Dissolved Gas Analysis Of Load Tap Changers

 Working Group

Project scope: 

This guide discusses and recommends methods of testing and evaluating dissolved gases in mineral based transformer oils found in Load Tap Changers (LTCs).  General types of LTC mechanisms, breathing configuration and electrical design will be included as evaluation criteria in determining when mechanical damage or failure can occur. Dissolved Gas Analysis (DGA) provides a non-invasive means of signaling when maintenance of the LTC is required.  This guide will provide the information needed to develop a baseline health curve for any type of equipment covered within and will provide basic gassing levels.  Ultimately, the user must set their own standards based on local conditions.

Insulating Fluids Subcommittee Chair:

Dave Wallach

Duke Energy

Charlotte, NC


Phone: (980) 373-4167


C57.139 Working Group Chair:

Dave Wallach

Duke Energy

Charlotte, NC


Phone: (980) 373-4167


C57.139 Working Group Vice-Chair:

Mark Cheatham

General Electric

Gastonia, NC


Phone: (704) 675-2187


C57.139 Working Group  Secretary:

Susan McNelly

Xcel Energy

250 Marquette Avenue, Suite 800

Minneapolis, MN  55401


Phone: (612) 330-6904

Fax: (612) 573-9190



Fall 2014 Unapproved Minutes   posted 22Oct2014

Fall 2014 Agenda  Posted 30Sep2013

C57.139, Draft 5  Posted 11Sep2014, committee password required

C57.139 D4 Comments  Posted 11Sep2014,

Previous Meeting Info:

Spring 2014 Meeting Minutes   posted 12May2014

Fall 2013 Meeting Minutes  Posted 08Nov2013

Spring 2013 Unapproved Minutes   posted 23Mar2013

Spring 2013 Presentation LTC Nomograms - Jakob/Dukarm Posted 19Mar2013

Spring 2013 Presentation - Dukarm Posted 06Mar2013

Appendix D -Draft 2  Posted 03Mar2013, committee password required

Fall 2012 Unapproved Minutes   posted 24Oct2012

Fall 2012 Pruente Presentation  Posted 23Oct2012

Spring 2012 - Dukarm/Jakob Presentation  Posted 13Mar2012

Spring 2012 - Duval PresentationPosted 08Mar2012


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Last update: 22-Oct-2014

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