We provided complete design services for a 69kV substation on a new site. The operating voltage is 69kV, but the design accommodates a future increase to 138kV. The ultimate substation consists of two incoming 69kV (future 138kV) transmission lines and two 13.8kV distribution substations via 69kV SF6 breakers and 15/20/22.5MVA transformers. The site layout was a challenge because of the proximity of the substation to a pedestrian/bike path and nature area. Significant landscaping design was necessary to blend the substation into these natural surroundings.

For the Syene Substation, each of the electrical designs included schematics and wiring for the 69kV and 13.8kV breakers; substation transformers and custom control buildings; remote terminal unit (RTU) internal and external panel wiring diagrams with breaker control and indication; protective relaying; a local annunciator; interface with customers’ existing supervisory control systems; site lighting; site grounding; and 125Vdc breaker control, including battery, battery charger, and uninterruptable power source (UPS) systems. We also provided bills of material for each project subsystem, including steel, hardware, cable, bus components, insulators, surge arresters, switching components, control panel components, and LV distribution components.

The Utility’s standard specifications were customized for each project. MGE purchased the major equipment directly. We reviewed the equipment shop drawings and worked with the equipment suppliers to customize the installation package to incorporate installation details and connection wiring diagrams for the pre-purchased equipment.

Civil and structural designs for the substation included site plans, structure and foundation drawings, steel shop fabrication drawings, and transformer oil containment pits.