Substation Short Circuit

Get nominal and bolted-fault current in amperes, verify breakers, fuses, and cable ampacity, and reference conductor tables—built for engineers in the field.

Substation Short Circuit helps electrical engineers and technicians estimate available fault current before specifying equipment.

Enter system voltage, transformer kVA and impedance, cable length and size, fault type, and X/R ratio. With one tap, get:

• Symmetrical fault current • Asymmetrical fault current • Peak current • Interrupting rating • Base current and total cable-system impedance

Then check the equipment.

Compare circuit breaker current and interrupting ratings, fuse ratings, and cable ampacity against the calculation. The app flags equipment as adequate or inadequate so you can identify potential issues before specifying gear.

Need conductor data for the same job? Browse the built-in ampacity table for copper and aluminum conductors, common insulation types, temperature settings, and free-air or raceway conditions. View resistance and reactance, then copy conductor details when needed.

Save calculations with a description, search saved jobs later, and load them back into the calculator. Optional iCloud sync keeps saved calculations available across your Apple devices.

Built for the field and office: • English and Spanish • iPhone and iPad • Light and Dark appearance • No ads

Substation Short Circuit is a calculation aid and is not a substitute for a licensed short-circuit study, applicable codes, manufacturer data, or professional engineering judgment.