SUNSPEC SPECIFICATIONS

The SunSpec Certified program for Rapid Shutdown verifies compliance to the SunSpec Communication Signal for Rapid Shutdown Functional Specification to meet the requirement established by National Electrical Code (NEC) 2017. PV module-level power control and safety (“rapid shutdown”) is required in 24 states starting in January 2019 and will affect millions of PV panels and all solar inverters. This standard is tested using UL 1741 SA criteria.

The SunSpec Communication Signal for Rapid Shutdown Specifications package includes:

• Rapid Shutdown Fact Sheet
• SunSpec Communication Signal for Rapid Shutdown Functional Specification
• SunSpec Communication Signal for Rapid Shutdown Test Specification
• PICS Template
• SunSpec Rapid Shutdown Prior Art Synopsis

Notice: Tigo and SunSpec were involved in legal disputes concerning certain of Tigo’s patents.  On November 3 2025, in the U.S. District Court for the Northern District of California, the parties agreed to settle pending disputes.  Although the terms of the parties’ settlement agreement are confidential, SunSpec is providing this notice pursuant to the parties’ settlement. Tigo has declared that some of its patents are necessary to the SunSpec Rapid Shutdown Specification, as shown in slide 8 of the PDF file located at the following URL: Rapid Shutdown Briefing.  While SunSpec takes no position on Tigo’s statement, SunSpec is aware that some of its members have obtained a license from Tigo.  Tigo lists licensees at the following URL: https://www.tigoenergy.com/rsdvirtualmarking.