Stages of Construction

Stage 1: Temporary Transmission line SF-1A relocation and temporary transmission line lift structure installation. Phases 1-4

Stage 2: 230kV switchyard construction. Phases 2-5

Stage 3: Transfer existing S61 230kV transmission lines. Phases 6-17

Stage 4: 115kV switchyard construction. Phases 13-18

Stage 5: Transfer existing S61 115kV transmission lines. Phases 19-25

Stage 6: Demolition of old S61 115kV and 230kV switchyards. Phase 26

Stage 7: Transfer existing S106 Plant 115kV lines. Phases 27-28

Stage 8: Distribution substation. Phases 29-31

Tortoise Relocation

Clearing & Grubbing

PHASE 1

Temporary Transmission Lift Structure installation (Staged Outages)

230kVs line – Lift Structure

• De-energize existing 230kVs line
• Install new temp. lift structure
• Transfer existing 230kV line from existing tangent structure to new lift structure
• Remove existing 230kV line tangent structure
• Re-energize 230kV line

230kV line – Lift Structure

• De-energize 230kV line
• Install new temp. lift structure
• Relocate existing 230kV line to new lift structure
• Re-energize 230kV line

115kV Flyover – Lift Structure

• De-energize 115kV flyover line
• Install new temp. lift structure
• Re-locate existing 115kV flyover line to new lift structure
• Re-energize 115kV flyover line

Phase 2

• Clear/grub existing trees
• Begin 230kV switchyard grading
• De-energize existing capacitor bank
• Remove cap bank, reactors, BKR 3539, DISC switch
• Demo foundations of removed equipment
  (Space is required to construct new CEE & Bank #1 230kV bus)

Phase 3

• Construction of 115kV temp. shoe-fly line in progress

Phase 4

• De-energize existing 115kV line
• Install fiber optic cable from new transmission line structure 118R4 on line to level 3 telecom building
• Remove first spans of 115kV line
• Complete construction of 115kV shoe-fly and fiber connections
• 115kV switchyard grading to be completed

Phase 5

• Construction of new CEE in progress
• Construction of new 230kV switchyard in progress
• Installation of 230kV bank #1 strain bus in progress
• Install three 115kV 100KVA SSVTs for temp. station power to sub #538 in existing sub #61
• Extend 13kV distribution feeder and install six 13kV 100KVA distribution transformers for backup station power to sub #538
• At the end of phase 5 new 230kV switchyard/CEE construction complete and functioning
(Existing 230kV line in-service may effect construction activities directly under line)

Phase 6

• De-energize existing 230kV line
• Reroute first span of 230kV line

Phase 7

• Construction of new 230kV line and S61 tie #1 line in progress
• Install temp. fiber cable between substations #61 and #538
• New 230kV line, 230kV bus #3 & #4, and S61 tie #1 line cut into new 230kV switchyard then energized

Phase 8

• New 230kV switchyard capacitor banks #3 & #4 to be energized

Phase 9

• De-energize existing 230kV line
• Reroute first span of existing 230kV line

Phase 10

• Construction of new 230kV line and S61 tie #2 line in progress
• New 230kV line and S61 tie #2 line cut ionto new 230kV switchyard then energized

Phase 11

• De-energize existing 230kV line
• Open sub #61 disconnect switch, de-energize existing bus to line a-frame dead-end tower
• Remove first two spans of existing 230kV line
• Reroute existing 230kV Strain bus and a-frame dead-end tower
• Remove temp. lift structure and SF2-1 tower
(Existing 230kV line outage needed)

Phase 12

• Construction of new 230kV line in progress
• New 230kV line cut into 230kV switchyard then energized including 230kV bus #1 & #2

Phase 13

• Construction of new 115kV switchyard in progress
(115kV flyover line is in-service - may effect construction activities directly under line)

Phase 14

• De-energize existing 230kV line
• Reroute of the existing 230kV line
• Remove temp. lift structure and existing S-61-7 structure
• Remove existing sub 61 230kV line dead-end structure and PT's
• Demo existing sub 61 230kV line dead-end structure and PT's foundations
(Existing 230kV line crosses over the new 230kV switchyard)

