Plenum (CMP) Vs. Riser (CMR) Cable Types for Cat5 riser cables and Cat 6 riser cables
Plenum Cables CMP is a cable that is installed in the vacant spaces in the walls or ceiling of the building. Usually in this case there are no temperature moderators in the plenum spaces and there is more chance of wires to get fire after getting heat.
The plenum spacing in the buildings is commonly used for wires to facilitate the networking system but it is extremely dangerous. Due to high temperature the wires catch fire and the air flow in the plenum spaces helps fire to get fresh oxygen and works as oil on fire.
In addition to that high voltage equipment is not helpful to install in the plenum spaces because of temperature obviously. If a little spark happens the equipment will get fire due to fresh pass of oxygen.
In USA, the jacket of plenum cables are tested under the authority of the National Fire Protection Association standard NFPA 90A (Standard for the Installation of Air Conditioning and Ventilating Systems).
Plenum cables are covered with a fire resistant plastic jacket of a low smoke polyvinyl chloride (PVC).
Polyolefin is basically based on polyethylene compounding. Efforts on non halogen plenum compound were made in 2007 citing new fire resistant synergist packages that provide an answer for our questions but under developed plenum cable marketed outside the United States.
All the stuff that is going to be used in making of the plenum cable is going to be tested to meet the standards with NFPA 262 and outlined in NFPA 90A accordingly.
Here you have to keep that in mind that a survey is done to check the standard of the non plenum air space. Its air space can be accidently become a plenum air space if ductwork is Plenum (CMP) Vs. Riser (CMR) Cable Types for Cat 5 and Cat 6 are disconnected or not properly repaired.
Ductwork detachment can happen due to building damage such as earthquakes; aging or adverse environment can result in the metal to corrode and fall apart, or simply carelessness on the part of building contractors that leave work undone.
In all these cases, discovery and repairing of such problems to eradicate unwanted plenums is difficult due to the hidden nature, limited space, and difficult access of most installed drop ceilings. For highest fire safety it is best to presume all drop ceiling airspaces are plenums, whether or not they are officially chosen as one.
Riser Cable CMR or sometimes referred to as PVC
You have to note that not all PVC Cable is essentially Riser rated cable which is to be run between floors in non plenum areas is rated as RISER cable.
The fire necessities on riser cable are not as strict. So, plenum cable can always substitute riser cable, but riser cable cannot substitute plenum cable in plenum spaces. Twisted pair, coaxial, HDMI and DVI versions of cable are made in plenum and riser versions.
In year 2006, important concerned developed occurred over the potential toxicity of FEP and related
Fluor chemicals including the process aid perfluorooctanoic acid (PFOA) or C8 such that California has projected some of these materials as potential human carcinogens.
The NFPA Technical Committee on Air Conditioning, in response to public comment, has referred the issue of toxicity of cabling stuff to the NFPA Committee on Toxicity for review before 2008.
In year 2007, a development plan specially targeting the manufacturing of a non halogen plenum cable complex was announced to specifically address lasting toxicity alarms presented by halogenated compounds for use in European and other global markets.