Checked against primary sources 2026-08-24

Rapid shutdown does not turn the array off. Nothing turns the array off.

Renewables is the smallest subject area on the paper and the one nobody prepares. It is also where one idea, properly held, answers most of what gets asked.

Start with the fact everything else follows from

A photovoltaic module makes power whenever light lands on it. There is no off.

That is not a quirk, it is the reason Article 690 exists as its own article instead of a few paragraphs bolted onto the general chapters. Every other source in the book can be interrupted at its origin. A service has a transformer behind it. A generator has a prime mover you can stop. An array has the sun behind it and the sun is not switchable.

So the article cannot be built around de-energizing the source. It is built around limiting how much energized conductor is left once somebody opens a disconnect, and around telling everyone who might touch the building what is still live.

Hold that one sentence and a surprising amount of the article becomes predictable rather than memorized.

Why you cannot switch a PV source circuit off at a breaker

Opening a device downstream of the array does nothing to the conductors upstream of it, and on a PV system those conductors are on the roof.

On an ordinary branch circuit that does not matter, because the wire upstream of the breaker is inside the panel and the panel has a main. On a PV system the wire upstream of the disconnect runs along the eave, down the wall and through the attic, and it is still making voltage in daylight no matter what position any handle is in.

Direct current makes it worse in two specific ways, and both explain rules that otherwise look fussy.

• An alternating current arc crosses zero twice a cycle, and a great deal of switchgear design quietly depends on that moment to extinguish it. A direct current arc has no zero crossing, so it burns until something physically separates far enough. That is why the disconnects here are rated the way they are and why a general-purpose switch is not a substitute.
• An array is a current-limited source. Short a module and it delivers only modestly more current than it does at its operating point, which is why NEC 690.8 sizes circuits off a multiple of short-circuit current in the first place. A fault can sit there all day without ever drawing enough to open an overcurrent device.

Both facts point the same way. In PV the code leans on detection and on marking what stays live, rather than on the overcurrent device, because the source will not cooperate with an overcurrent device.

What rapid shutdown actually does

It shrinks the energized footprint to a small region around the array. It does not de-energize the array, and an answer choice saying it does is wrong on its face.

The function is written in terms of three ideas and an item is usually testing whether you know which one is which.

• Controlled conductors. The conductors the function acts on, which are the PV system conductors running away from the array toward the rest of the building.
• The array boundary. A defined region around the array, one foot from it in every direction. Conductors running more than three feet inside a building from their point of entry are treated as being outside it.
• The clock. Nothing about rapid shutdown is instantaneous. Every limit in the section is stated as a voltage reached within a period after the function is initiated.

The reason for all of it is a person with an axe. A firefighter cutting a ventilation hole, or throwing a ladder against a wall, needs to know what the conductors running past their hands will be doing a minute after somebody hit the switch on the outside of the building. Inside the array itself there is a limit to what can be promised, which is exactly why the boundary exists and why the two sides of it are not held to the same number.

The two limits, and which side of the line they sit on

Outside the boundary the limit is tighter, because that is where people are.

NEC 690.12(B)(1) holds controlled conductors outside the array boundary to not more than 30 volts within 30 seconds of rapid shutdown initiation. That is the number that matters to somebody standing on a roof or leaning a ladder on a wall, and 30 volts is chosen to be a level a person can be around.

Inside the boundary NEC 690.12(B)(2) offers a choice, and this is the part that has changed most across recent editions. One option is a listed PV hazard control system, a PVHCS, installed according to the instructions that come with its listing, and where that system needs to be told to go to its controlled state, the same rapid shutdown initiation device does the telling. The other option is a voltage limit: the highest voltage inside equipment, or between any two conductors of a circuit, or between any conductor and ground inside the array boundary, held to not more than 80 volts within 30 seconds of initiation.

So the shape of it is: same clock on both sides, different voltage. The tighter number is on the outside where the people are, and the looser number applies inside the array where a listed system may be doing the work instead.

NEC 690.12(C) is where the initiation device requirements sit, in three numbered paragraphs. Read them in your own book. They govern what the device is, where it goes and how it is marked, and they are short enough to read twice.

