Like copper cords, the NEC (National Electrical Code) requires that fiber optic cables be fitted with fire and smoke. NEC stipulates that all indoor fiber cables must be properly marked and appropriately fitted to their intended use.
According to NEC, the interior area of the building consists of three parts: plenums, risers and general purpose areas
:: Mi the Plenum area?
The Plenum area is a building area that is used for air flow or air distribution systems. In most buildings there is air return (air source) for air conditioning under the floor surface or raised floor. Flooded ceilings and raised floors are also available where fiber cables are installed. If these cables burn, they give toxic fumes and smoke from the air conditioner to the rest of the building. As a result, people can be injured, even if they are far from the fire.
:: What's the Riser Area?
The Riser area is a floor opening, shaft, or canal that runs vertically through one or more floors
:: What is the general purpose area?
All areas that are not plenum or take off and are on the same level as a general purpose area.
: Fiber Optic Cable Fire & Smoking Marking
OFNP is the Optical Fiber Nonconductive Plenum. The OFNP cables are fire resistant and have low smoke generation characteristics. They can be installed in ducts, plenums and other spaces for ducting. This is the highest fire wire cable and other cable types can not be replaced.
OFCP stands for Optical Fiber Conductive Plenum. The OFCP cables have the same fire and smoke as the OFNP cables, but have a lead armor or middle strength member, usually steel. The OFCP cables must be earthed on both ends. As a result, OFCP cables can not be installed in the same cable tray or wiring as the power cables.
The OFNR is a non-leader of optical fibers. The OFNR cables are used in Riser areas that build vertical axes or run from floor to floor. The OFNR cables can not be installed in plenum areas as they do not have the necessary fire and smoke as Plenum certified cables. The OFNP plenum cables can be used as substitutes for OFNR cables
OFCR is an Optical Fiber Conductive Riser. OFCR cables have the same fire resistance characteristics as the OFNR cables but have a conductive armor or middle strength member, usually steel. The OFCR cables must be earthed on both ends. OFCP cables may be replaced by the OFCR cable. OFCR cables can not be installed in the same cable trays or cable ducts as power cords.
OFNG is not general purpose for optical fibers. Typically used for horizontal wiring, single-level applications. The OFNG cables can not be used in plenums or hoists. OFNP and OFNR cables can be used as a substitute for OFNG cables
OFCG is an optical fiber guide for general purpose purposes. The OFNG cables have the same fire detection features but have conductive armor or core strength members typically made of steel. The OFCG cables must be earthed on both ends. Do not install in the same cable tray or wiring as the power cord.