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SOLGr- N <br /> P O W E R <br /> Lag Screw Calculation (per ASCE 7-16 Ch. 30 and NDS) <br /> This calculation justifies the connection of the solar panels to existing roof members, by showing the <br /> connection capacity is equal to or greater than the uplift force demands. <br /> Connection Demand <br /> Spacing perpendicular to rail 32.5 in 1/2 panel length <br /> Spacing parallel to rail 48 in Max spacing <br /> Effective Wind Area on each connection 10.8 ft2 <br /> Roof Angle 24 degrees <br /> Wind Speed 100 mph <br /> Exposure Coefficient, KZ 0.86 <br /> Topographic Factor, KZt 1 <br /> Directionality Factor, Kd 0.85 <br /> Elevation Factor, Ke 0.97 <br /> Velocity Pressure, qZ 18.2 psf <br /> Prying Coefficient 1 <br /> Zones 1, 2e Zones 2n, 2r, 3r Zone 3e <br /> GCp (max) 1.5 2.5 3.6 <br /> Exposed Panels? NE = 1.5) No Yes Yes <br /> Pressure Equalization Factor, ya 0.79 0.79 0.79 <br /> Uplift Force 21.4 53.5 77.1 psf <br /> Max. Uplift Force/ Connection (0.6 WL) 139.2 348.0 501.1 lbs <br /> Solar Dead Load (0.6 DL) 17.0 17.0 17.0 lbs <br /> Max. Uplift Force (0.6 WL- 0.6 DL) 122.2 331.0 484.1 Ibs <br /> Connection Capacity <br /> Fastener Type Lag Screw <br /> Fastener Diameter 0.3125 in <br /> Embedment Length, min 1.5 in <br /> Lumber Species & Grade DFL#2 (Assumed) <br /> Lumber Specific Gravity 0.5 <br /> Nominal Withdrawal Capacity, W 399.0 Ibs NDS 12.2-1 <br /> #of Screws 1 <br /> Load Duration Factor, CD 1.6 <br /> (Note:CM=Ct=Ceg=1.0) <br /> Adjusted Withdrawal Capacity, W' 638.4 Ibs <br /> Compare Adiusted Withdrawal Capacity to ASD Factored Demand <br /> Zones 1, 2e Zones 2n, 2r, 3r Zone 3e <br /> 0.K. O.K. 0.K. <br />