Fault: Current Calculation

One phase touches the ground. This is the most common type of fault in the field.

Circuit breakers and fuses must be rated to "break" the maximum possible fault current. If a breaker is rated for 10kA but the fault is 20kA, the breaker may explode rather than trip. fault current calculation

The following steps are involved in calculating fault currents: One phase touches the ground

[ I_f \approx \fracV_thX_th ]

Fault currents are calculated using per-unit (pu) quantities to simplify transformer and voltage level conversions. fault current calculation