If you’ve just installed a solar panel system or are looking at a picture of one, you may notice a box with an on/off switch that says “rapid shutdown.” But what does rapid shutdown mean, and why is it important for a solar panel system?
The ERS module rapid shutdown units are part of PV Rapid Shutdown solution to meet 2017 NEC 690.12 specifications. PVRSS certified module-level rapid shutdown is enabled when ERS products are installed with 25/50/60kW inverters (ERS RSD wire-box version available).
The ERS Rapid shutdown device allows connections of up to four PV modules per device to meet 2017 NEC 690.12 specifications. This solution includes a gateway for module-level monitoring.
The initiation device(s) shall initiate the rapid shutdown function of the PV system. The device “off” position shall indicate that the rapid shutdown function has been initiated for all PV systems connected to that device. For one-family and two-family dwellings, an initiation device(s) shall be located at a readily accessible location outside the building.
The rapid shutdown initiation device(s) shall consist of at least one of the following:
(1) Service disconnecting means
(2) PV system disconnecting means
(3) Readily accessible switch that plainly indicates whether it is in the “off” or “on” position
Informational Note: One example of why an initiation device that complies with 690.12(C)(3) would be used is where a PV system is connected to an optional standby system that remains energized upon loss of utility voltage.
Where multiple PV systems are installed with rapid shutdown functions on a single service, the initiation device(s) shall consist of not more than six switches or six sets of circuit breakers, or a combination of not more than six switches and sets of circuit breakers, mounted in a single enclosure, or in a group of separate enclosures. These initiation device(s) shall initiate the rapid shutdown of all PV systems with rapid shutdown functions on that service. Where auxiliary initiation devices are installed, these auxiliary devices shall control all PV systems with rapid shutdown functions on that service.