Rapid Shutdown Compliance Checker

It requires that a photovoltaic array can be brought to a low-voltage state quickly by a single deliberate action, so emergency responders are not working around live DC conductors. The requirement is built around the array boundary, a zone drawn roughly a metre outside the array in any direction, and the two zones carry different limits. Outside the boundary — the conductor run from the roof down to the inverter or combiner — the requirement is 30 volts or less within 30 seconds of initiation. Inside the boundary, meaning the wiring between and beneath the modules themselves, the 2017 edition and later require 80 volts or less within 30 seconds, or a listed PV hazard control system. They are separate obligations and a system can satisfy one while failing the other.

Because the edition decides which zone rules are in play, and therefore what the equipment has to be able to do. The outside-boundary rule arrived with the 2014 edition. The inside-boundary rule arrived with the 2017 edition and took effect on 1 January 2019. A design that satisfies the 2014 edition can be entirely non-compliant under the 2017 edition without anything about it being wrong in 2014 terms. Asking the readiness questions before the edition is established produces a confident answer to the wrong question, which is why the tool refuses to resolve past an unestablished edition.

Not as a matter of code language, but very nearly as a matter of physics. The inside-boundary requirement means the voltage between modules must collapse, and a series string cannot do that on its own because each module keeps producing while the sun is on it. Something must act at or near each module: a microinverter, which converts at the module and leaves no high-voltage DC on the roof, or a DC optimiser with a rapid shutdown function that drops its output on loss of the keep-alive signal. The listed PV hazard control system route is the code's stated alternative and is used on some commercial designs. For most residential roofs the answer is module-level electronics.

It means the combination was evaluated, not just the parts. An optimiser and an inverter must be listed as a rapid shutdown system together, and mixing brands or substituting a model mid-project breaks that listing even where both components are individually certified. This is the one item on the readiness list that cannot be closed with paperwork: a documentation gap is fixed by adding documents, a location gap by relocating a device, but a combination that was never evaluated together is fixed by changing the equipment. It is worth catching in design rather than at the point the correction notice arrives.

Because the specified format changed between editions and the templates did not. NEC 690.56(C) requires a permanent sign at the service equipment or at the rapid shutdown initiation device, identifying that the building has a photovoltaic system with rapid shutdown and indicating what the shutdown covers. Later editions specify a particular format, including a simplified diagram distinguishing conductors that remain energised inside the array boundary from those that do not, along with required wording and colour. A label printed from an older template can be technically wrong while being present, permanent and perfectly legible, which is why this is the most common single cause of failure on otherwise clean installations.

Frequently yes, and it catches people out. Work on an existing array is generally assessed against the code edition in force at the time of the new permit application, not the edition the original system was built to. A system installed under the 2014 edition satisfied only the outside-boundary rule and may have plain string wiring on the roof. Extending it can bring the whole array, or at minimum the modified portion, within the current inside-boundary requirement, which can mean retrofitting module-level devices to modules that never had them. Whether the requirement lands on the new modules alone or on everything is an AHJ interpretation and it varies, so the code edition question belongs in the quote.

It means nobody has checked, which is a different state from a pass or a fail. Four of the five readiness items are routinely assumed rather than verified — the label is assumed to be the current format, the listing is assumed because both parts are certified, the functional test is assumed because the system switched on. The tool reports an unanswered item as open rather than resolving it, because a submission built on assumptions is how a system that would have passed does not.

No. It reproduces the structure of NEC 690.12 and the associated labelling requirement as commonly adopted, and the authority having jurisdiction decides. Jurisdictions adopt different NEC editions on their own schedule, some amend them, and inspectors differ on what they will accept for initiation device location. Use this to know which questions decide the answer and what evidence each one needs, then confirm with the department that will inspect the work.