×
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

Design of Sudden Pressure Relay Blocking Scheme for Transformer

Design of Sudden Pressure Relay Blocking Scheme for Transformer

Design of Sudden Pressure Relay Blocking Scheme for Transformer

(OP)
How to design SPR blocking scheme using 63 and 50 Fast instantaneous over current element?
Is SPR used for tripping the relay for internal faults only?

How will it block tripping if 63 contacts are short because of transient?

The logic I'm having in my mind is= 63A And not 63B not 87 not  50) will trip the relay , is my thinking correct?

RE: Design of Sudden Pressure Relay Blocking Scheme for Transformer

Sudden pressure relay is used for detection of internal transformer faults.  But they are sometimes prone to mis-operation during transients. Blocking schemes can be used to block operation during through faults.  I've heard of these schemes, but never seen one used.  

If you have an energize-to-trip scheme, you'll need a normally closed contact in series with the 63 tripping contact ("a" contact) that will open during whatever conditions you want to block.

The differential 87 trip contact should not be blocked.   

David Castor
www.cvoes.com

RE: Design of Sudden Pressure Relay Blocking Scheme for Transformer

As was pointed out to me by another engineer, 63 relays can pickup during sysimic events, and should be blocked to prevent misoperation. However your point about transits is valid.

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