Riser, Plenum, Direct Burial Cable - Which Cable Should I use? 


The Riser Cable (CMR, CL3R, CL2R, FPLR, CATVR), as its name implies, is used primarily for risers and other vertical shafts during cable installation. The jacket on these cables is designed to prevent the spread of fire from floor to floor- definitely not something you want to have skimped out on in the unfortunate event of a fire in your home or business. 


The Plenum Cable (CMP, CL3P, CL2P, FPLP, CATVP) is rated for the “plenum spaces” in buildings, which are simply the parts of the building that facilitate air circulation in heating and air conditioning systems. Plenum cable is covered in fire-retardant and low-smoke plastics, in the hopes of slowing the spread of fire and smoke to the living spaces in the building. CMP cable meets all the requirements for CMR cable and can therefore be used in risers, but CMR cable can’t be installed in the plenum spaces. 


General Purpose (CM, CMG, CL3, CL2, FPL, CATV) cable is simply a general-purpose cable that can be used in installations not limited to the use of CMR and CMP cable. They are still fire-retardant, but don’t meet the strict requirements of either of the previous cables. Typically, CMG cables are used in most home cable installations. 


Direct Buried Cable is not regulated by the NEC or the NFPA at all. This designation simply means that the cable has been engineered to be buried without any kind of outside protection. It is built to be more resistant to temperature changes, moisture, crushing as well as other environmental factors.  


Outdoor Cable (Sunlight Resistant Cable) - also informally known as UV Rated Cable, it could be installed in locations exposed to sunlight. A sunlight resistant cable means that a cable has been evaluated for long-term exposure to damaging UV light. The Outdoor Cables are designed to be used outdoor, but they are not recommended for direct burial unless a conduit is used. 


Have More Questions? 

Have more questions that we haven’t covered here? Please feel free to reach out to us!  

Alpha Cable has a variety of riser-rated and plenum-rated cables perfect to suit any installation. Check out our website or contact us for more information.