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SIiORT C,�RCUIT CALCULATIONS <br /> Shortcircuitcalculationswereperformed nthesystemasdefinedontheaccompanyingone <br /> li ia nd orres onding sys m data. <br /> A utility availablc fault currcnt of26, 40A at the 480Y/277V >ervice based on a maximum <br /> future 1000kVA(1203A&480V)scrvicc transformer was usei' for these calculations. T'his <br /> data was obtained from Mark Oens at Snohomish PUD on 10/21/O5. <br /> Thc manual vansfer switches are designed to provide an open transition transfer between <br /> utiliry and gencrator sources so the calculations were based on the assumption they should <br /> ncver be connected in parallel <br /> Motor loads equal to 50%of the full load capacity of switchboard MDS were assumed to be <br /> running at the time of fault and their contribution was facrored inro the calculations. <br /> The calculations �vcre pedormed using a computer program developed by EDSA Micro <br /> Corporation(DOS Vcrsion v26.1 I).'fhe program accepts system data,converLs it ro per unit <br /> impcdances,and simulatcs a fault at each node to determine the equivalent impedance to the <br /> point of fault and the resultant fault curren[gcnerated by the driving��oltage at that point. <br /> Thc calculated fault wrrents are listed in the "Short Circuit Program" printout and in the <br /> equipment evaluation portion of this report. <br /> The data used in this study is included for your verificetion and to serve as a record for this <br /> clectrical systcm. <br /> - 9 - �j <br />