Checks per-phase load balance across a 3-phase distribution board/panel and computes the resulting neutral current, using the standard three-phase unbalanced-current phasor formula (currents 120° apart).
Standards followed
Standard three-phase unbalanced-current phasor formula: In = √(IL1²+IL2²+IL3²−IL1·IL2−IL2·IL3−IL1·IL3)
What it can do
- Average phase current and maximum percentage deviation from average.
- Identifies the most- and least-loaded phase.
- Neutral current from the phasor formula (not a simple arithmetic difference).
Example problem
IL1=45A, IL2=38A, IL3=52A.
- Average = (45+38+52)/3 = 45A.
- In = √(45²+38²+52²−45×38−38×52−45×52) = √(2025+1444+2704−1710−1976−2340) = √147 ≈ 12.12A.
≈12.1A neutral current.
Want the full step-by-step version?
This assumes balanced 120° phase spacing and linear loads — significant harmonic content (especially triplen harmonics from non-linear loads) can cause neutral current to exceed what this formula predicts; see the Harmonic Analysis calculator for that case.