energy storage integration. The provisions necessitate labeling the energy storage disconnecting means and sizing overcurrent protection devices in line with the maximum current provided by the storage system manufacturer, thus safeguarding the system’s integrity.
  5. Rapid Shutdown of PV Systems: Continuing from NEC 2017, NEC 2020 advances rapid shutdown systems (RSS), crystallizing the criteria for control limits around the PV array. PV systems on or within buildings lower conductor voltage to less than or equal to 30 volts within 30 seconds of initiation. The controlled conductors’ voltage be reduced to 80 volts or less within 30 seconds of rapid shutdown initiation. Notably, the controlled conductors located inside the boundary are now required to be limited to 1 foot in length, reinforcing emergency responder’s safety during critical situations.

How NEC 2020 Affects Solar Rapid Shutdown

NEC 2020 catapulted solar rapid shutdown requirements into a new era. The mandate that PV system circuits within and just beyond building perimeters reduce to 80 volts or less within 30 seconds of shutdown initiation marked a profound advancement in safety protocols. These aren’t simple cosmetic alterations to existing plans—these are transformative and rigorous demands calling for widespread modifications across the industry.

For string inverter systems, which traditionally managed shutdowns at the inverter level, this meant an overhaul in approach. Compliance now required integrating module-level power electronics (MLPEs) to achieve granular control over each solar panel. Such sophistication was no longer an option but a necessity. Installers and designers ramped up their efforts to integrate these technologies into their systems, ensuring they could offer rapid shutdown solutions without compromising on efficiency or performance.

This seismic shift sparked an evolution towards smarter, more responsive PV systems. The ability to meet rapid shutdown requirements became a critical factor in product design and selection, driving innovation within the solar industry. As a result, compliance with NEC 2020 is serving as a catalyst for technological advancement, reinforcing the solar sector’s commitment to safety and adaptability in an ever-evolving energy landscape. Thus, NEC 2020 didn’t just adjust the way we conceive of and interact with solar systems; it redefined the benchmarks by which such systems are engineered and measured.

NEC 2023: The Latest in Solar Rapid Shutdown

What’s New in NEC 2023?

NEC 2023 once again updates standards to match the evolving technologies and practices within the solar industry, including subtle yet essential changes:

  1. Ground Fault Circuit Interrupters (GFCIs): NEC 2023 underlines the expansion of GFCI requirements to encompass common solar installer job sites, insisting that garage outlets under 50 amps and grounded outlets under 150V are GFCI-protected. This protection reaches further into locations prone to moisture risks, tightening safety in installation environments.
  2. Solar Photovoltaic (PV) Systems: Article 690, critical for solar installers, underwent a linguistic overhaul, seamlessly streamlining system component and concept descriptions. Notably, the phrase ‘PV output circuit’ was removed, with ‘PV string circuit’ employed for clarity. Innovations like ‘floatovoltaics’—solar arrays on water—demanded new considerations for wiring amidst movement, while with AC modules, language now minimizes confusion around equipment inclusion in code requirements.
  3. Wiring Methods: Article 690, Part IV, gains clarity from restructured subsections on wiring methods, addressing Serviceability and Conductor Ampacity. The guidance now extends to cable trays handling wires smaller than 1/0 AWG and specifications for systems exceeding 1000V DC, prohibiting installation on one- or two-family dwellings and within habitable rooms, emphasizing elevation above ground.
  4. Energy Storage Systems: As the storage sector grows, NEC extends Article 706 to encompass notions like system commissioning upon installation and maintenance logging. Moreover, disconnecting means for energy storage in dwellings now include locations and control specifics, also delineating shutdown requirements and approved device locations.
  5. Rapid Shutdown of PV Systems: NEC 2023 continues its trajectory toward refining Rapid Shutdown Device (RSD) regulations with the removal of color and reflectiveness label specifics, instead focusing inspectors on label content. Extensions to exceptions around rapid shutdown devices are noted, particularly for arrays detached from buildings and non-enclosed structures, presenting relaxed RSD expectations for certain installations.

NEC 2023 fosters a safer and clearer framework for solar PV system implementation, better protection with GFCIs, improved clarity in nomenclature, and refined considerations for floatovoltaics, high-voltage systems, and energy storage. Additionally, RSD requirements have been modified to suit modern systems and installation scenarios. These updates collectively establish a brighter and more secure future for solar power integration.

