Conduit Capacities

[dhennen]

We're building a new house. I running conduit for future expansion of a security system and whole house audio, but am having trouble finding the typical outside diameter of various cables to determine what size conduit I need.

I am running conduit for:

SPEAKERS

For many rooms I will have two speakers in each. I will run conduit to the first speaker than on to the second. So part of the run must be able to hold two 2-conductor 12 AWG speaker cables. Is a 3/4" conduit large enough for this?

MOTION SENSORS AND VIDEO CAMERAS

I know I need 2-conductor 18 AWG for power, 2 or 4-conductor 22 AWG for the motion sensor, and will likely use some extra CAT-5e + baluns for the video camera, if I dont use an IP camera. Is a 3/4" conduit large enough to fit these wires?


In future keypad locations I will put 1" conduit.

To head off other questions: I'm running coax + several CAT-6 to at least 2 outlets in most rooms, as well as empty 1" conduit. I'll also be hard-wiring door and window sensors.

 

[Del91574]

The best answer, especially since you're dealing with new construction would be to pick up a copy of the NEC that is enforced in your municipality, because conduit fill and sizing would be addressed in the tables within. I personally wouldn't waste the effort to run pipe for speakers unless construction dictated it was absolutely needed, but to each their own.

a 3/4" pipe (EMT) would be appropriate for a motion/camera wiring combo as dictated by your basic wiring specs. If you're planning on a different sort of raceway, then I'd base it off the tables in the NEC. If you're going through the effort of putting in a raceway at 2 outlets per room, then I wouldn't go through the effort of putting in the wiring to begin with, since your conduit would facilitate pulling whatever you feel like to each location afterwards, otherwise I'd pull a structured cable with fiber inside to each location.

 

[mikejrc]

the conduit and box fills in the NEC dont apply to some types of low voltage applications, the tables apply to listed types of electrical cables/conductors.

There are differences between the NEC and the TIA standards. TIA standards seem to be a little more strict than the National Electrical Code.
in your case the TIA 570-B standard applies to residential, the article in the link below applies to 569 commercial standard, but it will give you a good reference point to start.

http://www.lanshack....onduitRuns.aspx

 

[Del91574]

the conduit and box fills in the NEC dont apply to some types of low voltage applications, the tables apply to listed types of electrical cables/conductors.

There are differences between the NEC and the TIA standards. TIA standards seem to be a little more strict than the National Electrical Code.
in your case the TIA 570-B standard applies to residential, the article in the link below applies to 569 commercial standard, but it will give you a good reference point to start.

http://www.lanshack....onduitRuns.aspx

I'm sorry, but your post is contradicting, the NEC applies to all electrical installations, and honestly, fill does apply, however it is modified in it's format for a cable assembly vs. individual conductors.

Right out of the first paragraph listed on your link:

Before we start to discuss the differences between the EIA/TIA-569 (Commercial Building Standard for Telecommunications Pathways and Spaces) and the National Electrical Code (herein referred to as “NEC” or “the code”), as they pertain to conduit installations, let’s keep in mind, the fact that the NEC is the law of the land, and the EIA/TIA-569 is a recommended standard.

The NEC does however specify conduit fill and a FPN regarding fill vs circular mils (diameter of cables) including the percentage of fill. EIA/TIA is merely an advisory for recommended "best practices" within the industries.

 

[Neurorad]

No need for conduit to speaker locations. You'll never need to replace the speaker cables. Ditto for contact sensors - when a nail goes through a cable 10 years from now, you'll use wireless for that zone.

Install the conduit empty, run the cables next to the conduit.

If you KNOW you'll need a cable, install it now.

Conduit for attic to basement runs, and for video display locations.

 

[mikejrc]

When it comes to low voltage NEC codes are not clear from a practical point of view. Thats the article's point, the NEC doesnt specify certain things when it comes to low voltage leaving you dealing with the exceptions part of it. There are not specific references to CAT wire as opposed to electrical wires.

third paragraph states: If you ever read through the NEC, you will notice that along with almost every rule, there will be a list of exceptions to the rule. The exceptions recognize the fact that these installations are done in the real world. There are many instances where a rule may not apply, or not be practical, or may make certain installations impossible to do.

ex. we had cat 6 runs failing the fluke test, runs were close to 260 feet. the NEC states no more than 360 degrees in a conduit run. The TIA says no more than 180 degrees per 100 feet. After re-pulling the wires 3 times and not passing the fluke test we decided to break the conduit run in 3 sections each with less than 180 degrees in total bend. that' s when we passed the fluke test.

ex. NEC article 800.110 Raceways for Communications Wires and Cables within buildings: Where communications wires and cables are installed in a raceway, the raceway shall be either of a type permitted in Chapter 3 and installed in accordance with Chapter 3 or a listed nonmetallic raceway complying with 800.182, and installed in accordance with 362.24 through 362.56, where the requirements applicable to electrical nonmetallic tubing apply.
Exception: Conduit fill restrictions shall not apply.


and yes i know the example stated above has nothing to do with the original post, but just to illustrate the facts in the article in question.
my suggestion to the original post, before he starts looking into all these technicalities to ask his AHJ, when it comes to his low voltage, if the NEC is god or TIA standards suffice.

If NEC is mandatory then he will have to look at the article i linked as a reference so he can deal with some of the calculations involved. Keeping in mind the calculations were made for EMT conduit. He would have to look in table 4 chapter 9 to match whatever conduit he will be installing.