Transformer Impedance Calculator

Calculate transformer percent impedance, fault current contribution, and base impedance conversion.

Nameplate kVA.
kVA
Transformer secondary voltage (line-to-line).
V
Nameplate %Z. Typical: 3-8% for distribution, 5-15% for power.
%

Results

Full Load Current-A
Max Fault Current-kA
Base Impedance-Ω
Actual Impedance-Ω
References: IEEE C57.12; NEC Article 450; NFPA 70E