An Overview Of Bulk Plenum CableTo establish an enterprise-based computer network in a large building equipped with a central air conditioning system, bulk plenum cable is used. Bulk here means large quantity and cable here refers to standard networking cable in this specific context made of shielded and insulated solid copper wires. The word plenum literally refers to an air circulation space. In this particular context the word specifies that the cable would be routed through the air conditioning ducts between the actual and the false ceiling of the building. These air flow ducts circulate air that is rich in oxygen. Because of the rich oxygen content these ducts are highly susceptible to the promotion of fire hazard and therefore materials used in them must necessarily be fire and smoke resistant. ASHRAE (American Society of Heating, Refrigeration, and Air Conditioning Engineers) standards therefore require that any materials used in air conditioning ducts must be resistant to fire and produce low smoke when exposed to a fire. Therefore, bulk plenum cable is required to conform to NFPA (National Fire Protection Association) standard 262 in view of the fact that it is routed through air conditioning ducts. To make it conform to these standards, bulk plenum cable uses wire insulation of expensive Teflon material. Teflon is highly resistant to fire and especially smoke production. It is due to this reason that the price of plenum cable is more than that of non-plenum cable which uses PVC (polyvinyl chloride) insulation. Moreover, because of the high risk of fire in an air conditioning duct, high voltage power cable rated above 50 volts is not allowed to be routed through it. In contrast, bulk plenum cable is allowed since its voltage rating is below 50 volts. However, the storage of bundles of abandoned plenum cables or new plenum cable spools is not allowed in these spaces exposed to fire risk. Plenum cables used in large enterprises must be capable of carrying data without appreciable loss. Solid copper wire conductor cables can do so more readily than stranded copper conductor wire cables. Therefore, bulk plenum cables used for the purpose use solid copper conductors. However, solid wire has much lower bend radius for routing in comparison with stranded wire. The latter can be bent easily because of their high flexibility. Cable bend radius affects routing and therefore bulk plenum cables routed through air conditioning ducts have to be necessarily fixed-in-place installations. Moreover, these spaces are normally not opened or frequented except for maintenance work. So, fixed-in-place installation of solid copper conductor bulk plenum cable is eminently suitable for such routing without data loss. Plenum cable used today for networking consists mostly of either category 5e (CAT5e) or category 6 (CAT6) solid copper wire conductor. Lately, we are now hearing of the advent in future of the even more expensive CAT7 solid copper wire conductor bulk plenum cable. Its standard is currently under preparation and is expected to be released somewhere in the year 2013. |