×
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

short circuit capacity

short circuit capacity

short circuit capacity

(OP)
please somebody tell me how can I know that a specified maximum current capacity that runs through the metallic shield of a power cable is enough.
I mean when for example the conductor short circuit capacity of a cable is 25 KA then what should be the limit
for the shield.assume that the cable is single core and
it may be directly burried in the ground or may be laid
on trays.I have specified the 25KA and one manufacturer
has specified about 700 A for the shield .another one has specified 2.3KA and so on. the cable is going to be solid
bonded at both ends.

another problem is that in measurement centers sometimes
we use output contacts to send pulses to a remote center.
some manufacturers use 2 output contacts and some offer
4 output contacts to send information about both imported
and exported energy and in both active and reactive states.
I want to know if we use  2 output pulses what would be
lost? what is the disadvantage?is it too critical to have
the second type?lets assume that we can measure all for states in the first type of device.
thanks

RE: short circuit capacity

The short circuit rating of cable shield is generalyy given in Amps for a given number of seconds.  So you need to look at the amount of ground fault current available on your system, and how fast a ground fault will be cleared and specify that the cable manufacturers meet this requirement.

Okonite had a good description of this on their site:

http://www.okonite.com/engineering/shielding-currents.html

Gord

RE: short circuit capacity

(OP)
Thank you gordonl ,that was very helpful.
can you help me on second question too?

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! Already a Member? Login


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