Planning with SIVACON 8 PS - Siemens

Further information about planning7.1 Dimensioning and selectionThe tripping characteristic of the protective device must be selected as appropriate for theshort-circuit rating of the busbar system, the type of system, the type and number of loads,as well as in line with country-specific regulations and type series. We recommend using adimensioning program such as SIMARIS design to assist you in making this selection.7.1.3 Loop impedanceAs the level of loop impedance is decisive as regards the magnitude of the single-poleshort-circuit current, DIN VDE 0100-610 prescribes that loop impedance must be determinedbetween:● Phasel conductor and protective conductor or● Phase conductor and PEN conductorThe value can be determined by means of:● Measurements taken using measuring instruments● Calculation● Simulating the network in the network modelImpedance values for the BD2A/BD2C, LDA/LDC, LXA/LXC and LRC busbar trunkingsystems are listed in the "Technical data" section; these can be used to calculate the loopimpedances of a busbar system forming part of the total loop impedance.The minimum anticipated single-pole short-circuit current can be calculated easily based onthe loop impedance of the entire busbar trunking system.c = voltage factor 0.95UnZk= voltage between phase conductors= short-circuit impedanceCalculating the loop impedance of all contributory equipment in a system (incoming powersupply, transformers, distribution boards, cable runs, etc.) takes a great deal of time andeffort. In this regard, planning time and effort can be reduced significantly by using adimensioning program such as SIMARIS design which stores the necessary data for mostcommon electrical equipment in a database.Planning with SIVACON 8 PS238 Planning Manual, 10/2007, A5E01541101-01