Confined Spaces Installation
For installations in occupied commercial and residential structures – or in passenger rail tunnels, pedestrian tunnels – there is a stringent requirement for duct and fiber cable products to be manufactured using plenum or Low Smoke Zero Halogen (LSZH) rated materials.
INSTALLING LSZH IN TUNNEL APPLICATIONS
Use the proper pulling hardware and do not exceed the maximum tensile pull rating of the ducts. Use swivels – attached to each duct and, the lead pull line – and wire rope slings (bridle) for maximum pulling clearance in the conduit and reduce twisting of the ducts. When placing different size ducts simultaneously, the pull tension maximum is limited to the duct with lowest published pull tension maximum. Note that when air jetting in cables, LSZH duct products may have lower than normal jetting pressure maximums due to the nature of the LSZH material.
PLACING OF PLENUM MICRODUCT UNDER RAISED FLOORING
When placing plenum in raised-floor environments, to reduce undulations, it is critical to provide frequent support for the bundle or bundles. 12-way and smaller bundles need supports approximately every three feet, larger bundles about every four feet.
Note that plenum 8.5/6mm MicroDucts have a slightly larger ID, thus require the use of airtight end caps versus tapered plugs for both inside and outside plant (ISP and OSP) applications.
