Fresno, California · 2022
Inland Star — First UL3741-Compliant PV Array
The first UL3741-compliant rooftop PV system in the U.S. — a 523 kW array in Fresno, CA built with FastRack 510-6dg and SMA CORE1 inverters, eliminating module-level power electronics and cutting connector count by 65%.
System size
523 kW-DC
Completed
2022
- Location
- Fresno, California
- Modules
- 1,101 × Trina TSM-457DE15V(I)
- Mounting system
- FastRack 510-6dg at 5° tilt
- Mount type
- Rooftop
Why this project worked
- First UL3741-compliant PV system deployed in the United States
- No module-level power electronics or rapid-shutdown devices required
- Paired with SMA CORE1 inverters for certified rapid shutdown
- Connector count reduced by 65% vs. traditional designs
Overview
This is the first UL3741-compliant PV system in the United States, built without module-level power electronics anywhere in the array. Sollega has delivered simple, robust racking for commercial and industrial flat-roof PV for over fifteen years, and the FastRack 510-6dg has now entered a new era of installation and production efficiency under UL3741 — eliminating the need for rapid-shutdown devices (RSDs).
Sollega and SMA America joined forces to certify the FR510-6dg with the SMA CORE1 inverters. It is the first system to market that complies with UL3741 Photovoltaic Hazard Control Systems (PHCS) and NEC 690.12 for rapid shutdown of rooftop PV systems without module-level power electronics or switches.
Adherence to UL3741-compliant inverters allows installers to connect module-to-module, avoiding incompatibility issues between connectors, reducing failure points, and greatly speeding up installation. A system that meets UL3741 without RSDs delivers both up-front and long-term O&M cost savings while reducing the number of connectors within the array by 65%.
Sollega provided 1,392 FR510-6dgs for 1,101 modules mounted at a 5° tilt, enabling a higher density of kilowatts per square foot. The one-piece FR510-6dg requires no assembly, and its universal design allowed for a quick, simple, and intuitive module install.
