Fire tests in ventilated rooms extinguishment of fire in grouped cable trays

The purpose of the work was to determine the required automatic sprinkler design density necessary to extinguish a developing fire in a grouped cable tray installation. Four preliminary tests and four extinguishment tests using PE/PVC cable were conducted within a specially designed, ventilated room. The results showed that an average design of approximately 0.20 mm/s (0.30 gpm/sq ft 2) discharged from automatic sprinklers with a 13-mm (1/2-in) orifice, 71 C (160 F) temperature rating and 3.05-m x 3.05-m (10-ft x 10-ft) spacing provided successful extinguishment for the specific grouped cable tray fires investigated. The results also provided data on a case where a developing fire in a grouped cable tray installation did not open any of the installed standard sensitivity sprinklers, suggesting another parameter (i.e., higher sensitivity sprinklers) in need of attention.