Can FPL cables be used for general purpose alarms without conduit? If yes, are there any exceptions?

Using FPL (Fire Power-Limited) cables for general-purpose alarms without conduit is permissible under certain conditions. Specifically, the exceptions mentioned pertain to riser, duct, and plenum applications, which are critical areas where enhanced fire safety protocols are mandated by electrical codes and standards.

In riser applications, where cables run vertically between floors, it's vital to meet fire safety requirements to protect against the spread of flames. Duct systems, often used for HVAC or similar purposes, can also pose risks if the electrical cabling is not appropriately rated or protected. Plenum spaces, which are used for air circulation in heating and air conditioning systems, are especially sensitive environments due to their potential to facilitate the rapid spread of smoke and fire.

Therefore, while FPL cables can indeed be used in non-conduit applications, this usage is contingent upon the specific environments they are installed in. The outlined exceptions ensure adherence to safety standards while allowing for some flexibility in installations where conduit might not be feasible.