Dissolved Gas Analysis of Oil in Load Tap Changers
General Information

Company Name  _______________________________________________
Name of person providing the information ___________________________
Phone Number ________________________________________________

Where choices are given please check/circle the appropriate selection.

How long have you been performing routine DGA of LTC's? : _______________________ 

Did you remove dissolved gas from the LTC oil prior to starting the sampling program? :

______Yes;  ______ No

Where is the dissolved gas analysis of the oil performed? : 

Company Laboratory _________________: Outside Laboratory_____________________

LTC oil sampling frequency :   
Example as follows:
Tap Changer Type:  All types except the following  sampled       1      time(s) per    2   year(s)
Tap Changer Type:         Westinghouse  UTT           sampled       2      time(s) per    1   year(s)

Your Company's Sampling frequency:
Tap Changer Type: __________________________sampled _______ time(s) per ____year(s)
Tap Changer Type: __________________________sampled _______ time(s) per ____year(s)
Tap Changer Type: __________________________sampled _______ time(s) per ____year(s)
Tap Changer Type: __________________________sampled _______ time(s) per ____year(s)

Do you use DGA of the LTC oil as the ONLY method to diagnose LTC problems:

______Yes;  ______ No

If the answer is NO; What other tools do you use to diagnose problems with LTC's?

________ Infrared Camera
________ Temperature Measurements
________ Dielectric Breakdown of the Oil
________ Water Content of the Oil
________ Other ____________________________________
  
Dissolved Gas Analysis of Oil in Load Tap Changers

Transformer and LTC Information


Transformer nameplate information:
(Provide a copy of the nameplate drawing if more convenient)
Manufacturer ______________		Serial Number ________________
____ Autotransformer;	____Two Winding;		___Three Winding
Rating __________/__________/__________MVA  KVA (circle one)
Voltage Rating __________/__________/__________ KV

Load Tap Changer Information:
Manufacturer ____________		Model ____________
Type:  _____Resistive; _____ Preventative Auto-transformer
Transfer or Diverter Switch type: Vacuum _____; Break in Oil _____
Current rating ____________ Regulation  "__________%
Series transformer present?: Yes _____; No _____
Volts per tap: ____________
Tank type: ____Free Breather; _____Desiccant Breather; _____Sealed 
Oil filtration equipment present?: Yes _____; No _____
Operations per month _________
Have there been special modifications made to the LTC.
_________________________________________________________
_________________________________________________________
_________________________________________________________




Dissolved Gas Analysis of Oil in Load Tap Changers

Dissolved Gas Analysis & LTC Maintenance History

Transformer Serial Number ______________________________________________
LTC Manufacturer___________________	Model ____________________________

In the following chart indicate your DGA history for this load tap changer
Make sure to indicate in the comment column the LTC, overhauls, contact replacements, oil replacement, oil degassing activities to allow proper analysis. 



Date

LTC
Counter
Reading

Dissolved Gas Levels in ppm





Comments





Hydrogen H2

Acetylene
C2H2

Ethylene C2H4

Ethane
C2H6















































































































































							Page _________  of  _________


Dissolved Gas Analysis of Oil in Load Tap Changers

Dissolved Gas Analysis History

Transformer Serial Number ___________________________________________

Does this tap changer operate through neutral? 	

Yes ________ No ________


Has Dissolved Gas Analysis indicated a problem with this tap changer?

Yes ________ No ________


If yes, please describe the situation and provide any substantiating information.

______________________________________________________________________________
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