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

  3. Phase to Ground Fault
  4. KVA_SC=3/{{1/KVA_1}+{1/KVA_2}+{1/KVA_0}}

  5. Phase to Phase Fault
  6. KVA_SC={sqrt{3}*KVA_1}/2

  7. Phase to Phase to Ground Fault
  8. 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

Author

  • A Filipino Engineer, Registered Professional Engineer of Queensland (RPEQ) - Australia, and Professional Electrical Engineer (PEE 2574 - 1st Place April 1991) - Philippines with extensive experience in concept selection, front-end engineering, HV & LV detail design, construction, and commissioning of Hazardous and Non-Hazardous Area electrical installations in water and wastewater pipeline and pumping facilities, offshore platforms, hydrocarbon process plants and pipelines including related facilities. Hazardous area classification and design certification (UEENEEM015B, UEENEEM016B, UEENEEM017B).