×
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

MBCi and unit protection

MBCi and unit protection

MBCi and unit protection

(OP)
Hello,

I have an 11kV substation that utilises Unit and O/C protection and has 6 ring feeders.

The unit protection used a mixture of Tranlsay H and SDP relays.

the relays are being replaced throughout with MBCis.  If there is a pilot fault, will the MBCis initiate a trip at both end of the cable?

Thanks guys  

RE: MBCi and unit protection

(OP)
The second question is, in order to convert a balanced volatge unit protection scheme to a circulating current scheme, it is just a case of changing the relays and uncrossing the pilots?

RE: MBCi and unit protection

The MBCI circulating current will operate for a open circuit pilot, but not operate for a shorted pilot. It will operate at both ends.

The Translay H Balanced voltage relay will not operate for an open circuit pilot, but should operate for a short circuit pilot.

The pilots are crossed when changing from a Balanced voltage to circulating current.

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