What marking designates a power-limited fire alarm cable suitable for plenums?

The marking that designates a power-limited fire alarm cable suitable for plenums is FPLP. This specific designation indicates that the cable is designed for use in plenum spaces, which are areas utilized for air circulation in heating and air conditioning systems. Because plenums can be sensitive areas where fire and smoke could spread more easily, cables used in these environments must meet stringent flame-resistance criteria and low smoke emission standards.

The designation FPLP signifies that the cable is not only power-limited but also complies with the necessary safety standards for installation in these high-risk areas. It is crucial for cables used in plenums to have properties that reduce the risk of fire hazards and minimize the release of toxic smoke, which is fundamental for maintaining safety in commercial and residential buildings. Thus, when selecting cables for such environments, it is essential to look for this specific marking to ensure compliance with fire safety regulations.