Ogden, Utah
Spectrum Engineers was the prime consultant and provided electrical and power engineering for this 7.5 MVA, 46 kV – 12.5 kV substation supporting the electrical needs of the new, $180-million, 690,000 sq. ft. McKay-Dee Medical Center. Spectrum also provided emergency generation design. This substation is designed to withstand a seismic zone 4 earthquake due to the critical nature of the load being served and because early geotechnical investigations revealed extensive underlay deposits that might become susceptible to significant total and differential movements during a major earthquake. A monolithic pad was designed to support substation equipment, which allows the entire substation to move as one while retaining critical alignments because it allows for “give” with the earth. During a seismic event, the pad’s greater surface area is much less likely to tilt than individual foundations, even those with drilled piers, and is designed to ensure operation of the medical center.