WireMath

1/0 AWG voltage drop at 200 feet

Computed voltage drop for 1/0 AWG copper conductors on a 200 ft one-way run.

5.86 V

drop on 1/0 AWG copper, 200 ft one-way, 120 A load · 4.9% of 120 V · 2.4% of 240 V

1/0 AWG at 200 ft by load

LoadDrop% at 120 V% at 240 V3% rule (240 V)
30 A1.46 V1.2%0.6%OK
60 A2.93 V2.4%1.2%OK
90 A4.39 V3.7%1.8%OK
120 A5.86 V4.9%2.4%OK

Vd = 2 × length × R × I ÷ 1000, R = 0.122 Ω/1000 ft (copper, NEC Ch. 9 Table 8). Aluminum is about 1.6× higher.

Same wire, other distances

25 ft · 50 ft · 75 ft · 100 ft · 125 ft · 150 ft · 250 ft · 300 ft

FAQ

What is the voltage drop on 1/0 AWG wire at 200 feet?

At 120 A (80% of its 150 A 75°C rating) 1/0 AWG copper drops 5.86 V over 200 ft one-way: 4.9% at 120 V or 2.4% at 240 V.

How far can I run 1/0 AWG at 120 amps?

To stay within 3% at 120 V, about 123 ft one-way; at 240 V about 246 ft.