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Voltage Drop Calculator

Calculate voltage drop for AC and DC circuits

Input Parameters

How It Works

Voltage drop formulas vary by circuit type:

  • Single Phase / DC: Vd = 2 × I × R × L / 1000
  • Three Phase: Vd = √3 × I × R × L / 1000
  • Percentage Drop: (Vd / System Voltage) × 100%

Recommended maximum voltage drop: 3% for branch circuits, 5% total (feeder + branch).