# NEC Article about mixed voltages in conduit



## Gatorowl (Jul 8, 2017)

What article states that it is not permissible to mix voltages in the same conduit?


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## HackWork (Oct 2, 2009)

Gatorowl said:


> What article states that it is not permissible to mix voltages in the same conduit?


It's a little more complicated than that. You can mix various voltages and in many cases even high and low voltage if the conductor insulation can handle the highest voltage. 

What is the exact situation you are asking about?


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## frenchelectrican (Mar 15, 2007)

Gatorowl said:


> What article states that it is not permissible to mix voltages in the same conduit?


It will show up in couple spots in NEC but normally most conductors they have voltage rating so it kinda common to have low and high voltages in the conduit.

but there are some area or items it is very specfic on it.

There is couple arts they have power limited cable or conductors in there. so that question will varies. 

any specfic reason for that situation you are looking for ?


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## wildleg (Apr 12, 2009)

search for class 2 circuits. that might be what you are looking for. 720-760, chapter 8, etc.


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## conclavicus (Jul 25, 2016)

wildleg said:


> search for class 2 circuits. that might be what you are looking for. 720-760, chapter 8, etc.


 Are cable trays more liberal when it comes to this question???? Any NEC directives???


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## Gatorowl (Jul 8, 2017)

HackWork said:


> It's a little more complicated than that. You can mix various voltages and in many cases even high and low voltage if the conductor insulation can handle the highest voltage.
> 
> What is the exact situation you are asking about?


Need to convert an existing 120 volt motor with existing 120volt control conductors to 480 volt for the motor, and still use the existing 120 volt control conductors. All conductors rated for 600 volts. I was thinking that would be a code violation, but maybe not, could not find it in the code book.


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## Big John (May 23, 2010)

The control circuit is often considered a "Class 1" covered in article 725. The workaround is that it's "functionally associated" per 725.48(B)(1) so you can run it with your branch circuit.


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## Gatorowl (Jul 8, 2017)

Big John said:


> The control circuit is often considered a "Class 1" covered in article 725. The workaround is that it's "functionally associated" per 725.48(B)(1) so you can run it with your branch circuit.


Thanks!


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## conclavicus (Jul 25, 2016)

Do cabletrays give even more latitude??


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## chicken steve (Mar 22, 2011)

Actually the cable itself does>>>

http://www.afcweb.com/mc-metal-clad-cables/mc-luminary-type-mc-pcs/mc-luminary/

~CS~


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## MechanicalDVR (Dec 29, 2007)

Gatorowl said:


> Need to convert an existing 120 volt motor with existing 120volt control conductors to 480 volt for the motor, and still use the existing 120 volt control conductors. All conductors rated for 600 volts. I was thinking that would be a code violation, but maybe not, could not find it in the code book.


 @Gatorowl

First of all, welcome aboard!

Secondly that type of conversion is fairly common in some areas of industrial work for a few reasons and done often.


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## wildleg (Apr 12, 2009)

conclavicus said:


> Do cabletrays give even more latitude??


no.

most sections of the code that reference cable trays (medium/low voltage, class 2 ckts, etc) require a barrier to separate the conductors, just like the other sections. 725.133 (2011) is similar as well. so I'd say that cable trays give no more latitude than other methods.


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