Phase 15

• Construction of 230kV line and completion of bank #1 230kV bus in progress
• Installation of fiber cable tos line structure S-61-4 from sub #538 CEE in progress
• Installation of transformer bank #1 & #2 in progress
• Installation of 115kV bank #2 strain bus in progress
(230kV line crosses over CAP BANK #2))

Phase 16

• New 230kV line cut into new 230kV switchyard then energized

Phase 17

• New 230kV switchyard capacitors #1 & #2 to be energized

Phase 18

• New 115kV switchyard construction complete and functional testing complete
• Energize 230/115kV Bank #1
• Energize 115kV switchyard
• Energize 230/115kV Bank #2
• Energize 3 115kV 100kVA SSVTs located in sub #538 and cut into sub #538 station power system
• Relocate 3 115kV 100kVA SSVTs from temp. location in sub #61 to permanent location in sub #538 and cut into sub #538 station power system

Phase 19

• De-energize existing 115kV SF-1A line
• Remove 3 spans of existing 115kV SF-1A line
• Construction of 115kV STCX-1 line in progress
• Fiber cable installation from new sub #538 line terminal to level 3 telecom building in progress
(Re-use spans of temp. shoe-fly for plant S106 tie line SST1-1)

Phase 20

• New 115kV line cut into new 115kV switchyard, fiber reconnected, and line energized from sub #538
• Re-use two spans of shoe-fly temp. reroute for S106 tie line SST1-1

Phase 21

• Complete installation of 115kV temp. plant S106 tie line SST1-1 (including OPGW), except for tying into existing 115kV SF-2 line
• Install fiber cable from SST1-1 sub #538 terminal to new CEE and to level 3 telecom building
• Install fiber cable from new SF-2 sub #538 terminal to new CEE and level 3 telecom building
• De-energize existing 115kV SF-2 line
• Install new SST1-1 structure and cut SST1-1 tie line phase and OPGW into existing SF-2 line
• Complete fiber path from Plant to sub #538 CEE; Install 311L relay at Plant for SST1-1 tie line relay protection
• Remove existing SF-2 line from structure SST1-1 to sub #61
• Remove existing SF-2 line from sub #61 to existing structure SF-5
• Remove SF-2 temp. lift structures
• Complete installation of SF-2 line into new substation terminal in sub #538

Phase 22

• New 115kV SF-2 line and 115kV Plant S106 tie line SST1-1 cut into new 115kV switchyard then energized

Phase 23

• De-energize existing 115kV Occidental line
• Reroute of the existing 115kV (Occidental) line
• Construction of 115kV Occidental line (including OPGW) into new sub #538 terminal in progress
• Install fiber cable from new sub #538 terminal in to new CEE and to level 3 telecom building
• Existing SSC-1 to be removed

Phase 24

• New 115kV Occidental line cut into new sub #538 115kV switchyard then energized

Phase 25

• De-energized existing 115kV Plant line
• Remove existing Plant line SF-1 and all transmission structures

Phase 26

• De-energize 230kV S61 tie #1 and S61 tie #2 lines
• De-energize existing sub #61 115kV and 230kV switchyards
• Demo one span of the S61 tie #1 and S61 tie #2 lines and supporting guy wires.
• Demo existing sub #61 115kV and 230kV switchyards

Phase 27

• 115kV SUM-1 line outage

Phase 28

• 115kV SP-1 line outage

Phase 29

• 115kV Hanson SW-1 line outage

Phase 30

• 115kV Jasper SW-2 line outage

Phase 31

• De-energize 115kV Occidental line
• Cut 115kV Occidental line into new 115/13kV distribution substation #539 115kV switchyard

Phase 32

• Re-energize 115kV Occidental line
• Energize new 115/13kV distribution substation
• Energize distribution substation #539 115/13kV transformer banks #1 and #2 and 13kV switchyard
• Transfer 13kV distribution load from plant sub #106 to new 115/13kV distribution sub #539

Phase 33

• After distribution load removed from plant substation, de-energize temporary 115kV plant tie line
• Demo temporary 115kV plant tie line
• Plant substation #106 ready for demolition

Phase 34

Construction Complete