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Prospective Fault Current Calculator
Calculate the maximum prospective fault current (PFC) in electrical installations using supply voltage and loop impedance. Compliant with BS 7909 and electrical safety standards.
⚡ Electrical safety
📊 Precise calculations
✓ BS 7909 compliant
PFC Calculator
Calculate prospective fault current
Supply Parameters
V
Phase-to-neutral voltage (single phase) or phase-to-phase (3-phase)
Single or three-phase system
Loop Impedance
Ω
External loop impedance from supply to fault point
Ω
Impedance of circuit conductors (leave 0 if included in Ze)
Additional Options
Standard method for PFC calculation
Fault Current Results
Prospective fault current at the point of installation
Enter your supply voltage, system type, and loop impedance, then click Calculate to determine the prospective fault current.