Description:

Toth and Associates provided electrical engineering design for the construction of Oregon Trail Substation on Umatilla Electric Cooperative’s system in Hermiston, Oregon. The existing station was a 25 MVA 115/12.47 kV distribution substation. The high‐side of the station was configured as a feed‐through transmission bus. The low‐side of the station was configured as a main and transfer bus arrangement with an ultimate configuration of two 15/20/25 MVA transformers and a total of six distribution bays in addition to a tie breaker. Three distribution feeders exit the substation via overhead lines and one existing overhead transmission line leaves the station to the west.

This project included the installment of the second 115kV line breaker for installation of the second transmission line to Buttercreek North Substation. Additional work included the installation of non‐rigid jumpers to the existing switches, fit up of new above‐grade conduits to existing below‐grade conduits, breaker grounding connections via existing ground grid risers, installation/termination of new low voltage wiring, and site clean‐up. New low voltage wiring was installed in existing conduits/raceways to the 115kV circuit breaker from all control building locations.