×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

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!
  • Students Click Here

*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.

Students Click Here

Jobs

skm modeling of 250' bus duct

skm modeling of 250' bus duct

skm modeling of 250' bus duct

(OP)
Greetings!
I am performing a short circuit and arc flash for a multi-story building with 4000A 480V busduct risers. Each floor has several plug-in breakers. Do I model this busduct as one long bus or each "floor" is it's own bus? I just need to err on the conservative side for a preliminary analysis at this point. Any ideas?
Thanks,
   

RE: skm modeling of 250' bus duct

The points where the busplugs are connected should be modeled as buses in the software; the busduct itself should be modeled as impedances between the buses.

Don't be confused by the word 'bus' as it is used in the software; it means a connection point. The busduct is an impedance just like a cable. As a matter of fact, SKM lists busducts in its cable library.

RE: skm modeling of 250' bus duct

(OP)
Perfect clear answer. It seems so obvious now! Thank you very much.

RE: skm modeling of 250' bus duct

The T&D book is an excellent resource for BUS impedance values.  Pg 396 according to my log book ;)

It would be interesting to compare what is the impedance obtained from SKM vs T&D.

RE: skm modeling of 250' bus duct

Bus duct manufacturers publish tables of impedance values as well.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

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!


Resources