Description:

Tolono Substation is a new 5MVA distribution substation designed for one of Prairie Power’s members, Eastern Illini Electric Cooperative. The substation includes a 69kV A-frame dead-end, new 5MVA transformer, mobile substation hookup, and an eight-position distribution box-bay structure. The transformer was protected by fuses mounted to the 69kV A-frame. The distribution feeders were protected by either triple-single or hydraulic reclosers, depending on the type of load. Feeders exited the station through underground conduit. To prevent the occurrence of single-phasing sensitive three-phase motor load in the area, a main bus recloser was included to trip out the distribution bay in the event of a 69kV fuse blowing. The substation also included a pre-fabricated concrete building that housed the feeder-level metering, AMR controller, and SCADA equipment.

Tasks performed include site grading design, foundation design, facilitation of steel structure design & procurement, bus design, major material selection & procurement, ground grid design & safety analysis, conduit system design, lightning protection design, yard lighting design, construction contract administration, field observation during construction, and station commissioning.