| Table 8.12.A. U.S. Transmission Circuit Sustained Automatic Outage Counts and Hours |
| by High-Voltage Size and NERC Region, 2011 |
| Sustained Automatic Outage Counts | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Voltage | Region | |||||||||
| Type | Operating (kV) | FRCC | MRO | NPCC | RFC | SERC | SPP | TRE | WECC | Contiguous U.S. |
| AC | 200-299 | 116 | 65 | 12 | 153 | 276 | 58 | -- | 488 | 1,168 |
| AC | 300-399 | -- | 64 | 73 | 105 | 69 | 60 | 132 | 228 | 731 |
| AC | 400-599 | 5 | 5 | -- | 16 | 117 | 1 | -- | 123 | 267 |
| AC | 600+ | -- | -- | 2 | 12 | -- | -- | -- | -- | 14 |
| AC Total | 121 | 134 | 87 | 286 | 462 | 119 | 132 | 839 | 2,180 | |
| DC | 100-199 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| DC | 200-299 | -- | 20 | -- | -- | -- | -- | -- | 2 | 22 |
| DC | 300-399 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| DC | 400-499 | -- | 7 | -- | -- | -- | -- | -- | -- | 7 |
| DC | 500-599 | -- | -- | -- | 6 | -- | -- | -- | 9 | 15 |
| DC | 600+ | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| DC Total | -- | 27 | -- | 6 | -- | -- | -- | 11 | 44 | |
| Grand Total | 121 | 161 | 87 | 292 | 462 | 119 | 132 | 850 | 2,224 | |
| Total Outages per 1,000 Circuit Miles | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Region | ||||||||||
| FRCC | MRO | NPCC | RFC | SERC | SPP | TRE | WECC | Contiguous U.S. | ||
| Rate | 16.99 | 7.67 | 12.75 | 11.49 | 13.89 | 15.34 | 13.89 | 13.71 | 12.87 | |
| Sustained Automatic Outage Hours | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Voltage | Region | |||||||||
| Type | Operating (kV) | FRCC | MRO | NPCC | RFC | SERC | SPP | TRE | WECC | Contiguous U.S. |
| AC | 200-299 | 1,651 | 7,043 | 91 | 9,220 | 11,860 | 421 | -- | 6,686 | 36,972 |
| AC | 300-399 | -- | 3,206 | 10,484 | 5,626 | 2,774 | 685 | 1,909 | 1,114 | 25,797 |
| AC | 400-599 | 24 | 11 | -- | 11,874 | 14,909 | * | -- | 1,071 | 27,889 |
| AC | 600+ | -- | -- | 4 | 185 | -- | -- | -- | -- | 189 |
| AC Total | 1,675 | 10,260 | 10,579 | 26,906 | 29,543 | 1,106 | 1,909 | 8,870 | 90,847 | |
| DC | 100-199 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| DC | 200-299 | -- | 252 | -- | -- | -- | -- | -- | 6 | 258 |
| DC | 300-399 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| DC | 400-499 | -- | 272 | -- | -- | -- | -- | -- | -- | 272 |
| DC | 500-599 | -- | -- | -- | 358 | -- | -- | -- | 299 | 657 |
| DC | 600+ | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| DC Total | -- | 524 | -- | 358 | -- | -- | -- | 305 | 1,187 | |
| Grand Total | 1,675 | 10,784 | 10,579 | 27,264 | 29,543 | 1,106 | 1,909 | 9,175 | 92,034 | |
| Outage Hours per Outage Incident | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Region | ||||||||||
| FRCC | MRO | NPCC | RFC | SERC | SPP | TRE | WECC | Contiguous U.S. | ||
| Rate | 13.84 | 66.98 | 121.59 | 93.37 | 63.95 | 9.29 | 14.46 | 10.79 | 41.38 | |
| 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." |