Automated control cables and raceways

[shputnik]

I have a question regarding raceways and control cables being pulled inside of them. Is there a limit on how many low voltage cables for automated control that can be installed in a raceway besides cubic inches fill? Where would I find that in the code book? Article 725? I have seen raceways with both shielded and regular cables 18/2, 18/6 and such. For the numerous control devices of an HVAC system going out to the devices and back to the control cabinet.

It seems like the common way but my question is if it's the correct way and where would I research that?

Is the low voltage aspect of fire alarm (from the low voltage side of the fire alarm module back to the control cabinet) allowed to be in the same raceway as the other control components cables

 

[petersonra]

Article 725 is your friend. Some of these conductors may be Class 1, others Class 2.

For Class 1, take a look at 725.48 and 725.49.

For Class 2, see 725.133, 725.136 and 725.139.

 

[don_resqcapt19]

The wire/cable fill answer for any Article 725 installation is found in 725.3(A), which sends you to the generic wire fill rule for raceways in 300.17.

For the fire alarm cable question, see 760.139. Wire fill for fire alarm wire/cable is in 760.3(J) which also sends you back to 300.17.

The fill is always based on the area of the conductors and or cables and the area of the raceway. In most cases you are limited to a 40% fill.

For the fill calculations for cables, you will have to consult the manufacturer's data sheet to find the diameter and calculate the area, or, if provided, use the area in the manufacturer's data sheet.