When it comes to installing voice and data cabling, there is more to take into consideration than just performance – you also need to consider safety codes and standards. No business wants to spend thousands of dollars on cabling just to find out they used the wrong type in the wrong area and have to shell out more money to redo the work properly. Cat5 and Cat6 cables most commonly come with two types of jackets: CMR and CMP. Their safety ratings are defined by the NEC (National Electrical Code).
CMR (Communications Multipurpose Cable, Riser) should be used in riser closets between floors. This riser-rated cable is flame retardant and prevents the spread of fire between floors. It can be used anywhere except air returns. Be sure to seal all holes in walls and ceilings with a fire- retardant caulk or another fire stopping barrier.
CMP (Communications Multipurpose Cable, Plenum) must be used in any plenum space. This plenum-rated cable smokes less, burns cleaner and self-extinguishes easier. CMP is used in all air return spaces and this is why it’s an NEC code. The most common air returns are drop tile ceilings and raised floors. Raised floors are used quite often in server rooms. Not all drop tile ceilings are cold air returns but need to be checked out before cabling starts. Look for more than one air vent in each room.
After cabling is complete, it must be inspected by a city inspector and electrician to ensure the job is up to code. CMR is cheaper and more flexible but you need to bear in mind that in a fire it will produce a thick, dangerous smoke. The jacket of CMR is polyvinyl chloride (PVC). The jacket of CMP is fluorinated ethylene polymer (FEP). This makes CMP cable more expensive but it can be used anywhere that CMR can be used, but with the addition of air returns.
If you need to find the right cable and installer for your upcoming cabling project, contact us. Put our team’s knowledge to work for your business. Whether you’re planning a remodel, move, or build-out, we’ll get your voice and data cabling in the right place at the right time.
