NFPA664 220.127.116.11.4.1(1) (dust collector less than 5,000CFM) states: "connected directly to a listed spark extinguishing system.
NFPA664 18.104.22.168.4.2(1) (dust collector more than 5,000CFM) states: " equipped with a listed spark detection system" nothing is said about extinguishing. Is this an over sight? What is the intent? Does this assume a "listed spark detection system" includes extinguishment?