Neutral Current Calculator

Max deviation from the average phase current, as a percentage. Beyond ~10%, the loaded phase overheats its winding share (aging the transformer asymmetrically), the neutral carries real current, and I²R losses rise quadratically. It's the most common, most fixable distribution defect.

Two causes: unbalanced single-phase loads (the vector remainder lands on the neutral — this tool estimates it) and triplen harmonics from electronic loads, which ADD arithmetically in the neutral regardless of balance. If measured neutral exceeds this tool's estimate, harmonics are the difference.

Redistribution: move single-phase consumers/loads between phases at the pillar box or panel until peak-hour readings converge — typically an afternoon's work with a clamp meter, costing nothing. Re-measure at the same hour; balance shifts with the daily load pattern.

Yes — heating follows each winding's own current squared: at 20% unbalance, the heavy phase runs ~44% more I²R heat than balanced operation would give it, and the hot-spot lives in that winding. The transformer's life is its hottest phase's life.