Table 8.12.A. U.S. Transmission Circuit Sustained Automatic Outage Counts and Hours
by High-Voltage Size and NERC Region, 2013
 

Sustained Automatic Outage Counts
Voltage Region
Type Operating (kV) FRCC MRO NPCC RFC SERC SPP TRE WECC Contiguous U.S.
AC 0-99 -- -- -- -- -- -- -- -- --
AC 200-299 113 96 25 90 194 56 -- 406 980
AC 300-399 -- 89 93 85 37 60 80 174 618
AC 400-599 4 1 -- 23 84 -- -- 143 255
AC 600+ -- -- 4 11 -- -- -- -- 15
AC Total   117 186 122 209 315 116 80 723 1,868
DC 0-99 -- -- -- -- -- -- -- -- --
DC 100-199 -- -- -- -- -- -- -- -- --
DC 200-299 -- 6 -- -- -- -- -- -- 6
DC 300-399 -- -- -- -- -- -- -- -- --
DC 400-499 -- 3 -- -- -- -- -- -- 3
DC 500-599 -- -- -- 5 -- -- -- 16 21
DC 600+ -- -- -- -- -- -- -- -- --
DC Total   -- 9 -- 5 -- -- -- 16 30
Grand Total   117 195 122 214 315 116 80 739 1,898

 

Total Outages per 1,000 Circuit Miles
  Region
  FRCC MRO NPCC RFC SERC SPP TRE WECC Contiguous U.S.
Rate   16.21 11.13 16.10 8.47 9.19 13.90 8.40 11.49 10.90

 

Sustained Automatic Outage Hours
Voltage Region
Type Operating (kV) FRCC MRO NPCC RFC SERC SPP TRE WECC Contiguous U.S.
AC 0-99 -- -- -- -- -- -- -- -- --
AC 200-299 778 1,288 9,072 3,052 2,194 366 -- 3,316 20,067
AC 300-399 -- 2,889 10,497 9,302 424 2,111 1,937 370 27,528
AC 400-599 25 4 -- 8,067 2,320 -- -- 2,438 12,853
AC 600+ -- -- 15 663 -- -- -- -- 678
AC Total   803 4,181 19,584 21,084 4,937 2,477 1,937 6,125 61,127
DC 0-99 -- -- -- -- -- -- -- -- --
DC 100-199 -- -- -- -- -- -- -- -- --
DC 200-299 -- 125 -- -- -- -- -- -- 125
DC 300-399 -- -- -- -- -- -- -- -- --
DC 400-499 -- 10 -- -- -- -- -- -- 10
DC 500-599 -- -- -- 23 -- -- -- 49 72
DC 600+ -- -- -- -- -- -- -- -- --
DC Total   -- 134 -- 23 -- -- -- 49 206
Grand Total   803 4,315 19,584 21,108 4,937 2,477 1,937 6,173 61,333

 

Outage Hours per Outage Incident
  Region
  FRCC MRO NPCC RFC SERC SPP TRE WECC Contiguous U.S.
Rate   6.86 22.13 160.52 98.63 15.67 21.35 24.21 8.35 32.31

Notes:
* = Value is less than half of the smallest unit of measure. (e.g., for values with no decimals, the smallest unit is 1 then values under 0.5 are shown as *.)
Circuit Miles for each region is displayed in Table 8.10.A.
An Automatic Outage is an outage which results from the automatic operation of a switching device, causing an Element to change from an In-Service State to a not In-Service State.
A Sustained Outage is an automatic outage with an outage duration of a minute or greater.
Source: U.S. Energy Information Administration, Form EIA-411, "Coordinated Bulk Power Supply Program Report."