A guide to help figure out how many cables you can pull through a hole to help you plan your structured wiring project.
I’d like to run new cables for TV, phone and network and I came up with this little chart that might help you figure out how many telecom cables you can pull through a hole. It includes Cat3 2-pair, Cat3 4-pair, Cat5 4-pair, Cat5e 4-pair, Cat6 4-pair, RG59 and RG6 Quad Shield in various sized holes.
Dimensions of cables vary so please double check the actual cables you’re going to use.
For the holes I selected sizes that match the auger sizes of Greenlee D’Versibit Flexible Drill Bits which are a popular type of installation bit used when pulling cables in existing walls. The bits come in 3/8″, 1/2″, 9/16″, 3/4″ and 1″ diameters.
There are 2 values in the chart. In black is the maximum number of cables I think I can jam through the hole and in green is the number of cables based on a 40% fill.
The NEC (National Electric Code) specifies conduits for power cables should not exceed 40% fill. This allows for some room to run extra cable in the future or change to larger cable as well as heat and providing enough room to minimize chances of damaging cables while pulling.
For some reason TIA/EIT and most LAN installers have adopted the 40% fill rule even though these are very lower power cables. When running cable through conduit the NEC says that the same conduit fill rules apply for low power cables as I understand it. I’m not 100% sure what the rule is when just running cable through holes and not conduit. What I’ve seen installers do is measure the size of their cable bundle and choose a drill bit slightly larger so that the bundle pulls easily without damaging the cable. The hole size needs to conform with building codes regarding making holes in structural members (generally no more than 1/3rd the width of the member.) Check with your local codes before starting. This is used mainly as a guide to help in planning and determining which size bits to buy. They aren’t cheap!
As you can see the Cat6 cable is a lot thicker than Cat5e cable. The whole reason I made this chart was to determine which cable to buy as I have a limited amount of space to run the cables.
They both support Gigabit Ethernet 1000Base-T. Even the older Cat5 cable was able to run at gigabit speeds. The issue comes with transmission problems that may cause errors and slow down the network. Cat5e is better than Cat5 and Cat 6 is better than Cat5e in that regard.
Most Cat6 cable has a plastic center spline that helps prevent crosstalk and other signal issues. That’s the main reason the Cat6 cable is thicker. Some manufacturers have found ways to make cable that meets that Cat6 spec without the need for the center spline.
Most of the splineless cat6 cable I’ve seen is plenum rated. (see Cat6, Splineless, UTP, 23AWG, 8C Solid Bare Copper, Plenum, 1000ft, Blue, Bulk Ethernet Cable (Made in USA)) which is about 3 times the cost of regular riser cat 6 with a spline. The plenum rating means it’s made with a different jacket material that doesn’t release toxic fumes if it burns. I did however find this Riser rated ICC CMR CAT6 UTP 500 MHz (NO SPLINE) / ICC-ICCABR6VWH which is only 2x the cost of regular Cat6 cable.
If I use Cat5e or splineless Cat6 the installation will be easier as I’d have to drill less holes or I could make smaller holes. Still trying to figure out if it’s worth the expense of the more expensive splineless Cat6 instead of regular Cat5e.