his section includes products that comply with 2014 NEC code 690.12 – Rapid System Shutdown.
First responders (ie. firefighters) must contend with elements of a PV system that remain energized after the AC service disconnect is opened. This rapid shutdown requirement provides a zone outside of which the potential for shock has been mitigated. 10 seconds allows time for DC capacitor banks to discharge.
Now, emergency responders are able to de-energize the entire solar array within 10 seconds from a clearly-marked central switch before venturing onto a rooftop for firefighting.