×
Follow Us
Page 2 of 2 FirstFirst 12
Results 11 to 14 of 14

Transformer power factor under vacuum

 Jump to latest post
Page 2 of 2 FirstFirst 12
    #11
  1. NBatson's Avatar
    NBatson is offline
    I NETA BREAK
    Junior Member
    Join Date
    Feb 2019
    Location
    TX Gulf Coast
    Posts
    19
    Reputation

    yep

    Quote Originally Posted by SecondGen View Post
    Power factor testing an empty liquid-filled transformer?

    Attachment 383


    Doble Power Factor Test. Obviously not the recommended way but it can be done under reduced voltages.

    Delta windings

    161kv+ -10kv
    115-138 -5kv
    34-69 -2kv
    12-25 -1kv
    -12 .5kv

    wye windings

    12kv+ -1kv
    below12kv -.5kv

  2. #12
  3. SecondGen's Avatar
    SecondGen is offline
    I push buttons.
    NETA Level III Pro Subscriber
    Join Date
    Jan 2014
    Location
    United States
    Posts
    508
    Reputation
    Quote Originally Posted by NBatson View Post
    Doble Power Factor Test. Obviously not the recommended way but it can be done under reduced voltages.
    This is interesting, I don't think we've ever done it at my shop. What is the main purpose of testing without oil?

  4. #13
  5. NBatson's Avatar
    NBatson is offline
    I NETA BREAK
    Junior Member
    Join Date
    Feb 2019
    Location
    TX Gulf Coast
    Posts
    19
    Reputation
    Quote Originally Posted by SecondGen View Post
    This is interesting, I don't think we've ever done it at my shop. What is the main purpose of testing without oil?
    There are different scenarios but an example would be:

    If you pull the core and coils you could test those separately to see if the root cause was in the core and windings or if its insulation parts in the tank.

    Another example could be if your testing the 480v secondary side and your suspecting faulty bushing its hard to guard off that little bushing. You could drain and test it strait to the coil to place the blame on the bushing or to rule it out.

    We had the opportunity to take the doble training class and it was super full of information. I'm still new to the testing field so I really enjoy stuff like that.

  6. #14
  7. SecondGen's Avatar
    SecondGen is offline
    I push buttons.
    NETA Level III Pro Subscriber
    Join Date
    Jan 2014
    Location
    United States
    Posts
    508
    Reputation
    Quote Originally Posted by NBatson View Post
    There are different scenarios but an example would be:

    If you pull the core and coils you could test those separately to see if the root cause was in the core and windings or if its insulation parts in the tank.

    Another example could be if your testing the 480v secondary side and your suspecting faulty bushing its hard to guard off that little bushing. You could drain and test it strait to the coil to place the blame on the bushing or to rule it out.

    We had the opportunity to take the doble training class and it was super full of information. I'm still new to the testing field so I really enjoy stuff like that.
    That makes sense, I figured it was most likely used in diagnostics or specialized applications. Have you ever done it that way in the field? Just curious about what kind of numbers you get.

Page 2 of 2 FirstFirst 12
Subscribe

Share this thread

Related Topics

  1. Transformer Oil Pressure when Power Factor Testing
    By ElectricalTestTech in forum Electrical Testing Talk
    Replies: 8
    Last Post: October 3, 2020, 09:41 AM
  2. Power Factor for New Mineral Oil
    By Salcama in forum NETA Level 3 Exam
    Replies: 4
    Last Post: February 22, 2020, 05:12 PM
  3. Power factor testing mode of operation
    By E-DivMafia in forum NETA Level 2 Exam
    Replies: 1
    Last Post: October 31, 2018, 02:22 PM
  4. Replies: 9
    Last Post: August 16, 2018, 02:28 PM
  5. Tan / Delta or Power Factor Testing of Dry Type Transformer
    By mask12900 in forum Electrical Testing Talk
    Replies: 1
    Last Post: January 1, 2018, 08:41 PM

Tags for this Thread

Follow us


Explore TestGuy


NETA Certification Training


NICET Electrical Power Testing


Help and Support




You are viewing the archives. Enjoy new features and join the conversation at wiki.testguy.net