Maximum voltage, and the three ways the code lets you get it

Cold is the worst case, which is the first thing that catches people out.

A module's open-circuit voltage rises as it gets colder. A string that sits comfortably under an equipment rating on a July afternoon can climb past it on a clear January morning before the sun has warmed anything up. So the calculation is not done at a normal temperature, it is done at the lowest expected ambient temperature for the site.

NEC 690.7(A) gives three permitted methods and an exam item lives in the difference between them.

1. The general method. Take the sum of the modules' rated open-circuit voltage for the series string and correct it for the lowest expected ambient temperature using the module's own open-circuit voltage temperature coefficients. This one works for any module, because the coefficients come off that module's own listing.
2. The table method. For crystalline and multicrystalline silicon modules, correct the same sum using the correction factors in Table 690.7(A) instead. Note the restriction in the first four words. If the stem hands you a thin-film module, this method is not on the table for you, and a choice that uses it is wrong.
3. The engineered method. A documented and stamped PV system design using an industry standard method, provided by a licensed professional electrical engineer. Real, permitted, and not something you are going to do in a testing center, but worth recognizing as a legitimate third option when it shows up as an answer choice.

The habit to build: when a maximum voltage question appears, find the module technology in the stem before you find the numbers. Crystalline and multicrystalline silicon give you the table. Anything else does not, and a choice that reaches for the table anyway is wrong no matter how the arithmetic comes out.

Do not copy Table 690.7(A) onto anything. It is a table, it is in your book, and a table carried out of a secondary source is how people arrive at a confident wrong answer.

Two disconnects doing two different jobs

Separating these answers a whole family of items, and the section titles tell you the difference if you read them.

NEC 690.13 is the photovoltaic system disconnecting means. Its job is about the building: somebody wants the array off the premises wiring, and the disconnect is placed and marked so it can be found by a person who has never been to this address before.

NEC 690.15 is the equipment disconnecting means, and its job is about a technician. Equipment inside a PV system is fed from both directions at once. There is an array on one side and a utility or a battery on the other, so opening one of them leaves the equipment live from the other. The section is written around isolating a piece of equipment from all of its sources rather than from a source.

Marking goes with both, and a large part of the article is marking, because the system will outlive the installer and the next person to open the enclosure has no idea what is behind it.

What actually changed in Article 690 for 2026

Less than you have been told, and the useful news is that your section addresses still work.

The 2026 edition ran a standard template through the book that puts listing requirements at the .2 position of an article and reconditioned equipment at .3. Article 690 picked up a listing requirement at NEC 690.2. That position was vacant, so nothing behind it moved.

The addresses you already use are still the addresses. In the 2026 drafts, maximum voltage is at 690.7, rapid shutdown is at 690.12, the system disconnecting means is at 690.13, equipment disconnecting means is at 690.15, wiring methods are in the 690.31 area and equipment grounding runs through 690.43 and 690.45. If a course told you to distrust every number in this article, it cost you time for nothing.

That is not true everywhere in Chapter 5 and Chapter 6, which is the actual lesson. Some articles were reorganized wholesale and some were barely touched. Check the article you are in rather than applying one rule to the whole book.

The substantive 2026 work in this article went into 690.12(B)(2), the inside-the-boundary requirement, where the listed hazard control system option was tightened up. If you learned rapid shutdown from material older than the 2023 book, that is the paragraph to read again.

Renewables is more than Article 690

An item in this subject area can land in a neighboring article, because the outline names a technology and the book is organized by installation type.

• Article 705 covers interconnecting a power production source with other sources, which is where most questions about connecting to an existing service actually live.
• Article 706 covers energy storage systems, which is where a battery question goes.
• Article 710 covers stand-alone systems, the ones with no utility behind them at all.
• Article 691 covers large-scale photovoltaic electric supply stations, and NEC 690.1 draws the line by saying Article 690 applies to PV systems other than those covered by Article 691. If a stem describes a utility-scale generating station, you are in the wrong article.

So the first move here is the same as everywhere else in Chapter 6. Decide which article you are in before you read a requirement, because these articles cross-reference each other constantly and it is easy to land on a real paragraph answering a different question.

