×
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

Transformer core bushing

Transformer core bushing

Transformer core bushing

(OP)
Hi everyone,

While working with a 36/25kV 25MVA power transformer, I came across something labelled as a 'core bushing terminal'. Is this a grounding connector for the transformer core? I've never came across this before.

Can someone please clarify its purpose?

Thanks

RE: Transformer core bushing

It is likely to be a bushing which normally has an earth link fitted to connect the bushing to the tank. Its purpose is to allow testing of the insulation between the core and the tank.

RE: Transformer core bushing

On larger transformer I usually specify the core ground to be brought out of the transformer tank through the bushing and bonded to the tank on the outside. It allows me to remove the ground bond and check for additional inadvertent grounds.

"Throughout space there is energy. Is this energy static or kinetic! If static our hopes are in vain; if kinetic — and this we know it is, for certain — then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature". – Nikola Tesla

RE: Transformer core bushing

Normally there will be three small bushings ( 2 or 6 kV) in a terminal box over the tank- one connected to core,second to core clamping structure and the third to tank .In service all will be shorted together. But after removing links one can check IR between core to earth,coreclamp to earth and core to coreclamp. Usually a minimum IR of 1 Megohm is expected in service. Any shorting can be an abnormality that may lead to circulating currents and overheating.

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