Voltage Drop Tables

480 volts three-phase is the standard power distribution voltage in industrial and large commercial facilities. The higher voltage reduces conductor size requirements by a factor of 4 compared to 120V for the same power delivery, making it the most efficient choice for large motors, industrial equipment, and long feeder runs. Power is typically distributed at 480V and then stepped down to 120/208V at local transformers for receptacles and lighting.

Understanding Voltage Drop at 480V

Voltage drop is the reduction in voltage between the source (panel) and the load (device) caused by the resistance of the conductors. At 480 volts, a 3% voltage drop equals 14.4 volts, meaning the voltage at the load would be 465.6 volts. The NEC recommends keeping voltage drop below 3% for branch circuits and below 5% for the combined feeder and branch circuit. While these are recommendations rather than mandatory requirements, they represent accepted engineering practice and are enforced by most electrical inspectors.

480V systems require arc flash labeling per NFPA 70E. Equipment and conductors must be rated for the higher voltage. Three-phase voltage drop calculations use the 1.732 factor.

Common 480V circuits include: Large industrial motors (50-500 HP), industrial welding equipment, large HVAC chillers, main distribution feeders, industrial compressors, CNC machines. Each of these applications has specific NEC requirements for wire sizing, overcurrent protection, and installation methods. The tables below provide voltage drop values for copper conductors at various distances and amperages, organized by wire gauge, so you can quickly determine whether a specific gauge is adequate for your installation.

Quick Reference: Maximum Distance by Gauge at 480V

The table below shows the maximum one-way distance for each copper wire gauge at common amperages to maintain a voltage drop of 3% or less at 480 volts (three phase). If your run distance exceeds these values, you must use a larger wire gauge.

Gauge	30A Max Dist	50A Max Dist	100A Max Dist	150A Max Dist	200A Max Dist
10 AWG	223 ft	134 ft	67 ft	44 ft	33 ft
8 AWG	356 ft	213 ft	106 ft	71 ft	53 ft
6 AWG	564 ft	338 ft	169 ft	112 ft	84 ft
4 AWG	899 ft	539 ft	269 ft	179 ft	134 ft
3 AWG	1131 ft	678 ft	339 ft	226 ft	169 ft
2 AWG	1428 ft	857 ft	428 ft	285 ft	214 ft
1 AWG	1799 ft	1079 ft	539 ft	359 ft	269 ft
1/0 AWG	2271 ft	1362 ft	681 ft	454 ft	340 ft
2/0 AWG	2865 ft	1719 ft	859 ft	573 ft	429 ft
3/0 AWG	3617 ft	2170 ft	1085 ft	723 ft	542 ft
4/0 AWG	4558 ft	2734 ft	1367 ft	911 ft	683 ft
250 kcmil	5381 ft	3228 ft	1614 ft	1076 ft	807 ft
300 kcmil	6460 ft	3876 ft	1938 ft	1292 ft	969 ft
350 kcmil	7551 ft	4530 ft	2265 ft	1510 ft	1132 ft
400 kcmil	8633 ft	5180 ft	2590 ft	1726 ft	1295 ft
500 kcmil	10741 ft	6445 ft	3222 ft	2148 ft	1611 ft

14 AWG Voltage Drop at 480V

Voltage drop values for 14 AWG copper conductor (3.14 ohms/kft) at 480 volts, three phase. Ampacity at 75°C: 20A. Cells in red exceed the 3% NEC recommendation.

Distance	30A	50A	100A	150A	200A
25 ft	4.1V 0.8%	6.8V 1.4%	13.6V 2.8%	20.4V 4.3%	27.2V 5.7%
50 ft	8.2V 1.7%	13.6V 2.8%	27.2V 5.7%	40.8V 8.5%	54.4V 11.3%
75 ft	12.2V 2.5%	20.4V 4.3%	40.8V 8.5%	61.2V 12.8%	81.6V 17.0%
100 ft	16.3V 3.4%	27.2V 5.7%	54.4V 11.3%	81.6V 17.0%	108.8V 22.7%
125 ft	20.4V 4.3%	34.0V 7.1%	68.0V 14.2%	102.0V 21.2%	136.0V 28.3%
150 ft	24.5V 5.1%	40.8V 8.5%	81.6V 17.0%	122.4V 25.5%	163.2V 34.0%
200 ft	32.6V 6.8%	54.4V 11.3%	108.8V 22.7%	163.2V 34.0%	217.5V 45.3%
250 ft	40.8V 8.5%	68.0V 14.2%	136.0V 28.3%	203.9V 42.5%	271.9V 56.6%
300 ft	49.0V 10.2%	81.6V 17.0%	163.2V 34.0%	244.7V 51.0%	326.3V 68.0%
400 ft	65.3V 13.6%	108.8V 22.7%	217.5V 45.3%	326.3V 68.0%	435.1V 90.6%
500 ft	81.6V 17.0%	136.0V 28.3%	271.9V 56.6%	407.9V 85.0%	543.9V 113.3%

