Short-Circuit & Per-Unit Studies

Combining Utility and Transformer Fault MVA at a Secondary Bus

A utility source and 100 MVA, 11.11% impedance transformer feeding a 13.8 kV bus. The reciprocal combination formula turns 1,200 MVA from the utility and 900 MVA from the transformer into 514.3 MVA at the secondary bus.

More in Short-Circuit & Per-Unit Studies

Line-to-Line Fault at Transformer Secondary Terminals (thumbnail)

Line-to-Line Fault at Transformer Secondary Terminals

Bolted Three-Phase Fault at a 1000 kVA Transformer: 20.1 kA (thumbnail)

Bolted Three-Phase Fault at a 1000 kVA Transformer: 20.1 kA

Impedance Chain from Utility Source to a 13.8 kV Fault (thumbnail)

Impedance Chain from Utility Source to a 13.8 kV Fault