Voltage Drop Calculator Southwire Online

The Southwire Voltage Drop Calculator is an invaluable tool for calculating the decrease in voltage that occurs in an electrical conductor over distance. Accurately calculating voltage drop is crucial for designing electrical systems that operate efficiently and meet safety standards.

Formula of Voltage Drop Calculator Southwire

The formula used by the Southwire calculator is straightforward yet powerful:

Here’s what each symbol represents:

• VD: Voltage drop in volts.
• L: Length of the conductor in feet.
• I: Current flowing through the conductor in amperes.
• R: Resistance of the conductor in ohms per 1000 feet.

Steps to Calculate Voltage Drop

To utilize this formula effectively, follow these steps:

1. Determine the Conductor Length (L): Measure the total distance from the power source to the load.
2. Determine the Current (I): Identify the current that will flow through the conductor.
3. Find the Conductor Resistance (R): Refer to standard tables to find the resistance value for the conductor material.

Pre-Calculated Table for Common Scenarios

Conductor Length (feet)	Current (amperes)	Conductor Size (AWG)	Voltage Drop (volts)
50	10	12	0.6
50	10	10	0.4
100	10	12	1.2
100	10	10	0.8
150	10	12	1.8
150	10	10	1.2
50	20	12	1.2
50	20	10	0.8
100	20	12	2.4
100	20	10	1.6
150	20	12	3.6
150	20	10	2.4

Example of Voltage Drop Calculator Southwire

Scenario: You are installing a 150-foot aluminum conductor that will carry a current of 20 amperes. The resistance of the conductor is given as 0.156 ohms per 1000 feet.

Step-by-Step Calculation:

1. Determine the Conductor Length (L): 150 feet.
2. Determine the Current (I): 20 amperes.
3. Find the Conductor Resistance (R): 0.156 ohms per 1000 feet.

Apply the Formula: VD = (2 * L * I * R) / 1000

VD = (2 * 150 * 20 * 0.156) / 1000

VD = 936 / 1000 = 0.936 volts

Result: The voltage drop across the conductor is approximately 0.936 volts.

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