Available Fault Current Formula Extra Quality (100% FULL)

Uses the utility's available fault current at the service point. $$I_total = \fracV_LL\sqrt3 \cdot (Z_utility + Z_transformer)$$

| Scenario | Use Formula # | | :--- | :--- | | Rough estimate, no data | #2 (Transformer only) | | You know utility fault current | #3 (Limited Utility) | | Motors > 50 HP present | #4 (Add motor contribution) | | Fault is 100+ ft from transformer | #5 (Include conductor) | | Formal study for arc flash | #6 (Point-to-Point or IEEE 1584 software) | available fault current formula

The basic formula is:

$$I_sc = \frac500 \times 1000480 \times 1.732 \times 0.05 \approx 12,028 \text Amps$$ Uses the utility's available fault current at the