Override Installations
For underground duct and conduit that is at or near capacity with installed cables, an alternative to removing cables in order to free up conduit space is to utilize the extra space by overriding the existing cable in the conduit with MicroDucts.
OVERRIDE PULL-IN METHOD FOR OLD CONDUIT SYSTEMS
When larger, older conduits – such as PVC and terra cotta types – are occupied with one or more cables but have sufficient space to house additional MicroDucts, then individual or bundled MicroDucts can be pulled in using conventional rodding processes in conjunction with pull ropes or tapes to increase the cable density capacity of the occupied duct or conduit. A pulling swivel and staggered wire bridle sling are attached to self-threading pulling eyes are connected to each individual MicroDuct.
AIR-JETTED INSTALLATION METHOD
In situations where typically 2” and smaller HDPE conduit housing a single optical fiber cable are involved, one or more appropriately sized MicroDucts can be air-jetted into the occupied duct using a specialized Y-Block Adapter to isolate and seal off the current cable in the duct. Then, the additional MicroDuct(s) can be placed in the duct using compressed air and tractor type air-jetting equipment fitted with multi-groove belts to install multiple MicroDucts. When simultaneously installing more than one MicroDuct, it is important that the MicroDuct ends are free and not joined or connected together.
