Smart questions
Smart answers
Smart people
Join Eng-Tips Forums
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.

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.

dltee (Electrical) (OP)
30 Aug 05 11:01
Will someone be able to show me how to calculate voltage drop on the medium voltage cable (i.e 11 miles of 350 Kcmil 15 KV EPR cable with 133% insulation to support 150A Load at 13,200 volt)?  There are plenty of calculations available for low voltage system.
rbulsara (Electrical)
30 Aug 05 12:52
Basic method is no different. It is still I/Z. Cable manufacture should be able to provide you with the reactance and resistance values of the cable and use those values. VD=I(R+jX). Use per phase values. I is the line current, VD will be L-N, regardless of the system configuration.

If you have a software, use that.
rbulsara (Electrical)
30 Aug 05 12:54
See this. I hate to do this normally (to pick a site and post it here, but this was just easy..)

http://www.okonite.com/engineering/voltage-regulation.html
dpc (Electrical)
30 Aug 05 14:32
For 11 miles of 15 kV cable, you may want to also consider the capacitive reactance of the cable and resulting charging current.  This is generally neglected in low voltage calculations, but could be of interest in 11 miles of cable.  For 150A of load (what pf?), the charging current may not be too critical, but becomes more important as the cable gets longer and longer.  

You would need a cable model that includes appropriate shunt capacitance in addition to the series inductance and resistance.


 
cuky2000 (Electrical)
30 Aug 05 16:06
See the enclose sample

http://cuky2000.250free.com/VD.pdf

ArtAllm (Electrical)
7 Sep 05 5:01
To get precise values of voltage drop you have also to take into consideration the ground temperature, which has an influence on the cable resistance.

www.allmend.net

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