| Table 8.12.B. U.S. Transformer Sustained Automatic Outage Counts |
| and Hours by High-Voltage Size and NERC Region, 2011 |
| Sustained Automatic Outage Counts | ||||
|---|---|---|---|---|
| High-Side Voltage (kV) |
Eastern Interconnection | TRE | WECC | Contiguous U.S. |
| 100-199 | -- | -- | -- | -- |
| 200-299 | -- | -- | -- | -- |
| 300-399 | 10.00 | -- | 1.00 | 11.00 |
| 400-599 | 19.00 | -- | 3.00 | 22.00 |
| 600+ | 2.00 | -- | -- | 2.00 |
| Grand Total | 31.00 | -- | 4.00 | 35.00 |
| Sustained Automatic Outage Hours | ||||
|---|---|---|---|---|
| High-Side Voltage (kV) |
Eastern Interconnection | TRE | WECC | Contiguous U.S. |
| 100-199 | -- | -- | -- | -- |
| 200-299 | -- | -- | -- | -- |
| 300-399 | 505.53 | -- | 14.27 | 519.80 |
| 400-599 | 24,652.62 | -- | 68.97 | 24,721.59 |
| 600+ | 18.48 | -- | -- | 18.48 |
| Grand Total | 25,176.64 | -- | 83.23 | 25,259.87 |
| Outage Hours per Outage Incident | ||||
|---|---|---|---|---|
| Eastern Interconnection | TRE | WECC | Contiguous U.S. | |
| Rate | 812.15 | -- | 20.81 | 721.71 |
| 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 *.) Eastern NERC Regions are aggregated to preserve confidentiality. 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." |