Preparing for Future Code Updates

In the realm of electrical standards, the NEC’s updates are as inevitable as the rising sun. With the 2023 NEC having unfolded its pages of revisions, the focus now shifts not just to grasping these changes but also to methodically weaving them into the fabric of our daily work. For professionals in the solar industry, this translates to an active pursuit of knowledge—immersing oneself in the current code’s specifics, its practical implications, and the strategic application within solar projects.

As the NEC continues to evolve, aligning with its rhythm is crucial. This alignment is more than mere compliance; it is an intentional journey alongside the ever-advancing tide of industry standards. For the professional and homeowner alike, it’s about keeping an intuitive eye on the horizon, watching how these changes mold the landscape of solar installations, and adapting preemptively. It’s about understanding that readiness for code updates is not a one-time adjustment but an ongoing posture of preparedness—ready to absorb, implement, and advocate for best practices that resonate with the beat of the NEC.

This readiness involves not only keeping one’s skills and knowledge razor-sharp through continuous education but also deploying this expertise in practical scenarios. Sharp attention to the fine print of the NEC’s newest code changes means solar installations can not only meet the stringent benchmarks of safety and efficiency but also preempt the future trajectory of solar regulations. By embodying a forward-thinking approach and proactively piecing together the puzzle of regulatory changes, solar professionals don’t just respond to the NEC’s cadence—they actively contribute to the symphony of a safer, more robust solar future.

State-by-State Adoption of NEC Standards

Overview of NEC Compliance Across the United States

Solar system safety isn’t just a federal matter—it’s a state one too. Even as NEC rolls out these updated standards, each state has the autonomy to adopt and enforce them as they see fit. It’s a patchwork quilt of compliance, where some states adopt immediately and others may lag, leading to a spectrum of safety and performance standards across the country. It’s essential for installers and designers to have their fingers on the pulse not only of the NEC but also of the local codes and amendments.

State-Specific Adoption of NEC 2023

Considering the NEC 2023, you’re looking at an ever-evolving scenario where some states might still be catching up with NEC 2017 or NEC 2020. State-by-state adoption means staying nimble and adaptable, understanding that while the rapid shutdown, pv rapid shutdown, or even module level rapid shutdown requirements are standardized in the NEC, implementation can differ wildly by jurisdiction. We’re already seeing a growing number of states aligning with the latest standards, recognizing the safety and consistency benefits that come with it.

The table originates from the National Fire Protection Association (NFPA) and displays the current version of the National Electrical Code (NEC) adopted by states with statewide regulations that impact construction, trade licensing, or both.

