AC & DC Cable in Same Cable Tray

[msimms]

I've had this issue arise on a job site that I would like to clear up. We're routing 1-3/C#250MCM from an existing DC source, to a new building, and 1-3/C350MCM for UPS cable to that same building. Since this is old jobsite, getting from the existing plant to the building is diffucult to find proper mounting locations for cable tray and thus far, with the tight area to route, I'm planning on sitting a new 12" tray to get both cables to the building. However, a field electrical engineer approached me, stating I couldn't run both DC and AC cables together. I can not find any code requirements that state this, nor can I see a plausible reason that using the same tray would cause noise issues between AC and DC cables. If anyone could clarify and point me to any section in the code, or provide insight from work experience, I would greatly appreciate it.

 

[raider1]

Take a look at 300.3(C)(1).

Chris

 

[dereckbc]

As long as we are talking about building power and lighting you can mix DC and AC. It is only when you get into CL1, CL2, CL3 and various cable insulation ratings do you get into trouble between AC anc DC power cables.

I do this all the time in Telephone offices. Normally we like to seperate the two for technical reason, but as long as the insulation types are like, (RHH/RHW or THhN 600 volt), or power limited, I don't know of any code reason why they cannot be mixed in a cable tray.

 

[djohns6]

We do it all the time in Substations .

 

[Hendrix]

We do it all the time in Substations .

Up here, the utility guys do alot of things that we can't do.

 

[dereckbc]

Up here, the utility guys do alot of things that we can't do.

Yes but 300.3(c)(1) tells you that you can run AC/DC conductors, providing the insulation rating are equal to the max voltage applied.

 

[msimms]

thanks a lot to everyone; i was comfortable doing it; just wanted verification.

 

[raider1]

Your welcome.

Chris

 

[drbond24]

I always thought AC/DC went quite well together.