1. Power industry transformer demise
Why does insurance complicate investigation?
Lim Sze Hue BEng (Electrical)
Forensic Services Asia Pte Ltd

3. Steel
Copper
Wood

4. Steel
Copper
Wood

8. Bushing
Steel
Tap changer
Copper
Wood

9. Locations of oil in a transformer
Tap Changers

10. UK Statistics
50% of the UK national grid transformer population has aged 40 years or more.
Data is from 2010

11. UK Statistics
Average life 21.3 years

12. Transformer Age at the Time of Failure
FSA Statistics
Transformer Age at the Time of Failure
No. of investigations
Life (years)

13. 50% of the UK national grid transformer population has aged 40 years or more.
Data is from 2010

17. Bushing
Tap changer

18. Effect of Water

19. 15/20 MVA 230/6.9kV

27. Effect of Temperature

28. 11kV to 170V, 37 to 50kA Electric arc furnace transformer
Failed in only 10 years

30. Molecule repeats 1000 -1100 times
Over time, paper molecule fragments

33. Furan Testing
When celluose (paper insulation) molecule de-polymerises, chemicals known as furan compounds or furan is formed. The five furans and their most common causes are listed below.
Rare, lightning

34. A B C D E (A) Normal aging rate (D) High risk of failure
(B) Accelerated aging rate (E) End of expected life of paper
(C) Extensive aging, danger zone insulation and of the transformer

35. Oil purification in July 2014; Failed Sept 2014.
33.6/33.6/15 MVA in ONAN
56/56/25 MVA in ONAF
132/15/11 kV
Step down transformer at an steel electric arc furnace facility
Operated since 1984;
Oil change in 1992;
Oil purification in July 2014;
Failed Sept 2014.

39. Bushing
Tap changer

40. Conductor, usually aluminium
Bushing oil
Ceramic sheds
Transformer tank wall
Oil impregnated alternating paper/aluminium
Transformer oil

42. Video of exploding transformer

45. 168 MVA, 10.5/275 kV 8

53. Direct Clientele Independant power producers
Power utility service provider
Electrical equipment manufacturer
Oil & gas plants
Chemical plant
Medical equipment
Building tenant
Global Food Manufacturer

54. Power Utility Service Provider

55. Comparison between Direct Appointment and Insurance Claims: Time taken to provide requested information

56. No. of investigations

57. No. of investigations
For three investigations, we never received the condition monitoring records

58. 6.876MVA

62. Final Statement