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!

*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.

Jobs

Hermetically sealed voltage & current transformers - CT VT

Hermetically sealed voltage & current transformers - CT VT

(OP)
Good day,

In our network we have several Hermetically sealed voltage and current transformers ranging from 33 - 220kV.

There are several which have developed oil leaks.

Can these be repaired as they are Hermetically sealed units?

We would preferably repair them in-house / on site as we are a remote Sub Africa utility.

Thank you

RE: Hermetically sealed voltage & current transformers - CT VT

Sure, you can or rather should repair. A leaking CT/VT is dangerous to keep in system. Hermetic sealing can be of different types- just sealing with nitrogen or dry air over oil at a slight positive pressure, a metallic or rubber bellow over the oil. While repairing and fixing oil level, please remember these simple rules of science -air will dissolve in to oil by 8 % by volume, oil volume will expand by approx. 0.8 % for every 10C rise in temperature.

RE: Hermetically sealed voltage & current transformers - CT VT

It depends a lot on the type of design. Care has to be taken not to trap air in the unit.

If it uses a metallic bellows expansion system, I would recommend discussing it with the manufacturer.

Often times it's not as easy as it looks to repair a leaking instrument transformer.

RE: Hermetically sealed voltage & current transformers - CT VT

(OP)
Thank you for the good insight. I think we will first try and strip down a out of service faulty unit and see how it goes. I will try post feedback here on the progress and findings. I will definitely contact the manufacturer.
Thanks

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


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close