Table 8.13.B. U.S. Transformer Sustained Automatic Outage Counts and Hours by Cause Code and by NERC Region, 2012
 

  Transformer Outage Counts
Sustained Outage Causes FRCC MRO NPCC RFC SERC SPP TRE WECC Contiguous U.S.
Weather, excluding lightning -- -- -- -- 1.00 -- -- -- 1.00
Lightning -- -- -- -- -- -- -- -- --
Environmental -- -- -- -- -- -- -- -- --
Contamination 1.00 -- -- -- -- -- -- -- 1.00
Foreign Interference -- -- -- -- -- -- -- -- --
Fire -- -- -- -- -- -- -- -- --
Vandalism, Terrorism, or Malicious Acts -- -- -- -- -- -- -- -- --
Failed AC Substation Equipment 3.00 1.00 -- 1.00 5.00 -- -- 4.00 14.00
Failed AC/DC Terminal Equipment -- -- -- -- -- -- -- -- --
Failed Protection System Equipment -- 1.00 -- -- 3.00 -- -- -- 4.00
Failed AC Circuit Equipment -- -- -- -- -- -- -- -- --
Failed DC Circuit Equipment -- -- -- -- -- -- -- -- --
Vegetation -- -- -- -- -- -- -- -- --
Power System Condition -- -- -- -- -- -- -- 1.00 1.00
Human Error -- -- -- -- -- -- -- 2.00 2.00
Unknown -- -- -- -- -- -- -- 6.00 6.00
Other -- -- -- -- -- -- -- 3.00 3.00
TOTAL 4.00 2.00 -- 1.00 9.00 -- -- 16.00 32.00

 

  Percentage of Total Transformer Outage Counts
Sustained Outage Causes FRCC MRO NPCC RFC SERC SPP TRE WECC Contiguous U.S.
Weather, excluding lightning 0.00% 0.00% -- 0.00% 11.11% -- -- 0.00% 3.13%
Lightning 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Environmental 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Contamination 25.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 3.13%
Foreign Interference 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Fire 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Vandalism, Terrorism, or Malicious Acts 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Failed AC Substation Equipment 75.00% 50.00% -- 100.00% 55.56% -- -- 25.00% 43.75%
Failed AC/DC Terminal Equipment 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Failed Protection System Equipment 0.00% 50.00% -- 0.00% 33.33% -- -- 0.00% 12.50%
Failed AC Circuit Equipment 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Failed DC Circuit Equipment 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Vegetation 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Power System Condition 0.00% 0.00% -- 0.00% 0.00% -- -- 6.25% 3.13%
Human Error 0.00% 0.00% -- 0.00% 0.00% -- -- 12.50% 6.25%
Unknown 0.00% 0.00% -- 0.00% 0.00% -- -- 37.50% 18.75%
Other 0.00% 0.00% -- 0.00% 0.00% -- -- 18.75% 9.38%
TOTAL 100.00% 100.00% -- 100.00% 100.00% -- -- 100.00% 100.00%

 

  Transformer Outage Hours
Sustained Outage Causes FRCC MRO NPCC RFC SERC SPP TRE WECC Contiguous U.S.
Weather, excluding lightning -- -- -- -- 2.07 -- -- -- 2.07
Lightning -- -- -- -- -- -- -- -- --
Environmental -- -- -- -- -- -- -- -- --
Contamination 22.10 -- -- -- -- -- -- -- 22.10
Foreign Interference -- -- -- -- -- -- -- -- --
Fire -- -- -- -- -- -- -- -- --
Vandalism, Terrorism, or Malicious Acts -- -- -- -- -- -- -- -- --
Failed AC Substation Equipment 2,682.68 132.48 -- 47.83 104.45 -- -- 44.45 3,011.89
Failed AC/DC Terminal Equipment -- -- -- -- -- -- -- -- --
Failed Protection System Equipment -- 20.77 -- -- 211.75 -- -- -- 232.52
Failed AC Circuit Equipment -- -- -- -- -- -- -- -- --
Failed DC Circuit Equipment -- -- -- -- -- -- -- -- --
Vegetation -- -- -- -- -- -- -- -- --
Power System Condition -- -- -- -- -- -- -- 1.32 1.32
Human Error -- -- -- -- -- -- -- 0.40 0.40
Unknown -- -- -- -- -- -- -- 255.37 255.37
Other -- -- -- -- -- -- -- 0.28 0.28
TOTAL 2,704.78 153.25 -- 47.83 318.27 -- -- 301.82 3,525.95

 

  Percentage of Total Transformer Outage Hours
OUTAGE_CAUSE FRCC MRO NPCC RFC SERC SPP TRE WECC Contiguous U.S.
Weather, excluding lightning 0.00% 0.00% -- 0.00% 0.65% -- -- 0.00% 0.06%
Lightning 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Environmental 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Contamination 0.82% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.63%
Foreign Interference 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Fire 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Vandalism, Terrorism, or Malicious Acts 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Failed AC Substation Equipment 99.18% 86.45% -- 100.00% 32.82% -- -- 14.73% 85.42%
Failed AC/DC Terminal Equipment 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Failed Protection System Equipment 0.00% 13.55% -- 0.00% 66.53% -- -- 0.00% 6.59%
Failed AC Circuit Equipment 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Failed DC Circuit Equipment 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Vegetation 0.00% 0.00% -- 0.00% 0.00% -- -- 0.00% 0.00%
Power System Condition 0.00% 0.00% -- 0.00% 0.00% -- -- 0.44% 0.04%
Human Error 0.00% 0.00% -- 0.00% 0.00% -- -- 0.13% 0.01%
Unknown 0.00% 0.00% -- 0.00% 0.00% -- -- 84.61% 7.24%
Other 0.00% 0.00% -- 0.00% 0.00% -- -- 0.09% 0.01%
TOTAL 100.00% 100.00% -- 100.00% 100.00% -- -- 100.00% 100.00%

Notes:
Detailed information on the Transmission Availability Data System outage causes is available at:
http://www.nerc.com/docs/pc/tadswg/Appendix%207%2020101202a%20clean.pdf
Source: U.S. Energy Information Administration, Form EIA-411, "Coordinated Bulk Power Supply Program Report."