12 AWG Voltage Drop at 480V

Voltage drop values for 12 AWG copper conductor (1.98 ohms/kft) at 480 volts, three phase. Ampacity at 75°C: 25A. Cells in red exceed the 3% NEC recommendation.

Distance	30A	50A	100A	150A	200A
25 ft	2.6V 0.5%	4.3V 0.9%	8.6V 1.8%	12.9V 2.7%	17.1V 3.6%
50 ft	5.1V 1.1%	8.6V 1.8%	17.1V 3.6%	25.7V 5.4%	34.3V 7.1%
75 ft	7.7V 1.6%	12.9V 2.7%	25.7V 5.4%	38.6V 8.0%	51.4V 10.7%
100 ft	10.3V 2.1%	17.1V 3.6%	34.3V 7.1%	51.4V 10.7%	68.6V 14.3%
125 ft	12.9V 2.7%	21.4V 4.5%	42.9V 8.9%	64.3V 13.4%	85.7V 17.9%
150 ft	15.4V 3.2%	25.7V 5.4%	51.4V 10.7%	77.2V 16.1%	102.9V 21.4%
200 ft	20.6V 4.3%	34.3V 7.1%	68.6V 14.3%	102.9V 21.4%	137.2V 28.6%
250 ft	25.7V 5.4%	42.9V 8.9%	85.7V 17.9%	128.6V 26.8%	171.5V 35.7%
300 ft	30.9V 6.4%	51.4V 10.7%	102.9V 21.4%	154.3V 32.1%	205.8V 42.9%
400 ft	41.1V 8.6%	68.6V 14.3%	137.2V 28.6%	205.8V 42.9%	274.4V 57.2%
500 ft	51.4V 10.7%	85.7V 17.9%	171.5V 35.7%	257.2V 53.6%	342.9V 71.4%

10 AWG Voltage Drop at 480V

Voltage drop values for 10 AWG copper conductor (1.24 ohms/kft) at 480 volts, three phase. Ampacity at 75°C: 35A. Cells in red exceed the 3% NEC recommendation.

Distance	30A	50A	100A	150A	200A
25 ft	1.6V 0.3%	2.7V 0.6%	5.4V 1.1%	8.1V 1.7%	10.7V 2.2%
50 ft	3.2V 0.7%	5.4V 1.1%	10.7V 2.2%	16.1V 3.4%	21.5V 4.5%
75 ft	4.8V 1.0%	8.1V 1.7%	16.1V 3.4%	24.2V 5.0%	32.2V 6.7%
100 ft	6.4V 1.3%	10.7V 2.2%	21.5V 4.5%	32.2V 6.7%	43.0V 8.9%
125 ft	8.1V 1.7%	13.4V 2.8%	26.9V 5.6%	40.3V 8.4%	53.7V 11.2%
150 ft	9.7V 2.0%	16.1V 3.4%	32.2V 6.7%	48.3V 10.1%	64.4V 13.4%
200 ft	12.9V 2.7%	21.5V 4.5%	43.0V 8.9%	64.4V 13.4%	85.9V 17.9%
250 ft	16.1V 3.4%	26.9V 5.6%	53.7V 11.2%	80.5V 16.8%	107.4V 22.4%
300 ft	19.3V 4.0%	32.2V 6.7%	64.4V 13.4%	96.7V 20.1%	128.9V 26.9%
400 ft	25.8V 5.4%	43.0V 8.9%	85.9V 17.9%	128.9V 26.9%	171.8V 35.8%
500 ft	32.2V 6.7%	53.7V 11.2%	107.4V 22.4%	161.1V 33.6%	214.8V 44.7%

8 AWG Voltage Drop at 480V

Voltage drop values for 8 AWG copper conductor (0.778 ohms/kft) at 480 volts, three phase. Ampacity at 75°C: 50A. Cells in red exceed the 3% NEC recommendation.

