×
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

10MV+A Transformer DGA High Hydrogen Level

10MV+A Transformer DGA High Hydrogen Level

10MV+A Transformer DGA High Hydrogen Level

(OP)
Two new oil filled 10MV·A transformers 44kV/4.16kV were installed connected to the same source. After two years DGA indicated very high hydrogen levels in one of the transformers (>20,000ppm). Methane>1900, Ethane>200, Carbon Dioxide>1000. A Radio Interference Voltage test by the transformer manufacturer at 200% of rated voltage showed an increase from 5 microvolts to more than 500 microvolts. The other transformer DGA results were normal. There is no indication or record of unusual events during the two years of operation, loading has been less than 5MV·A per transformer.
What is the likely cause of the problem? What can be done to prevent such an occurrence?

RE: 10MV+A Transformer DGA High Hydrogen Level

See DISSOLVED GAS ANALYSIS OF MINERAL OIL INSULATING FLUIDS Written by: Joseph B. DiGiorgio, Ph.D
http://www.nttworldwide.com/tech2102.htm
Also
IEEE guide for the interpretation of gases generated in oil-immersed transformers
IEEE Std C57.104-1991

Abstract:
Detailed procedures for analyzing gas from gas spaces or gas-collecting devices as well as gas dissolved in oil are described for use in power transformers. The procedures cover: (1) the calibration and use of field instruments for detecting and estimating the amount of combustible gases present in gas blankets above oil, or in gas detector relays; (2) the use of fixed instruments for detecting an determining the quantity of combustible gases present in gas-blanketed equipment; (3) obtaining samples of gas and oil from the transformer for laboratory analysis; (4) laboratory methods for analyzing the gas blanket and the gases extracted from the oil; and (5) interpreting the results in terms of transformer serviceability. The intent is to provide the operator with positive and useful information concerning the serviceability of the equipment. An extensive bibliography on gas evolution, detection, and interpretation is included

RE: 10MV+A Transformer DGA High Hydrogen Level

(OP)
Thanks to both jghrist and jbartos. Both suggestions were helpful.

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