5 Amp Wire Size at 150 Feet (208V Three-Phase (US Commercial Wye))
Complete conductor sizing, Ohm's law voltage drop, $I^2R$ line power loss, and circuit breaker specification for a 5 A load over a 150 ft (45.7 m) one-way run.
Copper Wire (≤3% Drop)14 AWG2.08 mm² · Drop: 1.96%
Aluminum Wire (≤3% Drop)12 AWGDrop: 4.22V (2.03%)
Voltage at Load End203.9 VLoss: 4.07 V (35.3 W)
Power & Breaker (125%)1.8 kW10A Breaker Recommended
All AWG & kcmil Wire Gauges for 5 Amps at 150 Feet (208V)
| Wire Gauge | Metric Area | NEC 75°C Cu Ampacity | Copper Voltage Drop | Load Voltage | Aluminum Drop | Line Loss ($I^2R$) | NEC Status |
|---|---|---|---|---|---|---|---|
| 14 AWG | 2.08 mm² | 15 A | 4.07 V (1.96%) | 203.9 V | 6.72 V (3.23%) | 35.3 W | ✓ PASS (≤3%) |
| 12 AWG | 3.31 mm² | 20 A | 2.56 V (1.23%) | 205.4 V | 4.22 V (2.03%) | 22.2 W | ✓ PASS (≤3%) |
| 10 AWG | 5.26 mm² | 30 A | 1.61 V (0.77%) | 206.4 V | 2.66 V (1.28%) | 14.0 W | ✓ PASS (≤3%) |
| 8 AWG | 8.37 mm² | 50 A | 1.01 V (0.49%) | 207.0 V | 1.67 V (0.8%) | 8.8 W | ✓ PASS (≤3%) |
| 6 AWG | 13.3 mm² | 65 A | 0.64 V (0.31%) | 207.4 V | 1.05 V (0.51%) | 5.5 W | ✓ PASS (≤3%) |
| 4 AWG | 21.15 mm² | 85 A | 0.4 V (0.19%) | 207.6 V | 0.66 V (0.32%) | 3.5 W | ✓ PASS (≤3%) |
| 3 AWG | 26.67 mm² | 100 A | 0.32 V (0.15%) | 207.7 V | 0.52 V (0.25%) | 2.8 W | ✓ PASS (≤3%) |
| 2 AWG | 33.62 mm² | 115 A | 0.25 V (0.12%) | 207.7 V | 0.42 V (0.2%) | 2.2 W | ✓ PASS (≤3%) |
| 1 AWG | 42.41 mm² | 130 A | 0.2 V (0.1%) | 207.8 V | 0.33 V (0.16%) | 1.7 W | ✓ PASS (≤3%) |
| 1/0 AWG | 53.49 mm² | 150 A | 0.16 V (0.08%) | 207.8 V | 0.26 V (0.13%) | 1.4 W | ✓ PASS (≤3%) |
| 2/0 AWG | 67.43 mm² | 175 A | 0.13 V (0.06%) | 207.9 V | 0.21 V (0.1%) | 1.1 W | ✓ PASS (≤3%) |
| 3/0 AWG | 85.01 mm² | 200 A | 0.1 V (0.05%) | 207.9 V | 0.16 V (0.08%) | 0.9 W | ✓ PASS (≤3%) |
| 4/0 AWG | 107.2 mm² | 230 A | 0.08 V (0.04%) | 207.9 V | 0.13 V (0.06%) | 0.7 W | ✓ PASS (≤3%) |
| 250 kcmil | 126.7 mm² | 255 A | 0.07 V (0.03%) | 207.9 V | 0.11 V (0.05%) | 0.6 W | ✓ PASS (≤3%) |
| 300 kcmil | 152.0 mm² | 285 A | 0.06 V (0.03%) | 207.9 V | 0.09 V (0.04%) | 0.5 W | ✓ PASS (≤3%) |
| 350 kcmil | 177.3 mm² | 310 A | 0.05 V (0.02%) | 208.0 V | 0.08 V (0.04%) | 0.4 W | ✓ PASS (≤3%) |
| 400 kcmil | 202.7 mm² | 335 A | 0.04 V (0.02%) | 208.0 V | 0.07 V (0.03%) | 0.4 W | ✓ PASS (≤3%) |
| 500 kcmil | 253.4 mm² | 380 A | 0.03 V (0.02%) | 208.0 V | 0.06 V (0.03%) | 0.3 W | ✓ PASS (≤3%) |
| 600 kcmil | 304.0 mm² | 420 A | 0.03 V (0.01%) | 208.0 V | 0.05 V (0.02%) | 0.2 W | ✓ PASS (≤3%) |
| 750 kcmil | 380.0 mm² | 475 A | 0.02 V (0.01%) | 208.0 V | 0.04 V (0.02%) | 0.2 W | ✓ PASS (≤3%) |
| 1000 kcmil | 506.7 mm² | 545 A | 0.02 V (0.01%) | 208.0 V | 0.03 V (0.01%) | 0.1 W | ✓ PASS (≤3%) |
Frequently Asked Engineering Questions
What size copper wire do I need for 5 amps at 150 feet (208V)?
To stay within the NEC recommended 3% maximum voltage drop for a 5A load over 150 feet one-way at 208V (3-Phase), you need 14 AWG copper wire. This produces a voltage drop of 4.07V (1.96%) and delivers 203.9V at the load.
What size aluminum wire is required for 5 amps at 150 feet?
Using aluminum conductors (75°C rating), you should use 12 AWG to maintain voltage drop at 4.22V (2.03%).
What breaker size is needed for a 5A continuous load?
Under NEC 210.20(A), continuous loads require a circuit breaker rated at 125% of the continuous current (5A × 1.25 = 6.2A), which corresponds to a standard 10A circuit breaker.
Compare Other Distances & Amperages
5 Amp Wire Size by Distance (208V)
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