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 Forums!
  • 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.

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.

Can you add on to existing underground duct banks?

Can you add on to existing underground duct banks?

(OP)
We have a project where we will be relocating a number of 150 Hp, 480V pump motors about 50'.  The existing feeders are installed in an underground duct bank. The feeders are approximately 300' in length.

To re-feed the motors overhead will be very expensive. Adding a pullbox at the existing location or installing a manhole are also not options.

The entire area between the new and old location will be excavated prior to building a foundation for the new equipment, thus exposing the existing duct bank.

It seems a shame not to re-use the existing, but I have never heard of extending underground duct bank ..Can this be done?  Any issues?  

RE: Can you add on to existing underground duct banks?

Don't know of a reason not to extend the duct. You would have to chip the concrete back enough to get to the duct. Problem is not to damage the existing cable.

RE: Can you add on to existing underground duct banks?

How about just building a new duct bank right beside the old one?

MAKE SURE that you document/update all of your exisitng records.

RE: Can you add on to existing underground duct banks?

You cannot splice conductors in a conduit, so I assume you would pull out the existing conductors, intercept and extend the duct bank to the new location and re-pull all new conductors.

If this is your intent, it is possible.  You would need to specify the chipping back of the concrete enough to expose the conduit beyond where, ( it is assumed), the elbows currently bring it up vertically through the floor to the existing motors, and then extend the horizontal conduit runs to your new equipment locations.

I don't know your configuration, but I have also left the risers in place, installed an empty switchgear section to use as a pullbox above grade and extended them either back down underground, or overhead.  Not the most elegant solution, but effective and one of the least costly options as you would utilize most of the existing duct bank.

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!


Related News

Resources

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