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

The correct answer is CMP (Communications Multipurpose Plenum). CMP cable is specifically designed for use in plenum spaces, which are often found in buildings between the structural ceiling and the dropped ceiling or under the floor. These areas are critical because they typically facilitate air circulation for heating and ventilation systems.

A key aspect of CMP cable is its high fire resistance and low smoke production, which aligns with the requirements for cables used in plenum spaces to ensure safety in the event of a fire. By substituting CL3P cable with CMP cable in power-limited circuits within plenum spaces, you maintain compliance with safety standards, as CMP is rated for use in these sensitive environments.

In contrast, while other cable types such as CMR (Communications Multipurpose Riser), CMX (Communications Multipurpose Exposed), and CMG (Communications Multipurpose General) have their own specific applications and ratings, they do not meet the necessary fire safety protocols required for installation in plenum areas. CMR is intended for vertical spaces between floors, CMX is suitable for exposed runs in non-plenum areas, and CMG is used for general applications where the highest fire resistance is not a requirement. Therefore, these options would not be acceptable