In the MVA Method Short Circuit Calculation tutorial, we have discussed how to calculate the three (3) phase and phase to ground fault currents.

The faults currents for three (3) phase unbalance faults are as follows:

  1. Three (3) Phase Fault

    2. KVA_SC=KVA_1

  2. Phase to Ground Fault

    3. KVA_SC=3/{{1/KVA_1}+{1/KVA_2}+{1/KVA_0}}

  3. Phase to Phase Fault

    4. KVA_SC={sqrt{3}*KVA_1}/2

  4. Phase to Phase to Ground Fault

    5. KVA_SC={sqrt{3}*KVA_1*KVA_0}/{KVA_1+KVA_2+KVA_0}

Using the same example as in the MVA Method Short Circuit Calculation tutorial, we will calculate the

  1. Phase to phase Fault
  2. Phase to phase to Ground Fault