Distance	30A	50A	100A	150A	200A
25 ft	1.0V 0.2%	1.7V 0.3%	3.4V 0.7%	5.0V 1.1%	6.7V 1.4%
50 ft	2.0V 0.4%	3.4V 0.7%	6.7V 1.4%	10.1V 2.1%	13.5V 2.8%
75 ft	3.0V 0.6%	5.0V 1.1%	10.1V 2.1%	15.2V 3.2%	20.2V 4.2%
100 ft	4.0V 0.8%	6.7V 1.4%	13.5V 2.8%	20.2V 4.2%	26.9V 5.6%
125 ft	5.0V 1.1%	8.4V 1.8%	16.8V 3.5%	25.3V 5.3%	33.7V 7.0%
150 ft	6.1V 1.3%	10.1V 2.1%	20.2V 4.2%	30.3V 6.3%	40.4V 8.4%
200 ft	8.1V 1.7%	13.5V 2.8%	26.9V 5.6%	40.4V 8.4%	53.9V 11.2%
250 ft	10.1V 2.1%	16.8V 3.5%	33.7V 7.0%	50.5V 10.5%	67.4V 14.0%
300 ft	12.1V 2.5%	20.2V 4.2%	40.4V 8.4%	60.6V 12.6%	80.8V 16.8%
400 ft	16.2V 3.4%	26.9V 5.6%	53.9V 11.2%	80.8V 16.8%	107.8V 22.5%
500 ft	20.2V 4.2%	33.7V 7.0%	67.4V 14.0%	101.1V 21.1%	134.8V 28.1%

6 AWG Voltage Drop at 480V

Voltage drop values for 6 AWG copper conductor (0.491 ohms/kft) at 480 volts, three phase. Ampacity at 75°C: 65A. Cells in red exceed the 3% NEC recommendation.

Distance	30A	50A	100A	150A	200A
25 ft	0.6V 0.1%	1.1V 0.2%	2.1V 0.4%	3.2V 0.7%	4.3V 0.9%
50 ft	1.3V 0.3%	2.1V 0.4%	4.3V 0.9%	6.4V 1.3%	8.5V 1.8%
75 ft	1.9V 0.4%	3.2V 0.7%	6.4V 1.3%	9.6V 2.0%	12.8V 2.7%
100 ft	2.5V 0.5%	4.3V 0.9%	8.5V 1.8%	12.8V 2.7%	17.0V 3.5%
125 ft	3.2V 0.7%	5.3V 1.1%	10.6V 2.2%	15.9V 3.3%	21.3V 4.4%
150 ft	3.8V 0.8%	6.4V 1.3%	12.8V 2.7%	19.1V 4.0%	25.5V 5.3%
200 ft	5.1V 1.1%	8.5V 1.8%	17.0V 3.5%	25.5V 5.3%	34.0V 7.1%
250 ft	6.4V 1.3%	10.6V 2.2%	21.3V 4.4%	31.9V 6.6%	42.5V 8.9%
300 ft	7.7V 1.6%	12.8V 2.7%	25.5V 5.3%	38.3V 8.0%	51.0V 10.6%
400 ft	10.2V 2.1%	17.0V 3.5%	34.0V 7.1%	51.0V 10.6%	68.0V 14.2%
500 ft	12.8V 2.7%	21.3V 4.4%	42.5V 8.9%	63.8V 13.3%	85.0V 17.7%

4 AWG Voltage Drop at 480V

Voltage drop values for 4 AWG copper conductor (0.308 ohms/kft) at 480 volts, three phase. Ampacity at 75°C: 85A. Cells in red exceed the 3% NEC recommendation.

