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Transformer Support Calculations <br />Demand <br />H =40 in Max height of unit <br />L1 =36 in Length of unit <br />L2 =24 in Width of unit <br />W p =400 lbs Component weight <br />SDS =1.052 Short period spectral acceleration <br />ap =1 Component amplification factor Fp =0.34 *W p <br />Rp =2.5 Component response modification factor <br />Ω0 =2 Overstrength factor <br />Ip =1 Component importance factor Fp,max =1.68 *W p <br />z = 16.5 ft Elevation above base <br />h = 33 ft Average roof height <br />Fp =134.7 lbs Seismic design force Fp,min =0.32 *W p <br />Fv =84.2 lbs Vertical seismic demand <br />Transformer Anchorage <br />yCOG =26.7 in Unit center of gravity assumed at 2/3H <br />OMu =3591 lb-in Overturning moment demand <br />nanchors=4 Total number of anchors <br />T/C = 74.8 lbs Tension compression demand in each anchor due to lateral seismic demand <br />V =34 lbs Shear demand on each anchor due to lateral seismic demand <br />Fnt =45 ksi Nominal tensile strength of bolt <br />Fnv =27 ksi Nominal shear strength of bolt <br />Dbolt =0.5 in Diameter of bolt <br />Abolt =0.20 in 2 Area of bolt <br />frv =0.2 ksi Required shear stress of connection <br />F'nt =45 ksi Adjusted nominal tensile sress <br />ɸRn =6.6 kips Tensile capacity of bolt with effects from shear included <br />O.K. <br />P1000 Beams <br />L =36 in Span of unistrut supporting transformer <br />nb =2 Number of members supporting unit <br />Pmax,t =564 lbs Maximum gravity demand from unit (acts on min (2) members) <br />Pmax,m =282 lbs Maximum gravity demand on member <br />Mmax =2536 lb-in Maximum flexural demand on section (Worst case demand at midspan) <br />Mall =5070 lb-in Allowable flexural capacity of section per catalog <br />O.K. <br />PROJECT <br />CLIENT <br />LOCATION <br />ITEM <br />McGuff TI <br />KPRS Inc <br />Santa Ana, CA <br />Transformer <br />S24-0254 <br />SHEET # <br />ENGINEER <br />DATE <br />JOB # <br />3/12/2025 <br />C. Landis <br /> BRANDOW & JOHNSTON STRUCTURAL & CIVIL ENGINEERS | LOS ANGELES NEWPORT BEACH