What is the function of a Fire Department Connection (FDC) in a sprinkler system?

• A. Local alarm only
• B. Controls building HVAC
• C. Detects smoke
• D. External point for firefighters to connect water to augment the building’s supply

Answer: (D)

The function of an FDC is to provide an external connection point for firefighters to pump water into the building’s sprinkler or standpipe system, augmenting the building’s water supply when needed. This external hookup lets a fire department pumper deliver additional flow to reach the demands of a fire, especially if the building’s own supply or pumps aren’t enough. It’s not a smoke detector, HVAC control, or alarm trigger—those systems are handled elsewhere. Typically located outside the building with large-diameter connections, the FDC is where firefighters connect hoses to boost the sprinkler system’s supply to fight the fire.