low voltage in same hole

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difowler1

Senior Member
Its an industry standard of course, not to install low voltage wiring in the same drilled hole through a wooden residential stud that contains standard electrical 120volt wiring. I would appreciate a hand with a code reference.
 

infinity

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If you have two cables in the same hole then no separation is required. The 2" dimension does not apply to power and "low voltage" cables.
 

gadfly56

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New Jersey
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Professional Engineer, Fire & Life Safety
If you have two cables in the same hole then no separation is required. The 2" dimension does not apply to power and "low voltage" cables.

Please see 725.136 (NEC 2011) Separation from Electric Light, Power, Class 1,
Non-Power-Limited Fire Alarm Circuit Conductors, and
Medium-Power Network-Powered Broadband Communications Cables


Look at (I). The OP's description of this "installation" doesn't appear to meet any of the exceptions (B) through (H). And before you jump on the liberal use of the word "conductors" in this section, note that (A) says "Cables and conductors..."
 

infinity

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Please see 725.136 (NEC 2011) Separation from Electric Light, Power, Class 1,
Non-Power-Limited Fire Alarm Circuit Conductors, and
Medium-Power Network-Powered Broadband Communications Cables


Look at (I). The OP's description of this "installation" doesn't appear to meet any of the exceptions (B) through (H). And before you jump on the liberal use of the word "conductors" in this section, note that (A) says "Cables and conductors..."


Are you saying that conductors and cables are the same thing?
 

John120/240

Senior Member
Location
Olathe, Kansas
Are you saying that conductors and cables are the same thing?

When I here "conductors" I automatically think of THHN, MTW, XXHW etc usually contained in a raceway of some sort. The word "cables" makes me think of Romex, cat 5, speaker wire etc. So In my opinion conductors & cables although similar are not the same thing. It is standard practice here to keep the two separated whether required or not.
 
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ActionDave

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What I'm saying is that the NEC is applying this criterion to BOTH cables and conductors.
None of this applies to a hole in a stud though.

725.136
(A) General. Cables and conductors of Class 2 and Class 3
circuits shall not be placed in any cable, cable tray, compart-
ment, enclosure, manhole, outlet box, device box, raceway,
or similar fitting with conductors of electric light, power,
Class 1, non?power-limited fire alarm circuits, and medium-
power network-powered broadband communications cir-
cuits unless permitted by 725.136(B) through (I).
 

gadfly56

Senior Member
Location
New Jersey
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Professional Engineer, Fire & Life Safety
None of this applies to a hole in a stud though.

It's true that the word "penetration" is absent, and it's presence would have nullified your objection. However, if you had a room in commercial construction (say) and you ran Class 1 and 2 or 3 through those punch-outs in the aluminum stud for a hundred feet or so, I'd opine that you've violated the intent of the section, if not the wording.
 

kwired

Electron manager
Location
NE Nebraska
I don't see that running a class 2 or a communications cable in close proximity to a 12-2 NM cable will have significantly difference in performance or safety then same LV/communication cable run same distance away from a pair of 12 AWG conductors enclosed in a PVC raceway. Many communications cables are either shielded or at least twisted pairs and that eliminates most interference that matters anyway.

Both the NM cable (as well as all other "power cables") and the Cl2 or communication cable are listed for stand alone installation (not required to be in a raceway). Type of occupancy or other situations may not allow some cables, but that is a whole different issue.

Some LV or communications equipment may recommend or even require more separation from lighting and power circuits/cables, but that is design issues beyond code minimums.
 
Its an industry standard of course, not to install low voltage wiring in the same drilled hole through a wooden residential stud that contains standard electrical 120volt wiring. I would appreciate a hand with a code reference.

Here you go:

800.133(A)(2) Communication wires and cables shall be separated at least 50 mm (2 in.) from conductors of any electric light, power, class 1, non-power limited fire alarm, or medium power network powered broadband communications circuits.

note this is for article 800 communication circuits. The term "low voltage" is pretty vague. Also note there is an exception for most common cables assemblies which basically makes the exception the rule and the rule the exception.....
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
800.133 (A)(2) Other Applications. Communications wires and cables
shall be separated at least 50 mm (2 in.) from conductors of
any electric light, power, Class 1, non-power-limited fire
alarm, or medium-power network-powered broadband
communications circuits.

Exception No. 1: Where either (i) all of the conductors (~l
the electric light, powel; Class i, non-power-limited fire
alarm, and mediw11.-power network-pmvered broadband
communications circuits are in a raceway or in metal-
sheathed, metal-clad, nonmetallic-sheathed, Type AC, or
Type UF cables, or (2) oll of the conductors ql communi-
catiolls circuits are encased in raceway.


This is repeated in 820.133 , 830.133 (840.133 refers to 770.133) , etc etc.....

~RJ~
 

difowler1

Senior Member
class types

class types

It's true that the word "penetration" is absent, and it's presence would have nullified your objection. However, if you had a room in commercial construction (say) and you ran Class 1 and 2 or 3 through those punch-outs in the aluminum stud for a hundred feet or so, I'd opine that you've violated the intent of the section, if not the wording.

are the wire and cable classes listed in one place in the code book.

I was saying "low voltage" wires. The wires installed through the same holes are coaxial, cat5, cat6, a red alarm wire, and a blue (I imagine) security wire.
 

tom baker

First Chief Moderator
Staff member
800.133 (A)(2)
This is repeated in 820.133 , 830.133 (840.133 refers to 770.133) , etc etc.....

~RJ~


But 800.133 is for wires and cables attached to the outside of the building,
800.133 (A)(2) is for inside, separation for conductors not cables.
If you can accept that a cat 5 cable can run along side a RMC, then a cat 5 cable is allowed along side a NM cable. the NM and RMC are both chapter 3 wiring methods
 
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