Hoffman/Pentair Technical Products and OneSource Distributors Co-Develop Combiner Box to Meet Latest UL Ratings at Higher 1,000 Volts DC Operation

Hoffman/Pentair Technical Products supplied critical components to OneSource Distributors, Orange, CA and their integrator partner Custom Process Solutions, Lake Forest, CA for the development of an ETL listed combiner box assembly that satisfies the new UL 1741 standard at 1,000 VDC. The combiner box is the first 1,000 VDC box in North America to meet the new photovoltaic standard certification.

Critical components supplied by Hoffman for development of the 1,000 VDC combiner box include:

• Wöhner PV fuse holders and busbar: Satisfy newly established UL 4248-18 outline of investigation
• 1,000 VDC DC-rated disconnect switch: ETL recognized to the UL 98B outline of investigation

While higher 1,000 VDC operation is common in European markets, the standards for UL—used throughout North America—were, until recently, written under system voltage at 600 volts. This lower operation is less efficient due to voltage drop over large areas, typically experienced in large solar fields that expand over hundreds of acres. Hoffman led the North American market in testing components to the newest standards, meeting a customer request to support more efficient and cost-effective operation—while still protecting wires and ensuring conductors do not short circuit or otherwise malfunction.

The Custom Process Solutions combiner box design satisfies the demanding system requirements of SunEdison and their 54 MW facility, which is currently under construction in Lea and Eddy counties in Southeastern New Mexico. This installation—which is scheduled for grid connection by the end of 2011—is expected to generate 112 million kWh of electricity in its first year of operation.

“Hoffman has a history of testing their innovative products to the highest standards, ensuring reliable and long-lasting product performance,” said Kei Cheung, Global Category Manager at Pentair Technical Products. “By testing components to the forward-looking standards to meet a request from a customer and their integrator, we helped to develop a product that will improve efficiency in the first solar installation in New Mexico and many more to come.”