Use this engineering calculation for a transparent preliminary estimate or independent arithmetic check when geometry, materials, loads, operating conditions, and units are defined consistently.

Line Voltage Kilovolts (kV)

Required number input.

Fault Current Kiloamperes (kA)

Required number input.

Balanced three-phase fault apparent power in MVA from line-to-line voltage in kV and fault current in kA. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Fault Mega Volt Amperes (MVA)

The resulting fault mega volt amperes returned as a number.

• Electrical estimates require the correct AC or DC model, RMS and phase conventions, source impedance, grounding, conductor conditions, protection, temperature, harmonics, faults, and applicable standards. Nominal ratings are not automatically compatible design limits.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check assumptions against drawings, measurements, current material data, and the applicable design code. Apply required load combinations and safety factors, then obtain qualified review and testing for consequential designs.

• Three Phase Apparent Power

  Balanced three-phase apparent power √3 VLL I at line-to-line RMS voltage.

• Three Phase Active Power

  Balanced three-phase active power √3 VLL I cosφ at line-to-line RMS voltage.

• Short Circuit Current

  Ideal prospective short-circuit RMS current from source RMS voltage and total fault-loop impedance magnitude.