Three items, and why they are the cheapest on the paper

Renewable Energy Technologies is 2 of the 56 scored items on the journeyman NEC Knowledge portion and 1 of the 24 scored items on Calculations, per the PSI bulletin. It is the second smallest area on the knowledge outline, ahead only of control devices and disconnecting means.

Three items across the sitting, from a subject with one central idea, in articles almost nobody opens. The marginal point here is cheaper than the marginal point anywhere else on the paper.

Seventy percent passes, which leaves room for about sixteen wrong answers on the knowledge portion. Handing over three of them to a subject you decided not to read is most of a fifth of that margin, gone before you sit down.

1. Read the scope of Article 690 and the Article 100 definitions attached to it. Array boundary and controlled conductors are defined terms and 690.12 is unreadable without them.
2. Read 690.12 end to end in a 2026 book and write the two voltage limits and the clock on paper, from the book, in your own hand.
3. Read 690.7(A) and mark which method is restricted to crystalline and multicrystalline silicon. That restriction is the item.
4. Tab 690.13 and 690.15 and note in the margin which one is about the system and which is about equipment.
5. Open Articles 705, 706 and 710 far enough to read their scopes. Five minutes each, and it stops you answering a storage question out of the PV article.

One scheduling note. The examinations move to the 2026 National Electrical Code on 1 September 2026, the same day Texas adopts it under 16 TAC 73.100, so there is no version of this worth doing in an older book.

What this page cites

• NEC 690.12 Rapid shutdown. 690.12(B)(1) holds controlled conductors outside the array boundary to 30 volts within 30 seconds of initiation. 690.12(B)(2) covers inside the boundary, offering a listed PV hazard control system or an 80 volt limit within 30 seconds. 690.12(C) holds the initiation device requirements in three paragraphs. The inside-the-boundary text and the 80 volt and 30 second figures were verified against NFPA's Code-Making Panel 4 first and second draft reports for the 2026 edition. source
• NEC 690.7 Maximum voltage. 690.7(A) permits three methods: correction using the module's own open-circuit voltage temperature coefficients at the lowest expected ambient temperature, the correction factors in Table 690.7(A) for crystalline and multicrystalline silicon modules only, and a documented and stamped design by a licensed professional electrical engineer. Verified against the CMP-4 first and second draft reports. The table itself is not reproduced here. source
• NEC 690.13 Photovoltaic system disconnecting means, which separates the PV system from what it feeds. Distinct from 690.15, the equipment disconnecting means, which isolates a piece of equipment from all of its sources.
• NEC 690.2 Listing requirements, added by the 2026 template that puts listing at the .2 position of an article. The position was vacant in Article 690, so no other section in the article moved. The same template pattern is visible at 500.2 and 501.3 in the classified locations articles. source
• NEC 690.1 Scope. Says Article 690 applies to solar photovoltaic systems other than those covered by Article 691, and that Article 691 covers the installation of large-scale photovoltaic electric supply stations. source
• NEC 690.8 Circuit sizing and current. Why a PV circuit is sized from a multiple of short-circuit current rather than from an ordinary load.
• NEC Article 705 Interconnected electric power production sources. Where most questions about connecting an array to an existing service actually belong.
• NEC Article 706 Energy storage systems. Where a battery question goes. Article 710 covers stand-alone systems.
• 16 TAC 73.100 Texas adoption of the 2026 National Electrical Code, effective 1 September 2026. source
• IAEI Magazine, NEC Rapid Shutdown Requirements and UL 3741 Used for the array boundary dimension of one foot in all directions, the three foot distance inside a building, and the 30 volt limit outside the boundary. 690.12(B)(1) does not appear in either NFPA 2026 draft document, which is how we know it was not revised for this edition. source
• PSI Candidate Information Bulletin, TDLR Electricians Updated 9 July 2026. Renewable Energy Technologies is 2 of the 56 scored items on the journeyman NEC Knowledge portion and 1 of the 24 scored items on the Calculations portion. Both outlines read at source on 24 August 2026. source