Calculate voltage drop in electrical wires and cables. Essential tool for electricians, engineers, and electrical contractors to ensure proper wire sizing and electrical system performance.
The voltage drop calculator is an essential tool for electrical professionals and enthusiasts. It calculates the voltage drop that occurs in electrical conductors due to their resistance. Understanding voltage drop is crucial for proper electrical system design and ensuring equipment operates efficiently and safely.
Voltage drop occurs when electrical current flows through a conductor, causing a reduction in voltage from the source to the load. Excessive voltage drop can cause equipment malfunction, reduced efficiency, and potential safety hazards. The National Electrical Code (NEC) recommends that voltage drop should not exceed 3% for branch circuits and 5% for feeders.
This calculator considers various factors including wire gauge, material (copper or aluminum), length, current, temperature, and conductor configuration to provide accurate voltage drop calculations.
Enter System Voltage: Input the nominal voltage of your electrical system (e.g., 120V, 240V, 480V).
Enter Current: Input the expected current load in amperes that will flow through the conductor.
Enter Length: Input the one-way length of the conductor run in feet (from source to load).
Select Wire Type: Choose between copper or aluminum conductors (copper has lower resistance).
Select Wire Gauge: Click on the appropriate AWG (American Wire Gauge) size for your conductor.
Configure Options: Select the number of conductors and operating temperature.
Calculate: Click "Calculate Voltage Drop" to get your results including voltage drop, percentage drop, and recommendations.
| AWG Size | Copper Resistance (Ω/1000ft) | Aluminum Resistance (Ω/1000ft) | Max Current (A) |
|---|---|---|---|
| 14 | 2.525 | 4.148 | 15 |
| 12 | 1.588 | 2.609 | 20 |
| 10 | 0.999 | 1.643 | 30 |
| 8 | 0.628 | 1.034 | 40 |
| 6 | 0.395 | 0.651 | 55 |
| 4 | 0.249 | 0.410 | 70 |
| 2 | 0.156 | 0.257 | 95 |
| 1 | 0.124 | 0.204 | 110 |
NEC Guidelines: The National Electrical Code recommends voltage drop should not exceed 3% for branch circuits and 5% for feeders.
Temperature Effects: Higher temperatures increase conductor resistance, resulting in higher voltage drop.
Wire Sizing: If voltage drop is excessive, consider using larger wire gauge or shorter runs.
Safety: Always consult with a qualified electrician for electrical installations and modifications.