Fault Current
Keeping It Simple
During facility design, engineers must calculate electrical fault currents and ensure all electrical equipment can withstand them. Many factors enter into the calculation: transformer size and impedance, wire size and type, conductor lengths, parallel conductors, percent of load powering motors. Once calculated during facility design, there is not much need to do more. The developed values are used to select proper electrical equipment. That said, there may be times a renovation or expansion adds electrical equipment and knowing fault current levels may be helpful. To help we added a fault current feature to Power System Pathways, keeping the KISS Principle (Keep It Simple Silly) in mind.
Fault current originates at the transformer supplying a circuit. The value decreases due to wiring after the transformer and the value increases when motors are part of the load. Worst case is relatively simple and quick to calculate. We added an "approximator" to provide worst case transformer fault current values for Power System Pathway users. Admittedly most users won't use this feature but those that want it can be comforted of this addition.