Table 8.12.A. U.S. Transmission Circuit Sustained Automatic Outage Counts and Hours
by High-Voltage Size and NERC Region, 2012
 

Sustained Automatic Outage Counts
Voltage Region
Type Operating (kV) FRCC MRO NPCC RFC SERC SPP TRE WECC Contiguous U.S.
AC 200-299 142 49 14 141 242 49 -- 484 1,121
AC 300-399 -- 88 107 95 46 56 80 165 637
AC 400-599 9 3 -- 22 86 -- -- 125 245
AC 600+ -- -- 6 9 -- -- -- -- 15
AC Total   151 140 127 267 374 105 80 774 2,018
DC 100-199 -- -- -- -- -- -- -- -- --
DC 200-299 -- 18 -- -- -- -- -- 5 23
DC 300-399 -- -- -- -- -- -- -- -- --
DC 400-499 -- 5 -- -- -- -- -- -- 5
DC 500-599 -- -- -- 5 -- -- -- 17 22
DC 600+ -- -- -- -- -- -- -- -- --
DC Total   -- 23 -- 5 -- -- -- 22 50
Grand Total   151 163 127 272 374 105 80 796 2,068

 

Total Outages per 1,000 Circuit Miles
  Region
  FRCC MRO NPCC RFC SERC SPP TRE WECC Contiguous U.S.
Rate   21.08 7.54 18.90 10.69 11.01 13.03 8.29 12.63 11.77

 

Sustained Automatic Outage Hours
Voltage Region
Type Operating (kV) FRCC MRO NPCC RFC SERC SPP TRE WECC Contiguous U.S.
AC 200-299 823 256 7,832 10,033 4,672 494 -- 13,264 37,374
AC 300-399 -- 835 6,386 5,892 1,080 1,016 683 578 16,468
AC 400-599 2,030 15 -- 1,825 1,372 -- -- 10,087 15,328
AC 600+ -- -- 28 2,089 -- -- -- -- 2,117
AC Total   2,852 1,106 14,245 19,839 7,124 1,510 683 23,930 71,287
DC 100-199 -- -- -- -- -- -- -- -- --
DC 200-299 -- 127 -- -- -- -- -- 44 171
DC 300-399 -- -- -- -- -- -- -- -- --
DC 400-499 -- 80 -- -- -- -- -- -- 80
DC 500-599 -- -- -- 19 -- -- -- 264 283
DC 600+ -- -- -- -- -- -- -- -- --
DC Total   -- 207 -- 19 -- -- -- 308 534
Grand Total   2,852 1,313 14,245 19,857 7,124 1,510 683 24,239 71,822

 

Outage Hours per Outage Incident
  Region
  FRCC MRO NPCC RFC SERC SPP TRE WECC Contiguous U.S.
Rate   18.89 8.06 112.16 73.00 19.05 14.38 8.53 30.45 34.73

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."