Proper Application of Panelboards in Solar Arrays - Data Bulletin

Panelboards are designed, tested, and certified to meet the requirements of Underwriters Laboratories (UL) 67 Standard for Panelboards, while molded case circuit breakers are required to meet UL 489 Standard for Molded Case Circuit Breakers. These governing standards define the maximum ambient design temperature of the equipment to be 40°C (104°F). Equipment that is certified under these standards must operate properly when tested under laboratory conditions at the ambient temperature ranges defined in them. Schneider Electric recognizes that in certain applications, such as solar (PV or photovoltaic) fields, the equipment is applied in environmental conditions that are typically more severe than the governing standards that they were designed under. It is the responsibility of the engineer of record to properly select and apply equipment in the field. The purpose of this document is to define the proper considerations to be taken into account for reliable equipment operation.