New safety standard for PV hazard control

Underwriters Laboratories, a U.S. nonprofit standards development organization, has published the new UL 3741 safety standard, which is related to the evaluation of PV hazard control functions.

“The standard is specifically intended to establish and expand requirements to help keep firefighters out of hazardous current paths when responding to emergency situations in homes and buildings with PV systems,” Underwriters Laboratories said. “Systems that comply with UL 3741 should also decrease potential hazards for others working in and around the PV array.”

The standard, which has been approved by the American National Standards Institute (ANSI) and the Standards Council of Canada (SCC), offers significant consistency in terms of PV hazard control, across both countries and jurisdictions.

“In addition, UL 3741 may reduce potential trade barriers by allowing manufacturers to design and evaluate products for both countries,” Underwriters Laboratories explained.

UL 3741 is the result of a decade of research conducted by the UL Firefighter Safety Research Institute, in cooperation with Sandia National Laboratories. Their work included research into electric shock parameters for ungrounded and grounded PV arrays, hazard-controlled states for PV system operation under emergency conditions, body impedance models, and corresponding shock thresholds for male and female firefighters with personal protective equipment.

*The article was amended on December 12 to specify the Underwriters Laboratories is a U.S. nonprofit standards development organization.