phone and power in the same conduit

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Lady Engineer

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New Jersey
jeff1166 said:
Can you tell me the code reference to this question? Is it legal to run phone and power in the same conduit?

No, and they can not be in the same pull box. Unless there's suitable divider in the conduit or pull box, no.


Lady :)
 

oldguy

Member
phone & power in same conduit

phone & power in same conduit

after you get done with 800.133, consider this...

if you're supplying phone wiring to old black desk phone, you'll probably be okay. if you're supplying any kind of new 'phone, you're customer is most likely to end up with noisy connection.

best bet is to keep low voltage wiring far away from line voltage wiring, except when they cross at 90 degree angle.
 

infinity

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jeff1166 said:
Can you tell me the code reference to this question? Is it legal to run phone and power in the same conduit?


Depends on if the power conductors are in a cable or not. A piece of NM cable and a phone cable are permitted in the same raceway.
 

kbsparky

Senior Member
Location
Delmarva, USA
They bury them in the same trench all the time. Power company routinely drops phone cable in when they run the power secondarys to individual houses.



Can anyone tell me what the difference is if they happen to be in the same raceway? Note: I am not disputing anything here WRT whether this is permissible or prohibited in the Code. Just pointing out actual field practice of the utilities.

One more thing to add to this discussion: One local utility here is using a "quad" cable assembly on their new underground service installs. That 4th "wire" is actually fiber optic, and they install a separate box next to the meter box for future use; I believe that they are planning to sell phone, TV and internet service once they get their infrastructure in place.

That should get the present cable company shakin' in their boots ... and I can't wait
 

infinity

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don_resqcapt19 said:
Trevor,

Code section?
Don

I can't. But I can't find a prohibition either. Closest thing I see is 800.133(A)(1)(c) which prohibits conductors together but does not restrict cables.
 

don_resqcapt19

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Trevor,
I don't agree that there is a difference between cables and conductors in 800.133(A)(1)(c).
Don
 

al hildenbrand

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Location
Minnesota
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Electrical Contractor, Electrical Consultant, Electrical Engineer
If the cables contain conductors, then by putting the cables in close proximity, the conductors are in close proximity.

Whether the conductors are in a package identifiable as a "cable", or not, if the cables are together, power and comm, in the same raceway, the conductors are together in the raceway.
 

infinity

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Cables and conductors are not the same thing. Here is the Article 334 definition of an NM cable:

334.2 Definitions.
Nonmetallic-Sheathed Cable. A factory assembly of two or more insulated conductors enclosed within an overall nonmetallic jacket.

Doesn't sound the same as a conductor to me.
 

dduffee260

Senior Member
Location
Texas
How do they install lighting and communications in an elevator? Aren't these two voltages in close proximity? Is the cable rated in a special way? Is all the voltage low or something like that? I am talking about the long cable type not the hydraulic piston type.
 

al hildenbrand

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Location
Minnesota
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The Op is:
Is it legal to run phone and power in the same conduit?
Trevor, if both the phone cable and the NM cable had no conductors in it. . .then fine, . . . put the cables together in an raceway. . .

800.133(A)(1)(c) simply says "conductors". . .if there is an assembly of conductors in a "cable", there are still conductors there that are called conductors. . .witness the NM definition you cite using the word "conductors".

If a cable, containing conductors, is placed together in a raceway with loose communication conductors or communication conductors in a cable assembly, those conductors, whether in a cable or not, are together in a single raceway.
800.133 Installation of Communications Wires, Cables, and Equipment
(A) Separation from Other Conductors
(1) In Raceways, Boxes,and Cables

(c) Electric Light, Power, Class 1, Non–Power-Limited Fire Alarm, and Medium Power Network-Powered Broadband Communications Circuits in Raceways, Compartments, and Boxes. Communications conductors shall not be placed in any raceway, compartment, outlet box, junction box, or similar fitting with conductors of electric light, power, Class 1, non–power-limited fire alarm, or medium power network-powered broadband communications circuits.
 
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infinity

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al hildenbrand said:
The Op is: Trevor, if both the phone cable and the NM cable had no conductors in it. . .then fine, . . . put the cables together in an raceway. . .

800.133(A)(1)(c) simply says "conductors". . .if there is an assembly of conductors in a "cable", there are still conductors there that are called conductors. . .witness the NM definition you cite using the word "conductors".

If a cable, containing conductors, is placed together in a raceway with loose communication conductors or communication conductors in a cable assembly, those conductors, whether in a cable or not, are together in a single raceway.


I'm still not convinced. THHN and a phone cable in a conduit is prohibited, not two cables if one is a power cable and the other a phone cable. Are you also saying that a phone cable and a piece of NM cannot be installed within the same bored hole through a stud?
 

al hildenbrand

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Minnesota
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Electrical Contractor, Electrical Consultant, Electrical Engineer
infinity said:
THHN and a phone cable in a conduit is prohibited
Why do you understand that to be so? By your statements above, the phone cable is a cable. . .it is not conductors.
 

infinity

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al hildenbrand said:
I don't understand a bored hole in a stud to be a raceway.

You didn't answer the question. If cables and conductors are the same thing (your opinion) than according to 800.133(A)(2) you would need 2" of separation between the NM and the phone cable. Therefore they could not be in the same hole or even attached to the same stud for that matter.
 

infinity

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al hildenbrand said:
Why do you understand that to be so? By your statements above, the phone cable is a cable. . .it is not conductors.

But the THHN is conductors. Stick them in a jacket and you make a cable. Now they're OK together.
 

al hildenbrand

Senior Member
Location
Minnesota
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Electrical Contractor, Electrical Consultant, Electrical Engineer
infinity said:
Are you also saying that a phone cable and a piece of NM cannot be installed within the same bored hole through a stud?
infinity said:
You didn't answer the question.
Huh?

Sure I did. I just didn't answer what you thought you were asking.

I'm staying with the OP and 800.133(A)(1)(c), that is, raceways.

infinity said:
But the THHN is conductors.
Sure they're conductors. But by your logic, the phone conductors in a cable are a cable and therefore the phone cable is not a conductor and must be OK with THHN in a raceway.
 
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