Definition
UL 1741-SA (Supplement A, published 2016) is the inverter listing supplement that tested compliance with California Rule 21 Phase 1 and 2 smart inverter functions. Superseded by UL 1741-SB (2020) for new installations in most US jurisdictions.
Key Takeaways
- UL 1741-SA = 2016 supplement testing Rule 21 Phase 1 & 2.
- Superseded by UL 1741-SB (2020) for new installations.
- Existing UL 1741-SA installations grandfathered.
- See UL 1741-SB for current requirements.
Frequently Asked Questions
2 commonly searched questions about UL 1741-SA.
What is UL 1741-SA?
Supplement A to UL 1741, published 2016. Tested California Rule 21 Phase 1 (anti-islanding, ride-through) and Phase 2 (volt-VAR, volt-Watt) functions.
Can I still install UL 1741-SA inverters?
In most US jurisdictions for new installations: no. UL 1741-SB required. Existing UL 1741-SA installations grandfathered.
Need engineering-backed solar designs?
Heaven Designs delivers PE-stamped solar design packages, structural calculations, electrical engineering, and utility-compliant permit plans.
