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14 AWG Voltage Drop at 240V

This page provides detailed voltage drop analysis for 14 AWG conductors operating at 240V (single-phase). The 14 AWG copper conductor has a resistance of 3.14 ohms per 1000 feet and an ampacity of 20 amps at 75 degrees C per NEC Table 310.16. Use the tables below to determine the voltage drop at any distance and amperage combination, or to find the maximum distance you can run 14 AWG wire while staying within the NEC recommended voltage drop limits.

Wire Gauge
14 AWG
Voltage
240V
Cu Ampacity
20A
Cu Resistance
3.14 Ω/kft

Maximum Distance for 14 AWG at 240V

The table below shows the maximum one-way distance you can run 14 AWG copper conductor at 240V for each amperage level while maintaining voltage drop at or below 3% (branch circuit) and 5% (feeder + branch combined). If your planned run exceeds these distances, you must use a larger wire gauge. These values assume single-phase power with a 2 multiplier in the voltage drop formula.

Amperage Max Distance (3%) Max Distance (5%) 3% Drop = 7.2V
5A 229 ft 382 ft 7.2 V
10A 114 ft 191 ft 7.2 V
15A 76 ft 127 ft 7.2 V
20A 57 ft 95 ft 7.2 V
25A (exceeds ampacity) 45 ft 76 ft 7.2 V

Voltage Drop Table — 14 AWG Copper at 240V

Complete voltage drop matrix for 14 AWG copper conductor at 240V. Each cell shows the voltage drop in volts and percentage. Cells in red exceed the 3% NEC recommendation for branch circuits. Cells within the green range are NEC compliant. This table uses the single-phase voltage drop formula with a conductor resistance of 3.14 ohms per 1000 feet.

Distance 5A10A15A20A25A
25 ft 0.8V
0.3%
1.6V
0.7%
2.4V
1.0%
3.1V
1.3%
3.9V
1.6%
50 ft 1.6V
0.7%
3.1V
1.3%
4.7V
2.0%
6.3V
2.6%
7.8V
3.3%
75 ft 2.4V
1.0%
4.7V
2.0%
7.1V
2.9%
9.4V
3.9%
11.8V
4.9%
100 ft 3.1V
1.3%
6.3V
2.6%
9.4V
3.9%
12.6V
5.2%
15.7V
6.5%
125 ft 3.9V
1.6%
7.8V
3.3%
11.8V
4.9%
15.7V
6.5%
19.6V
8.2%
150 ft 4.7V
2.0%
9.4V
3.9%
14.1V
5.9%
18.8V
7.8%
23.6V
9.8%
200 ft 6.3V
2.6%
12.6V
5.2%
18.8V
7.8%
25.1V
10.5%
31.4V
13.1%
250 ft 7.8V
3.3%
15.7V
6.5%
23.6V
9.8%
31.4V
13.1%
39.3V
16.4%
300 ft 9.4V
3.9%
18.8V
7.8%
28.3V
11.8%
37.7V
15.7%
47.1V
19.6%
400 ft 12.6V
5.2%
25.1V
10.5%
37.7V
15.7%
50.2V
20.9%
62.8V
26.2%
500 ft 15.7V
6.5%
31.4V
13.1%
47.1V
19.6%
62.8V
26.2%
78.5V
32.7%

When to Use 14 AWG at 240V

14 AWG wire at 240V is appropriate for circuits where the amperage does not exceed 20 amps (copper, 75 degrees C) and the voltage drop at the planned distance stays within NEC recommendations. At short distances under 50 feet, 14 AWG handles 16-amp loads with comfortable voltage drop margin. As the distance increases, the voltage drop grows proportionally, and at some point a larger gauge becomes necessary.

If 14 AWG does not provide adequate voltage drop performance for your run distance, consider the next larger gauge. Each step up in wire size roughly doubles the maximum distance for the same voltage drop percentage. Alternatively, if the circuit operates at 120 volts and the distance is problematic, consider whether the load can be served by a 240-volt circuit instead, which halves the percentage voltage drop and doubles the effective run distance for the same wire gauge.

For aluminum conductors, 14 AWG has an ampacity of 16 amps at 75 degrees C and a resistance of 5.17 ohms per 1000 feet. The higher resistance means aluminum requires approximately 65% more distance correction compared to copper, often requiring an increase of one or two gauge sizes to match copper's voltage drop performance at the same distance.

Related Wire Sizes at 240V

Compare voltage drop performance across different wire gauges at 240V. Larger gauges have lower resistance and can run longer distances with less voltage drop.

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