AC Voltage Drop Calculator

⚡ AC Voltage Drop Calculator

Professional electrical calculations with spreadsheet integration

Circuit ID Current (A) Distance (ft) Wire Size (AWG) Conductor Type Conduit Type Phase Type System Voltage (V) Power Factor Base AC R (Ω/1000ft) Base AC X (Ω/1000ft) Voltage Drop (V) Voltage Drop (%) Actions
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⚠️ Data Source Notice

The wire resistance and reactance values in this calculator are based on older NEC editions and should be verified against the current NEC 2026 Chapter 9, Table 9 for professional use.

Always consult the latest NEC handbook and verify calculations with licensed electrical professionals for critical applications.

🔧 Conduit Material Effects

PVC (Non-metallic): No magnetic effects - base impedance values

EMT (Electrical Metallic Tubing): Thin-wall steel - moderate magnetic effects (+8% R, +12% X)

IMC (Intermediate Metal Conduit): Medium-wall steel - increased magnetic effects (+12% R, +18% X)

RMC (Rigid Metal Conduit): Heavy-wall steel - maximum magnetic effects (+15% R, +25% X)

Steel (Magnetic): General steel conduit - high magnetic coupling (+15% R, +25% X)

Aluminum (Non-magnetic): Eddy current effects only - moderate increase (+5% R, +8% X)

Note: Metallic conduits increase impedance due to magnetic coupling (steel) or eddy currents (aluminum). Effects are more pronounced at higher frequencies and currents.

📐 Calculation Formula

AC Voltage Drop = Phase Multiplier × I × L × (R_eff × cos(φ) + X_eff × sin(φ)) / 1000

Where:

• Phase Multiplier = 2 for Single/Two Phase, √3 for Three Phase

• I = Current in amperes

• L = One-way length in feet

• R_eff = Base AC resistance × Conduit R multiplier (NEC Chapter 9, Table 9)

• X_eff = Base AC reactance × Conduit X multiplier (NEC Chapter 9, Table 9)

• cos(φ) = Power factor

• sin(φ) = √(1 - cos²(φ))

Voltage Drop % = (Voltage Drop / System Voltage) × 100

Phase Types: Single Phase (L-N), Two Phase (L-L), Three Phase (L-L)

Conduit Effects: Metallic conduits increase impedance due to magnetic coupling and eddy currents. Steel conduits have the highest effect, aluminum moderate, and PVC none.

FAQs

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  • It all begins with an idea. Maybe you want to launch a business. Maybe you want to turn a hobby into something more. Or maybe you have a creative project to share with the world. Whatever it is, the way you tell your story online can make all the difference.

  • It all begins with an idea. Maybe you want to launch a business. Maybe you want to turn a hobby into something more. Or maybe you have a creative project to share with the world. Whatever it is, the way you tell your story online can make all the difference.

  • It all begins with an idea. Maybe you want to launch a business. Maybe you want to turn a hobby into something more. Or maybe you have a creative project to share with the world. Whatever it is, the way you tell your story online can make all the difference.