CommScope ConQuest Conduit Construction - Manual (Page 41)

Pulling Cable into Conduit 5.3
Fill Percentage
Fill Percentage
The fill percentage, sometimes referred to as fill ratio, is the amount of space that cable(s) occupy inside the conduit as
a percentage of the inner diameter of the conduit.
The greater the fill percentage the higher the sidewall pressure will be. This is critical when constructing the conduit run.
Bends should be made more gradual when fill percentages are high. ConQuest Cable In Conduit products are typically
designed not to exceed 30% fill. Recommended practices suggest that fill percentages should be at or below 60%.
Multiple Cables
It is preferred for each cable to have its own conduit, though often multiple cables must be placed in a single conduit.
Installing multiple cables or installing a single cable in a conduit with existing cables requires some special planning.
Recommended practices suggest that multiple cables be pulled together.
The fill percentage must be considered to ensure that there will be room enough for all of the cables, particularly in the
bends. NOTE: Refer to Fill Percent Calculation Table in the Appendix.
Another important consideration is the configuration of the cable in the conduit. There are two defined configurations
for multiple cables, triangular or cradled.
A cable configuration is considered triangular when the
conductors maintain a triangular pattern in the conduit. A
cradled configuration is when the cable has a random lay
in the duct and is preferred.
The cradle configuration will permit for higher fill percentages
and lower pulling tensions. A pulling harness should be
used when multiple cables are pulled in together. A swivel
should be used to connect the pull rope to the harness and
each cable should be connected to the harness with its
own breakaway swivel. This method will prevent triangular
configurations.
The lowest maximum pulling tension value of the cables being installed should be used in pull tension calculations being
made for multiple cable installations.
Conduit
Cables
Triangular
Configuration
Cradled
Configuration