What Is the Voltage Drop for 3/0 AWG at 53A and 150 Feet?

3/0 AWG at 53A and 150 feet: 1.22V drop (1.01% on 120V), computed on the single-phase / DC basis. Every conductor has resistance, and longer runs at higher currents drop more voltage. Use this calculation to check whether your run clears the 3% branch-circuit drop target before pulling wire.

3/0 AWG, 53A, 150ft · single-phase / DC
1.22 V drop (1.01% on 120V)
On 120V circuit1.01%
On 240V circuit0.5075%

Circuit basis: This uses the single-phase / DC round-trip formula (factor of 2) for the voltage drop across the two circuit conductors. For a three-phase line-to-line run use the three-phase version of the page (append ?type=3ph). Switch to the three-phase version →

3/0 AWG
1.22V (1.01%)

Assumes a 120V source on a single-phase / DC circuit. Use the circuit-basis link above to switch between single-phase/DC and three-phase.

Voltage Drop Formula (single-phase / DC)

Vdrop = (2 × L × I × R) ÷ 1000

(2 × 150 × 53 × 0.0766) ÷ 1000 = 1.22 V

DC and single-phase AC use the round-trip factor of 2. Current travels out to the load on one conductor and returns on another.

For a three-phase circuit at the same amps and distance, see the three-phase version (uses √3 instead of 2, so the drop is about 13.4% lower).

Percentage

%VD = (Vdrop ÷ Vsource) × 100

On 120V: (1.22 ÷ 120) × 100 = 1.01%
On 240V: (1.22 ÷ 240) × 100 = 0.5075%

How This Estimate Changes with Run Length and Gauge

Gauge Check

3/0 AWG clears the 3% drop target at these inputs. A smaller conductor may also meet it with less margin. See the minimum gauge for this load and distance.

Impact of Distance

Voltage drop is proportional to distance. Here is 3/0 AWG at 53A at different distances:

DistanceDrop (V)% on 120V% on 240VNEC (120V)
25ft0.203V0.1692%0.0846%OK
50ft0.406V0.3383%0.1692%OK
75ft0.609V0.5075%0.2537%OK
100ft0.812V0.6766%0.3383%OK
150ft1.22V1.01%0.5075%OK
200ft1.62V1.35%0.6766%OK
300ft2.44V2.03%1.01%OK

Same Run, Different Wire Gauges

How does wire gauge affect voltage drop for 53A at 150 feet on 120V single-phase / DC? Only gauges whose branch-circuit OCP cap is at or above the 53A load are listed, since thinner gauges would fail the ampacity check before drop even matters.

GaugeDrop (V)% on 120V% on 240V3% Target (120V)
3/0 AWG1.22V1.01%0.5075%OK
4/0 AWG0.9667V0.8056%0.4028%OK
250 kcmil0.8188V0.6824%0.3412%OK
300 kcmil0.6821V0.5684%0.2842%OK
350 kcmil0.5835V0.4863%0.2431%OK
500 kcmil0.4102V0.3419%0.1709%OK

Frequently Asked Questions

3/0 AWG carrying 53A over 150ft has a 1.22V drop (1.01% on 120V). Reference: 0.5075% on 240V.
Motors run hotter and can have trouble starting under load. Incandescent and halogen lighting dims. Some electronics misbehave at the low end of their input tolerance. Energy is wasted as I²R heating in the conductor. These are performance issues; high drop is not itself a code violation unless the specific installation cites a hard limit.
Same wire, same amps, same distance: the volts dropped are identical. But the percentage is worse on 120V because the drop is a larger fraction of the source voltage. This run would be 0.5075% on 240V versus 1.01% on 120V.
On 120V, this run sits at 1.01%, which is within the 3% branch and 5% feeder+branch total drop targets. NEC 210.19(A) Informational Note 4 cites 3% for branch circuits and 5% for total feeder+branch drop as performance recommendations, not hard code requirements.
3/0 AWG already sits within the 3% branch-circuit drop target at these inputs (1.01% on 120V). Going to a larger gauge is only useful if you want more headroom for future load growth, longer runs, or tighter drop targets like the 5% feeder+branch total recommendation used in sensitive or motor-heavy installations.
This calculator provides estimates for reference purposes only. Always consult a licensed electrician and verify compliance with the National Electrical Code (NEC) and local electrical codes before performing any electrical work.