There are five basic types of Fire Alarm Cable that are identifiable by the areas where they are approved for use by the National Electric Code.

• FPL— Power Limited for general purposes. This designation indicates that this fire alarm cable is non-plenum rated, and may not be installed in risers, ducts, plenums, or other spaces used for environmental air unless first installed in conduit. Although FPL cables resist the spread of fire, they are not typically as fire-resistant as plenum and riser-rated cables.
• FPLR— Power Limited Suitable for the floor to floor, or “riser-rated.” Risers are the spaces that run vertically from floor to floor in a building. The National Electric Code requires FPLR cable to be fire-resistant to prevent fires from spreading through multiple floors of a building.
• FPLP— Power Limited Suitable for use in ducts, plenums, and other spaces dedicated to air circulation because of the extra safety features incorporated into its design. This Cable is plenum-rated, fire-resistant, and produces little smoke in the case of a fire.
• NPLF— Non-Power Limited for general purpose.
• NPLFP— Non-Power Limited Suitable for use in ducts, plenums, and other spaces.