Telephone Lines in Conduit

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twada

Member
Are telephone lines required to be installed inside the conduits? If so, where in NEC states that? The existing building I am working on has exposed telephone lines attached to interior walls with staples. Is it allowed?
 

tom baker

First Chief Moderator & NEC Expert
Staff member
Location
Bremerton, Washington
Occupation
Master Electrician
Re: Telephone Lines in Conduit

See Article 800. There is little danger of shock or fire from telecom wiring, conduit is not typically required. Also if its ahead of the network interface the wiring belongs to the Telco.
 

jhines

Member
Re: Telephone Lines in Conduit

See NEC article 800 for telephone wires.Telephone and data wiring is often not run in conduit. NEC 800.48 states that where communications wires are installed in conduit that chapter 3 applies. Article 800.49 requires cables to meet fire resistance standards. NFPA 72 for fire alarm does not require conduit for telephone wires connecting to a communicator.
 

jerryb

Senior Member
Re: Telephone Lines in Conduit

The voltage and shock hazard is not always the reason for putting something into conduit. If the HVAC system has ducted returns then you are correct, conduit is not necessary. But if it is a return air plenum then someone needs to make sure that the exposed cables are "Plenum" rated. If they are not then it would be necessary to put them into a metal raceway.

There is no ONE answer to this type of question.
 

caj1962

Senior Member
Re: Telephone Lines in Conduit

feel fortunate that it is stapled. What I see alot of times is the lift and fling method for installing phone cables. Lift the tile fling it as far as you can repeat as needed.
 
G

Guest

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Re: Telephone Lines in Conduit

Originally posted by tom baker:
See Article 800. There is little danger of shock or fire from telecom wiring, conduit is not typically required. Also if its ahead of the network interface the wiring belongs to the Telco.
Put your VOM on a ringing line and you might change your mind. When a phone line rings, there's 90 V RMS AC at 20 HZ on the line. It's enough to give you a jolt you won't soon forget. Thus, it's hard to miss!

At rest the phone line is closer to 48-volts.

If your body is the fault path you will feel a phone line, and you will really feel it when it rings.

../Wayne
 

dereckbc

Moderator
Staff member
Location
Plano, TX
Re: Telephone Lines in Conduit

Wayne the impedance is so high on a telephone line it cannot start a fire. You can short the leads out and there is no danger from talk battery or ring voltage.
 
G

Guest

Guest
Re: Telephone Lines in Conduit

Understood. No fire danger. Just shock value.

../Wayne C.
 
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