Mulitple Voltages in Same Conduit

[Nsmith]

Are you allowed to run 208VAC and 480VAC in the same conduit?

 

[iwire]

Yes, as long as the insulation rating of all the conductors exceeds the highest voltage in the conduit.

 

[raider1]

I agree with Bob, take a look at 300.3(C)(1).

Chris

 

[Nsmith]

Thanks, Does any special designation need to be made on the conduit or the breakers feed the conduit? is there an article in the code you know of that refers to this?

 

[raider1]

There is no special marking requirement for the raceway or j-boxes.

The conductors will have to be identified in accordance with 210.5.

Chris

 

[mull982]

As others have said, most LV cable insulation will be rated for 600V and can therefore be used in the same conduit.

Does anyone know why 600V is used as the benchmark for insulation on most LV cables?

 

[Dennis Alwon]

Does anyone know why 600V is used as the benchmark for insulation on most LV cables?

Although there is no official definition of Low Voltage, the NEC appears to look at voltages over 600V and those 600V and less. Perhaps this is why the manufacturers choose 600V as their guide. It would be advantageous to make all wires under 600V marked 600V just for ease of installation as the op is asking about. A 12V wire marked 600V makes the install a bit easier.

 

[augie47]

You might want to be sure you keep 210.5(C) & 200.6(D) in mind,