Distance	30A	50A	100A	150A	200A
25 ft	0.4V 0.1%	0.7V 0.1%	1.3V 0.3%	2.0V 0.4%	2.7V 0.6%
50 ft	0.8V 0.2%	1.3V 0.3%	2.7V 0.6%	4.0V 0.8%	5.3V 1.1%
75 ft	1.2V 0.3%	2.0V 0.4%	4.0V 0.8%	6.0V 1.3%	8.0V 1.7%
100 ft	1.6V 0.3%	2.7V 0.6%	5.3V 1.1%	8.0V 1.7%	10.7V 2.2%
125 ft	2.0V 0.4%	3.3V 0.7%	6.7V 1.4%	10.0V 2.1%	13.3V 2.8%
150 ft	2.4V 0.5%	4.0V 0.8%	8.0V 1.7%	12.0V 2.5%	16.0V 3.3%
200 ft	3.2V 0.7%	5.3V 1.1%	10.7V 2.2%	16.0V 3.3%	21.3V 4.5%
250 ft	4.0V 0.8%	6.7V 1.4%	13.3V 2.8%	20.0V 4.2%	26.7V 5.6%
300 ft	4.8V 1.0%	8.0V 1.7%	16.0V 3.3%	24.0V 5.0%	32.0V 6.7%
400 ft	6.4V 1.3%	10.7V 2.2%	21.3V 4.5%	32.0V 6.7%	42.7V 8.9%
500 ft	8.0V 1.7%	13.3V 2.8%	26.7V 5.6%	40.0V 8.3%	53.4V 11.1%

3 AWG Voltage Drop at 480V

Voltage drop values for 3 AWG copper conductor (0.245 ohms/kft) at 480 volts, three phase. Ampacity at 75°C: 100A. Cells in red exceed the 3% NEC recommendation.

Distance	30A	50A	100A	150A	200A
25 ft	0.3V 0.1%	0.5V 0.1%	1.1V 0.2%	1.6V 0.3%	2.1V 0.4%
50 ft	0.6V 0.1%	1.1V 0.2%	2.1V 0.4%	3.2V 0.7%	4.2V 0.9%
75 ft	0.9V 0.2%	1.6V 0.3%	3.2V 0.7%	4.8V 1.0%	6.4V 1.3%
100 ft	1.3V 0.3%	2.1V 0.4%	4.2V 0.9%	6.4V 1.3%	8.5V 1.8%
125 ft	1.6V 0.3%	2.6V 0.6%	5.3V 1.1%	8.0V 1.7%	10.6V 2.2%
150 ft	1.9V 0.4%	3.2V 0.7%	6.4V 1.3%	9.6V 2.0%	12.7V 2.6%
200 ft	2.5V 0.5%	4.2V 0.9%	8.5V 1.8%	12.7V 2.6%	17.0V 3.5%
250 ft	3.2V 0.7%	5.3V 1.1%	10.6V 2.2%	15.9V 3.3%	21.2V 4.4%
300 ft	3.8V 0.8%	6.4V 1.3%	12.7V 2.6%	19.1V 4.0%	25.5V 5.3%
400 ft	5.1V 1.1%	8.5V 1.8%	17.0V 3.5%	25.5V 5.3%	34.0V 7.1%
500 ft	6.4V 1.3%	10.6V 2.2%	21.2V 4.4%	31.8V 6.6%	42.4V 8.8%

2 AWG Voltage Drop at 480V

Voltage drop values for 2 AWG copper conductor (0.194 ohms/kft) at 480 volts, three phase. Ampacity at 75°C: 115A. Cells in red exceed the 3% NEC recommendation.

Distance	30A	50A	100A	150A	200A
25 ft	0.3V 0.1%	0.4V 0.1%	0.8V 0.2%	1.3V 0.3%	1.7V 0.3%
50 ft	0.5V 0.1%	0.8V 0.2%	1.7V 0.3%	2.5V 0.5%	3.4V 0.7%
75 ft	0.8V 0.2%	1.3V 0.3%	2.5V 0.5%	3.8V 0.8%	5.0V 1.1%
100 ft	1.0V 0.2%	1.7V 0.3%	3.4V 0.7%	5.0V 1.1%	6.7V 1.4%
125 ft	1.3V 0.3%	2.1V 0.4%	4.2V 0.9%	6.3V 1.3%	8.4V 1.8%
150 ft	1.5V 0.3%	2.5V 0.5%	5.0V 1.1%	7.6V 1.6%	10.1V 2.1%
200 ft	2.0V 0.4%	3.4V 0.7%	6.7V 1.4%	10.1V 2.1%	13.4V 2.8%
250 ft	2.5V 0.5%	4.2V 0.9%	8.4V 1.8%	12.6V 2.6%	16.8V 3.5%
300 ft	3.0V 0.6%	5.0V 1.1%	10.1V 2.1%	15.1V 3.1%	20.2V 4.2%
400 ft	4.0V 0.8%	6.7V 1.4%	13.4V 2.8%	20.2V 4.2%	26.9V 5.6%
500 ft	5.0V 1.1%	8.4V 1.8%	16.8V 3.5%	25.2V 5.3%	33.6V 7.0%

