Fronius Completes Rule 21 Inverter Certification

Fronius USA received UL certification for the Fronius Primo 10-15 kW and Fronius Symo 208V inverters to comply with California's Rule 21 inverter requirements. With that, all Fronius Primo and Symo inverters are now Rule 21 compliant.

Portage, IN, November 2017 - Fronius USA received UL certification for the Fronius Primo 10-15 kW and Fronius Symo 208V inverters to comply with California's Rule 21 inverter requirements. With that, all Fronius Primo and Symo inverters are now Rule 21 compliant.


Rule 21 refers to the generator interconnection requirements of each California Investor-Owned Utility (IOU). A years-long process has been underway to update Rule 21 with "smart inverter" requirements. Rule 21 requires inverters to have new grid support functions and a new certification under UL 1741 SA. Each new inverter also gets a new nameplate label that identifies it as a "Grid Support Utility Interactive Inverter."

New smart functions, such as voltage and frequency ride-through or soft start ramp rate, will pave the way for further solar penetration into the California grid and help to better manage the fluctuations caused by distributed energy resources (DER). These new functions have a stabilizing effect on the grid as more DER is added to it. Fronius has always been a driving force when it comes to inverters' Grid Support Functions and has years of experience from highly solar-penetrated markets such as Germany or Italy.

Fronius is currently shipping Rule 21 compliant residential inverters (the Fronius Primo 3.8-8.2 kW) and commercial inverters (the Fronius Symo 10.0 - 24.0 480V). Beginning November 6, 2017, the Fronius Primo 10-15 kW and the Fronius Symo 208V models will also ship with Rule 21 compliance. For more information on ordering your Rule 21 compliant smart inverter, please contact your local Fronius distributor.


About Fronius
Fronius USA LLC, headquartered in Portage, Indiana, is a leading manufacturer for solar solutions and has been shaping the US solar industry since 2002. The company is the biggest subsidiary of Fronius International GmbH, headquartered in Austria. Fronius has three divisions: Perfect Welding, Solar Energy and Perfect Charging. Through innovation and new technologies, Fronius has become a leading resource for high quality solutions in each industry they serve. Fronius innovation is guided by a vision of 24 hours of sun, a future where 100% of energy needs are covered by renewable energy.

For more information visit www.fronius-usa.com.

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