Which cable type is required when Class 2 circuits go vertically through more than one floor?

The appropriate cable type for Class 2 circuits that travel vertically through multiple floors is CL2R. This designation signifies that the cable is rated for riser applications, meaning it is designed for vertical spaces where cables run between floors. Riser-rated cables have a fire-resistant jacket that helps contain flames and prevent them from spreading between floors, which is crucial in multi-story buildings.

While there are other Class 2 cable types, they do not meet the specific requirements for riser applications. For example, CL2P is intended for plenum spaces, which are areas used for air circulation in heating and air conditioning systems; it is not suitable for vertical installations as it does not have the same fire safety characteristics for riser applications. CL2X and CL2D are designed for other purposes and do not carry the riser designation, which is essential for ensuring compliance with safety codes in buildings where Class 2 circuits will pass through different floors.

Therefore, selecting CL2R ensures that construction meets building code requirements for fire safety and prevents the potential risk of fire spreading vertically within the structure.