Definition of ungrounded conductors and feeder

[hhsting]

Understand had some sort of previous post regarding menu board drive thru sign but it closed without having any NEC 2014 reference as to what ungrounded conductors are and now I am having difficult time applying it to which cables since menuboards have both communication cable in one conduit and power cables second conduit

Question1. Is their a definition of ungrounded conductors in the NEC 2014? Do communication cables have ungrounded cables or just power cables do? It is not clear. The reason is NEC 2014 section 600.6 just says disconnect ungrounded conductors so not sure what it means.


Question2. Also NEC 2014 section 600.6 says feeders. Are communication cables count as feeders?

 

[LarryFine]

Only power wiring; specifically, wires (intentionally) carrying voltage relative to a grounded conductor and/or earth.

 

[tom baker]

Q2.
No

 

[hhsting]

Only power wiring; specifically, wires (intentionally) carrying voltage relative to a grounded conductor and/or earth.

Is their definition in NEC 2014 ungrounded conductors? Having hard time enforcing 600.6. Plans provide disconnect for both communication and power cables

 

[ptonsparky]

Shut the power off to the communications. Via a shunt trip breaker or something similar for fuel pumps.

 

[suemarkp]

The way I read 600.6 it says each system, or feeder circuit, or branch circuit supplying the thing must have a disconnect. I don't see a requirement to disconnect any communications wiring and especially not simultaneously. Depending on the communications signal, there may be other articles requiring it be disconnected. Would probably depend on if it is a network cable, class 1, class 2, or class 3 circuit, or what not.

As far as ungrounded is defined in article 100, all circuits must have some ungrounded conductors. If all were grounded, they would all be shorted out and not function. In something like an ethernet connection, all of the conductors are ungrounded. Control/comm signals many times have a connector which can be pulled. I could see this like a cord-and-plug disconnect if a disconnect is required.

 

[hhsting]

The way I read 600.6 it says each system, or feeder circuit, or branch circuit supplying the thing must have a disconnect. I don't see a requirement to disconnect any communications wiring and especially not simultaneously. Depending on the communications signal, there may be other articles requiring it be disconnected. Would probably depend on if it is a network cable, class 1, class 2, or class 3 circuit, or what not.

As far as ungrounded is defined in article 100, all circuits must have some ungrounded conductors. If all were grounded, they would all be shorted out and not function. In something like an ethernet connection, all of the conductors are ungrounded. Control/comm signals many times have a connector which can be pulled. I could see this like a cord-and-plug disconnect if a disconnect is required.

Just found out that communication cables are cat6 network cables to the menuboard.

Would that require disconnect any other section or NEC 2014 section 600.6(A) at menuboard?

 

[tom baker]

Ethernet cat 6e, or similar is an article 725 class 2 system, or low voltage, same as T stat in your house. No disconnect needed. Before another question is asked, read rules in 725 on class 2 wiring.