Overhead Transmission Line. Number of Circuits: 1 Nominal Phase to Phase Voltage: 230kV Line Terminus 1: IID El Centro Switching Station 230kV Bus Bus Configuration: Ring bus or breaker and a half (BAAH) Line Terminus 2: SDG&E Imperial Valley 230kV Bus Bus Configuration: Breaker and a half (BAAH) 1 El Centro Switching Station Upgrades; IID shall undertake El Centro Switching Station upgrades by installation of Bank No. 5 transformation that will include a 332 MVA 230/92kV transformer. These upgrades shall be at the sole cost of IID, with neither the CAISO nor Citizens having any responsibility for the cost of these upgrades. The incremental capacity in the S-Line created by the El Centro Switching Station Upgrades shall be shared as set forth below. Minimum Line Continuous Ampacity – Summer: 1,757 Amps (~700 MVA) Minimum Line Continuous Ampacity – Winter: 1,757 Amps (~700 MVA) Minimum Line 4 Hour Emergency Ampacity – Summer: 1,757 Amps (~700 MVA) Minimum Line 4 Hour Emergency Ampacity – Winter: 1,757 Amps (~700 MVA) Minimum Line 30 Minute Emergency Ampacity – Summer: 2,134 Amps (~850 MVA) Minimum Line 30 Minute Emergency Ampacity – Winter: 2,134 Amps (~850 MVA) Approximate Line Impedance: resistance: .0015 to .002, reactance: .018 to .022 per unit on a 100 MVA base. Maximum Line Resistance: .002 per unit on a 100 MVA base Approximate Line Length: 18.1 miles Preliminary In Service Date: April 27, 2023 Support Structures: Steel Shield Wire Requirement: Optical ground wire (minimum 6 pairs of fibers) Failure Containment Loading Mitigation (anti-cascade structures, etc.): Per applicable codes Shield Wire Ground Fault Withstand Ampacity: Coordinate with interconnecting entities Aeolian Vibration Control (Conductor and Shield Wire): Vibration dampers must be installed on all conductors and overhead shield wires, with the exception of slack spans Transmission Line Minimum BIL: 1,050kV (900kV for solidly grounded systems) Minimum ROW Width: Per applicable codes Governing Design and Construction Standards: GO 95, NESC Code, applicable municipal codes Citizens will contract with IID to have IID make reasonable efforts to have construction started no later than July 1, 2021. Governing Design and Construction Standards: NESC Code, applicable municipal codes *Milestone date per Appendix E
Overhead Transmission Line. An approximate 0.25-mile long overhead 500 kV transmission line will extend from the project substation to the point of interconnection with the existing BA transmission system at the BPA Wautoma substation.
