×
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 Hi-Pot testing

Transformer Hi-Pot testing

Transformer Hi-Pot testing

(OP)
What is the recommended voltage test level on a transformer winding. My old rule of thumb is 2x the working voltage. Is this OK with a DC tester?

RE: Transformer Hi-Pot testing

For testing transformers we do several tests.  

Disconnect all high, low and neutral connections.  Tie all high voltage connections together, all low voltage connections together with neutral.  Megger, and maintain for 1 minute,

1) the high voltage winding to low voltage(with Neutral)and to ground,
2) High voltage winding to ground,
3) Low voltage winding to high voltage winding and to ground,
4) Low voltage winding to ground,
5) and High voltage winding to low voltage winding.

For oil filled transformer:
Transformer Voltage: 0 -600, DC test: 1000V, Min acceptable resistance: 100 Mohms
Transformer Voltage: 601 - 2500, DC test: 2500, Min acceptable resistance: 1000 Mohms
Transformer Voltage: 2501 - 15000, DC test: 5000. Min acceptable resistance: 5000 Mohms

I don't know if these are the recommended test voltages or where the source came from.  Unfortunately, that is not documented in our test procedures.

______________________________________________________________________________
This is normally the space where people post something insightful.

RE: Transformer Hi-Pot testing

I don't have the document handy at the moment.  But I believe NETA should have some recommended practice for hi-pot testing.  

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