Which of the following is an acceptable substitution for Class 3 Plenum cable (CL3P) in a power limited circuit?

Class 3 Plenum cable (CL3P) is specifically designed for use in plenum spaces, which are areas used for air circulation in heating and air conditioning systems. The core requirement for any substitution in a power-limited circuit is that the alternative cable must have suitable ratings for plenum applications and also meet the necessary fire safety standards.

CMP (Communications Multi-Purpose cable) is rated for use in plenum spaces and meets the stringent fire safety requirements necessary for these environments. This rating allows CMP cables to be used in areas that require enhanced fire resistance, making it an acceptable substitution for CL3P in power-limited circuits.

Other options, while they may have their own ratings, do not carry the same plenum designation or fire safety qualification needed for safe use in air handling spaces. For instance, CL2P could be used in applications where the cable will not be located in a plenum, while CL2R is designed for riser applications, and CM is the riser-rated cable that does not specifically meet the plenum requirements.