NEC 690.12 is being put in place to keep first responders safe. When on site for an emergency, first responders can turned off the AC disconnect and this will deactivate the inverter. However, there is still DC power flowing on the roof that could potentially injure emergency workers.
Rapid shut down requires that conductors more than 5 feet inside a building or more than 10 feet from an array will be limited to a maximum of 30 V and 240 VA within 10 seconds of shutdown.
How is this achieved?
- Microinverters are already compliant (hooray!)
- However, string inverters will require additional equipment to make disconnect at the module possible
Related: New Placard requirement
690.56(C) a placard should be provided that reads “Photovoltaic System Equipped with rapid shutdown”