×
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

Surge Arrester Rating for Delta Tertiary

Surge Arrester Rating for Delta Tertiary

Surge Arrester Rating for Delta Tertiary

(OP)
I'm working on the specification for a 161/69/13.2 kV, 36/48/60 MVA, autotransformer with a loaded delta tertiary and a zig-zag grounding transformer downstream of the tertiary. The HV and LV windings are wye connected and solidly grounded. I'm specifying the tertiary winding with a 110 kV BIL and an arrester rating of 10 kV duty cycle or 8.4 kV MCOV. I've seen some utilities use an arrester rated 15 kV or 18 kV duty cycle on a similar unit. Has anyone worked on a similar design? Thanks for your help.

RE: Surge Arrester Rating for Delta Tertiary

If you didn't have the grounding transformer, you'd use the 15 kV or 18 kV duty cycle rating.

With the grounding transformer, a 10 kV rating can be used.

RE: Surge Arrester Rating for Delta Tertiary

10kV is enough if grounding transformer is sized for effectivelly grounded 13.2 kV system

RE: Surge Arrester Rating for Delta Tertiary

Could the tertiary be energized without the grounding transformer connected? If so, use the higher rating.

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