StateNEC Adoption Status (Effective Date)Notes
AlabamaAdopted NEC 2020 (7/1/2022)
AlaskaAdopted NEC 2020 (4/16/2020)
ArizonaLocal adoption only
ArkansasAdopted NEC 2020 (8/1/2022)
CaliforniaAdopted NEC 2020 (1/1/2023)
ColoradoAdopted NEC 2023 (8/1/2023)
ConnecticutAdopted NEC 2020 with CT amendments (10/1/2022)
DelawareAdopted NEC 2020 (9/1/2021)
FloridaAdopted NEC 2020 (12/31/2023)
GeorgiaAdopted NEC 2020 with GA amendments (1/1/2021)2023 update process underway (Projected 1/1/2025)
HawaiiAdopted NEC 2020 (3/14/2023)
Idaho2023 (7/1/2023) with ID amendments (temporary rules permit use of 2017 NEC w/ID amendments)
IllinoisAdopted NEC 2008 (7/1/11 – commercial occupancies for areas outside of local jurisdictions that have adoption authority)
IndianaAdopted NEC 2008 Commercial with IN amendments (8/26/2009)2017 (2018 IRC) One- and two-family dwellings with IN amendments (12/26/2019)2023 Update process underway (Effective date not established)
IowaAdopted NEC 2020 with IA amendments (4/1/2021)2023 update process underway (Effective date not established)
KansasAdopted NEC 2008 (2/4/11 – State Fire Marshal)
KentuckyAdopted NEC 2017 (1/1/2019)2023 update process underway (Effective date not established)
LouisianaAdopted NEC 2020 (1/1/2023)
MaineAdopted NEC 2020 with Maine amendments (7/2/2021)
MarylandAdopted NEC 2017 (2/7/2020)
MassachusettsAdopted NEC 2023 with MA amendments (2/17/2023)
MichiganAdopted NEC 2017 Commercial (1/4/2019) One- and two-family dwellings (2/8/2016)2023 update process complete Commercial (3/12/2024) Residential 2023 update process underway (Effective date not established)
MinnesotaAdopted NEC 2023 (7/1/2023)
MississippiLocal adoption only
MissouriLocal adoption only
MontanaAdopted NEC 2020 with MT amendments (6/10/2022)
NebraskaAdopted NEC 2017 (8/1/17)
NevadaAdopted NEC 2017 (7/1/18 – Nevada State Pubic Works Division)
New HampshireAdopted NEC 2020 with NH amendments (7/1/2022 with 6-month grace period permitting use of prior adopted edition)2023 update process underway (Effective date not established)
New JerseyAdopted NEC 2020 with NJ amendments (9/6/2022)
New MexicoAdopted NEC 2020 (3/28/2023)
New YorkAdopted NEC 2017 (5/12/2020)2023 update process underway (Effective date not established)
North CarolinaAdopted NEC 2020 with NC amendments for other than one- and two-family dwellings (11/1/21)2023 update process underway (Projected 1/1/2025)
North DakotaAdopted NEC 2020 (1/1/2021)2023 update process underway (Effective date not established)
OhioAdopted NEC 2017 Commercial (11/1/2017)NEC 2017 with OH amendments Residential (7/1/2019)2023 complete for Commercial (Effective 3/1/2024)Residential (Effective date projected first quarter of 2024)
OklahomaAdopted NEC 2020 (9/14/22)2023 update process underway (projected 9/14/2024)
OregonAdopted NEC 2023 with OR amendments (10/1/2023)
PennsylvaniaAdopted NEC 2017 (2/14/2022)2020 update process underway (projected 7/13/2025)
Rhode IslandAdopted NEC 2020 (2/1/2022)
South CarolinaAdopted NEC 2020 with SC amendments (1/1/2023)
South DakotaAdopted NEC 2020 (7/1/2020) with SD amendments2023 update process underway (Effective date not established)
TennesseeAdopted NEC 2017 (10/1/2018) with TN amendments
TexasAdopted NEC 2023 (9/1/2023)
UtahAdopted NEC 2020 Commercial (7/1/2021) with UT amendmentsNEC 2014 Residential (7/1/2016) with UT amendments
VermontAdopted NEC 2020 with VT amendments (4/15/2022)
VirginiaAdopted NEC 2017 (7/1/2021)2020 update complete (Effective 1/18/24)
WashingtonAdopted NEC 2020 (10/29/2020)2023 update process underway (projected 4/1/2024)
West VirginiaAdopted NEC 2020 with WV amendments (8/1/2022)
WisconsinAdopted NEC 2017 Commercial (8/1/2018) Residential (1/1/2020)
WyomingAdopted NEC 2023 (7/1/2023)
ChicagoAdopted NEC 2017 with Chicago amendments (3/1/2018)
New York CityAdopted NEC 2008 w/NYC amendments (7/1/2011)2020 update process underway (Effective date not established)
Source: National Fire Protection Association (NFPA)
nec 610.12
Source: National Fire Protection Association (NFPA)
nec 610.12
Source: National Fire Protection Association (NFPA)

The Role of Module Level Power Electronics (MLPE) in NEC 690.12

Module Level Power Electronics (MLPE) have become an indispensable part of contemporary solar systems, especially with evolving NEC specifications. These smart components, including module level rapid shutdown, microinverters and DC power optimizers, grant us the finesse to comply with the current NEC 690.12 regulations. MLPE technology allows for precise control over each solar module’s output, ensuring that in the case of a rapid shutdown, voltage levels can be brought down to NEC-mandated levels almost instantly. This is a crucial benefit, particularly in light of NEC 2020’s enhancements where power on both AC and DC conductors must be de-energized swiftly and safely.

