480and 120v. in same counduit

[powerp]

I need to know if is legal by the electric code. to install high voltage and low voltage in the same conduit or box.thankyou.

 

[charlie b]

Yes, if they both have an insulation system rated for the higher voltage. The requirements are in 300.3(C).

 

[don_resqcapt19]

What is the function of the two sets of conductors? There are cases where the rule Charlie cited does not apply.

 

[iwire]

I need to know if is legal by the electric code. to install high voltage and low voltage in the same conduit or box.thankyou.

For what it is worth you may want to drop the high and low voltage terms.

The IEEE considers both 120 and 480 volts to be low voltage.

Here is a list that gives the basic idea. Consider it more or less correct, there is always some fighting about it.

• Low Voltage = Voltage levels that are less than or equal to 1 kV
• Medium Voltage = Voltage levels that are greater than 1 kV, but less than or equal to 69 kV
• High Voltage = Voltage levels that are greater than 69 kV, but less than or equal to 230 kV
• Extra High Voltage = Voltage levels that are greater than 230 kV, but less than or equal to 800 kV
• Ultra High Voltage = Voltage levels that are greater than 800 kV

 

[tom baker]

Thanks IWire. The NEC does not use the term hi and lo voltage.

And one of the most misquoted sections in the NEC is 300.3(C)(1). Read the FPN and section 90.3
Then read the title of Article 725 "The mother of all low voltage articles".
There are several articles in the NEC that deal with systems that operate below 50 volts.
See if you can find those and note the title does not include the term "Low Voltage". The code authors must of known this when the articles were written. By the way, one goes back to the 1930s.