1 AWG Voltage Drop at 480V

Voltage drop values for 1 AWG copper conductor (0.154 ohms/kft) at 480 volts, three phase. Ampacity at 75°C: 130A. Cells in red exceed the 3% NEC recommendation.

Distance	30A	50A	100A	150A	200A
25 ft	0.2V 0.0%	0.3V 0.1%	0.7V 0.1%	1.0V 0.2%	1.3V 0.3%
50 ft	0.4V 0.1%	0.7V 0.1%	1.3V 0.3%	2.0V 0.4%	2.7V 0.6%
75 ft	0.6V 0.1%	1.0V 0.2%	2.0V 0.4%	3.0V 0.6%	4.0V 0.8%
100 ft	0.8V 0.2%	1.3V 0.3%	2.7V 0.6%	4.0V 0.8%	5.3V 1.1%
125 ft	1.0V 0.2%	1.7V 0.3%	3.3V 0.7%	5.0V 1.0%	6.7V 1.4%
150 ft	1.2V 0.3%	2.0V 0.4%	4.0V 0.8%	6.0V 1.3%	8.0V 1.7%
200 ft	1.6V 0.3%	2.7V 0.6%	5.3V 1.1%	8.0V 1.7%	10.7V 2.2%
250 ft	2.0V 0.4%	3.3V 0.7%	6.7V 1.4%	10.0V 2.1%	13.3V 2.8%
300 ft	2.4V 0.5%	4.0V 0.8%	8.0V 1.7%	12.0V 2.5%	16.0V 3.3%
400 ft	3.2V 0.7%	5.3V 1.1%	10.7V 2.2%	16.0V 3.3%	21.3V 4.5%
500 ft	4.0V 0.8%	6.7V 1.4%	13.3V 2.8%	20.0V 4.2%	26.7V 5.6%

1/0 AWG Voltage Drop at 480V

Voltage drop values for 1/0 AWG copper conductor (0.122 ohms/kft) at 480 volts, three phase. Ampacity at 75°C: 150A. Cells in red exceed the 3% NEC recommendation.

Distance	30A	50A	100A	150A	200A
25 ft	0.2V 0.0%	0.3V 0.1%	0.5V 0.1%	0.8V 0.2%	1.1V 0.2%
50 ft	0.3V 0.1%	0.5V 0.1%	1.1V 0.2%	1.6V 0.3%	2.1V 0.4%
75 ft	0.5V 0.1%	0.8V 0.2%	1.6V 0.3%	2.4V 0.5%	3.2V 0.7%
100 ft	0.6V 0.1%	1.1V 0.2%	2.1V 0.4%	3.2V 0.7%	4.2V 0.9%
125 ft	0.8V 0.2%	1.3V 0.3%	2.6V 0.6%	4.0V 0.8%	5.3V 1.1%
150 ft	0.9V 0.2%	1.6V 0.3%	3.2V 0.7%	4.8V 1.0%	6.3V 1.3%
200 ft	1.3V 0.3%	2.1V 0.4%	4.2V 0.9%	6.3V 1.3%	8.4V 1.8%
250 ft	1.6V 0.3%	2.6V 0.6%	5.3V 1.1%	7.9V 1.6%	10.6V 2.2%
300 ft	1.9V 0.4%	3.2V 0.7%	6.3V 1.3%	9.5V 2.0%	12.7V 2.6%
400 ft	2.5V 0.5%	4.2V 0.9%	8.4V 1.8%	12.7V 2.6%	16.9V 3.5%
500 ft	3.2V 0.7%	5.3V 1.1%	10.6V 2.2%	15.8V 3.3%	21.1V 4.4%

Other Voltage Levels

View voltage drop tables for other standard voltages. Higher voltages result in lower percentage voltage drop for the same absolute voltage loss, which allows longer conductor runs without upsizing.

120 Volt

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