AC Three-phase Voltage Drop Calculator

How to Calculate Voltage Drop

To calculate the voltage drop, input the current, length, material, AWG, and type of circuit. The calculator will use the appropriate formula to determine the voltage drop.

For AC Single-phase and DC circuits:

$$ V_{drop} = \frac{2 \times I \times \rho \times L}{A} $$

For Three-phase circuits:

$$ V_{drop} = \frac{\sqrt{3} \times I \times \rho \times L}{A} $$

Example Calculation

Let's calculate the voltage drop for a copper wire (AWG 10) with a current of 15 A, a length of 50 meters, and a single-phase AC circuit.

Given:

• Current, \( I = 15 \) A
• Length, \( L = 50 \) m
• Resistivity of copper, \( \rho = 1.68 \times 10^{-8} \) Ω·m
• Cross-sectional area for AWG 10, \( A = 5.261 \) mm² = \( 5.261 \times 10^{-6} \) m²

Using the formula for AC Single-phase:

$$ V_{drop} = \frac{2 \times 15 \times 1.68 \times 10^{-8} \times 50}{5.261 \times 10^{-6}} $$

Calculating the voltage drop:

$$ V_{drop} = \frac{2 \times 15 \times 1.68 \times 10^{-8} \times 50}{5.261 \times 10^{-6}} = 4.9 \text{ V} $$

Definitions

• Current (I): The flow of electric charge, measured in amperes (A).
• Resistivity (ρ): A material property that indicates how much the material resists the flow of electric current, measured in ohm-meters (Ω·m).
• Cross-Sectional Area (A): The area of the wire's cross-section, measured in square meters (m²).
• Voltage Drop (V_drop): The reduction in voltage in an electrical circuit between the source and load.
• Length (L): The length of the wire, measured in meters (m) or feet (ft).

Conversion Table