Smart questions
Smart answers
Smart people
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Member Login




Remember Me
Forgot Password?
Join Us!

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips now!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

Join Eng-Tips
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Donate Today!

Do you enjoy these
technical forums?
Donate Today! Click Here

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.
Jobs from Indeed

Link To This Forum!

Partner Button
Add Stickiness To Your Site By Linking To This Professionally Managed Technical Forum.
Just copy and paste the
code below into your site.

Samamelectric (Electrical) (OP)
20 Aug 09 9:52
Can I run  a 12,470 volt conduit in the same duct bank as my 480 conduits? If not how much separation would I need?? I have look in the NEC but can't seem to find anything on this. Any input would be appreciated.

 
controlnovice (Electrical)
20 Aug 09 17:10
See section 300.3(C)(2): Not allowed except permitted in a) through (e).

I have 2005 NEC with me.

______________________________________________________________________________
This is normally the space where people post something insightful.

dpc (Electrical)
20 Aug 09 17:29
That NEC article refers to running different voltage systems within the same conduit or cable.  It does not apply to running different voltage system in different conduits within the same duct bank.  This is allowed.  It is permissible to run a 12 kV circuit in one conduit, a 480 V circuit in another conduit and a 24 V dc circuit in a third conduit within a common duct bank.  The problem come when you enter a manhole or handhole, since the high voltage must be isolated from the lower voltages.  

We generally split out separate manholes/handholes for the 15 kV (or any medium-voltage) cables.  Then if you use 600 V insulation for all low-voltage cables, they can occupy the same space in a manhole/handhole.  The other option is to provide a barrier of some type within the manhole to isolate the 12 kV from the lower voltages.

It's good practice to keep the 12 kV ducts segregated in one portion of the duct bank.  We sometimes put two duct banks in a common trench to increase separation, but this is not required by the NEC, AFAIK.   
rbulsara (Electrical)
20 Aug 09 21:56
Agree with dpc.

Rafiq Bulsara
http://www.srengineersct.com

controlnovice (Electrical)
21 Aug 09 8:54
Yes...I need to read the OP better...

 

______________________________________________________________________________
This is normally the space where people post something insightful.

Samamelectric (Electrical) (OP)
21 Aug 09 10:45
Thanks. Thats what I thought. I looked in the code book and could not find anything. Thanks again for all the reply's.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close