×
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

Directional Overcurrent and Earth Fault Protection

Directional Overcurrent and Earth Fault Protection

Directional Overcurrent and Earth Fault Protection

(OP)
Hi



I have a one or two questions that I would like some clarity on regarding protection using directional overcurrent and earth fault protection.

1. When using a 90°-30° characteristic (30° RCA) why is it recommended that the relay is used for the protection of plain feeders with the zero sequence source behind the relaying point.

2. When using a 90°-45° why is it that the connection is recommended for the protection of transformer feeders or feeders that have a zero sequence source in front of the relay

3. When would one set the MTA or RCA different for phase faults as opposed to earth faults.
30°
4. If I use an older style 30° or 60°connection as opposed to a quadrature type connection is it true in saying the MTA would be at 30° and MTA is at 60° obviously in both cases the MTA is at the current for the faulted phase under consideration w.r.t its reference .

Much appreciated



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