The deployment of MLPE is not without its challenges though. Increased complexity in installation, heightened costs, and potential for additional points of failure are genuine concerns. However, the safety and compliance benefits currently outweigh these issues, making MLPEs a common feature in residential and commercial solar systems. For the solar professional, continued education on MLPE technology’s best practices is now more necessity than choice. The future of rapid shutdown compliance is inherently tied to MLPE implementation, making their role a pivotal one in the solar landscape.

NEC 690.12 in Residential vs. Commercial Solar Systems

Solar solutions are not one-size-fits-all, and when we dive into NEC 690.12’s role in residential versus commercial systems, the differences become clear. Residential installations typically involve either rooftop or ground-mounted systems. With rooftop applications being most common, the requirements for a rapid shutdown initiation device become particularly stringent due to close proximity to living spaces and the potential for emergency responder interaction.

Commercial systems, on the other hand, could span massive areas and incorporate complex setups like carport canopies or large-scale ground arrays. The need to protect emergency responders is still paramount, but the application of NEC 690.12 demands a more scalable approach. There might be larger boundaries to consider and multiple layers of rapid shutdown—whether at the module level, string level, or specific conductors. Compliance for commercial setups can be a jigsaw, piecing together NEC requirements with real-world system idiosyncrasies.

How to Inspect Rapid Shutdown Compliance with NEC 690.12?

Inspection and verification of rapid shutdown compliance are where the rubber meets the road. An inspector’s role involves a blend of expert knowledge of the NEC code language and hands-on inspection of solar PV systems. Inspectors armed with the intricacies of the NEC 690.12 are tasked with ensuring that safety standards are met, and must verify initiation device rules, the functionality of rapid shutdown devices (RSDs), and that the PV system circuits adhere to voltage and timing requirements.

Pre-inspection due diligence should include reviewing system schematics for RSDs and asking key questions about the rapid shutdown function. When on-site, inspectors utilize specialized tools to measure voltage within the system and observe the rapid shutdown initiation methods to confirm it complies with the critical 30-second timeframe. Moreover, inspectors serve as the frontline of safety and act as educators for installers, often advising on best practices and helping to enforce the overall intent of NEC 690.12.

Retrofitting Older Solar Systems to Meet New Standards

In the waves of change, there are many solar systems installed before the latest iterations of NEC 690.12. Retrofitting these systems to meet current standards is an opportunity for both enhanced safety and business growth. Older systems might lack the rapid shutdown capabilities or may have conductors that do not cut the mustard when it comes to voltage and distancing requirements.

The retrofitting process typically involves adding or replacing components with MLPEs, upgrading string inverters to smarter models, and ensuring there’s solid communication between the initiation device and the RSDs. It’s a delicate dance that involves respecting the integrity of the existing system while ushering it into compliance with contemporary codes. Nevertheless, for the safety-savvy and progressive-minded homeowner or business owner, retrofitting is a step toward peace of mind and regulatory compliance.

Beny’s RSD Solution: Ensuring NEC 690.12 Compliance in Solar Systems

To be compliant with NEC 690.12, installers now have more tools at their disposal than ever before, and Beny’s Rapid Shutdown Device (RSD) solution is among the vanguards. Designed to integrate seamlessly with a variety of solar system configurations, Beny’s solution caters to both the spirit and the letter of the rapid shutdown requirements. These RSDs ensure that solar panel rapid shutdown can be initiated promptly, maintaining voltage levels within the safe range dictated by NEC.

Beny’s RSD is an example of a system that not only meets CE, UL standards and current regulations but is designed with future iterations in mind. By emphasizing ease of use, compatibility with different kinds of PV panels, and a nod to future code evolution, solutions like these are prime examples of industry responses to the moving target that is NEC compliance.


Staying ahead of the curve in terms of NEC 690.12 compliance is no small task. From understanding the language of the code to implementing the nitty-gritty details of a compliant rapid shutdown system, there’s much to ponder. Yet, this doesn’t need to be a journey taken alone. Educational resources, professional courses, and a robust exchange of knowledge within the industry can help us navigate this landscape.

This detailed examination of NEC 690.12 and its implications for solar system safety underlines the commitment to protecting emergency responders and maintaining system integrity. As we journey through NEC changes and tread the path of solar innovation, let’s remember the ultimate goal: harnessing the sun’s boundless energy, all the while grounding our efforts in the bedrock of safety.

Talk to Our Expert