Hello group,

I'm on a job where I need help with the fire smoke dampers.wondering how these work, I'm new to the dampers. Power open, just wondering how these work. Know nothing!!!!! They have 2 sets of FSD Honeywell #ML4115 b 1008 and the other is a greenheck with tb2000 actuator. 2 different sets of dampers, have they already been replaced before. There having issues of them closing. Looking for a 101 on FSD. Thanks group