Fault Current Calculator (PFC)

Fault Current Calculator for iPhone and iPad is a fast, free tool for electricians, contractors, and engineers. Calculate Prospective Fault Current (PFC), Prospective Short-Circuit Current (PSCC), and Prospective Earth Fault Current (PEFC).

Enter any two known values - voltage, loop impedance (Zs/Ze), or fault current - and the app instantly calculates the third.

KEY FEATURES:

PSCC and PEFC calculations:
Calculate prospective short-circuit current for L-N or L-L faults and prospective earth fault current for L-E faults.

Single-phase and three-phase support: Perform fault-current calculations for both system types.

Automatic calculations:
Enter any two known values to auto calculate the third.

Loop-impedance calculator:
Calculate Zs or Ze from voltage and prospective fault current.

Formula display:
See the formula used for each calculation so you can understand and verify the result.

Works offline:
Use the app in roof spaces, basements, plant rooms, and other locations without a signal.

Dark mode and light mode:
Maintain a clear display in different site conditions.

16 languages:
Fully translated for electricians worldwide (af, ar, de, es, en, fr, hi, id, it, ja, ko, nl, pl, pt, ru, zh).

Fast and free:
A clean interface designed to deliver results without unnecessary steps.

DEFINITIONS:
AIC (Ampere Interrupting Capacity), often written as kAIC for kilo-Amperes, is a specific rating for protective devices that open a circuit, such as circuit breakers and fuses.

SCCR (Short-Circuit Current Rating) is the maximum fault current that a complete piece of equipment or electrical assembly (like an industrial control panel, switchboard, or HVAC unit) can safely withstand without causing a hazard.

Electrical calculations should be independently verified before safety-critical work. Ensure the calculated prospective fault current does not exceed the protective device's rated breaking capacity.

For additional tools, upgrade to Electrical Tools & Reference, which includes calculators for kVA, Max Zs, cable sizing, and more.

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