conduit fill for low voltage cables

[Jim60004]

What is the allowable conduit fill percentage if I am running multiple low voltage (12V DC) and low current (no individual wire will have more than 40 milliamps) cables. I assume that the 40 percent fill for multiple wires is for heat build-up, which in my case will be none. My cables are 61 conductor/ 20 gauge.

 

[tthh]

For what you are doing, pulling the cable is through the conduit is more of a concern than anything else. Lower fill will make it easier to pull.

 

[don_resqcapt19]

If this installation is covered by Article 725, the 40% wire fill is a code rule as 725.3 references 300.17.

One low voltage cable that I installed for controls on an industrial product had instructions that specified no more than 30% fill, and no more than 150' between pull pull points with a 30' deduction for each 90. Often they also specify a maximum pulling tension. Most of the CAT5e cable I installed said no more than 25 pounds of pulling tension.

For low voltage cable, the real issue is, as was said in the previous post, physical damage to the cable and its conductors.