Short Circuit Analysis is performed to determine the currents that flow in a power system under fault conditions. If the short circuit capacity of the system exceeds the capacity of the protective device, a dangerous situation exists. Since growth of a power system often results in increased available short-circuit current, the momentary and interrupting rating of new and existing equipment on the system must be checked to ensure the equipment can withstand the short-circuit energy. Fault contributions for utility sources, motors and generators are taken into consideration. The results of a Short Circuit Analysis are also used to selectively coordinate electrical protective devices.