Power vs. Control Wiring

[Telaid]

I have to run some power and control wire and im confused as to what needs to be run in separate conduit. What is considered Control wiring? Where can I find a description in the NEC or the requirements?

One if the runs is from a control panel to a visual display unit. The unit is powered by 24VDC and has a control cable that connects it to the PLC in the control panel. Does the 24VDC and the control wire need to be run in separate conduit?

Any help is appreciated.

Thanks
Ron

 

[petersonra]

I have to run some power and control wire and im confused as to what needs to be run in separate conduit. What is considered Control wiring? Where can I find a description in the NEC or the requirements?

Control circuits are often class 1,2, or 3 circuits, but do not have to be. See article 725.

One if the runs is from a control panel to a visual display unit. The unit is powered by 24VDC and has a control cable that connects it to the PLC in the control panel. Does the 24VDC and the control wire need to be run in separate conduit?
Ron

The answer is that you probably have to run them seperately. Often you are not required to run cables covered by article 725 in conduit at all. The 24VDC circuit is probably covered in article 725. The other cable might well be covered in chapter 8.

 

[goskime]

It sounds like the control wiring may be 24vdc if that is the power supply to the unit. So you might get a different answer than if you have 24 vdc going to the unit and 120v control power in which case they would have to be separated. Any factory books on this, to show you how the manufacturer expected the wiring to be run? Good Luck.

 

[lquadros]

24volt circuit.

24volt circuit.

I presume that this 24VDC originates from the same source. I think, in this case you may be able to even use one single multiconductor cable. For the mechanical protection of this cable, you may need a flexible conduit, EMT or Rigid depending on the length of run and environment it will be used in.