3/0 Wire Ampacity & Specifications
NEC ampacity, resistance and typical uses for 3/0 copper and aluminum wire.
Calculations are built on the 2023 National Electrical Code (NEC) and cross-checked against the published code tables. How we verify. Last reviewed June 2026.
Copper 75°C
200A
Copper 90°C
225A
Aluminum 75°C
155A
Typical breaker
200A
3/0 Wire Specifications
| Ampacity — Copper (60 / 75 / 90°C) | 165 / 200 / 225 A |
| Ampacity — Aluminum (60 / 75 / 90°C) | 130 / 155 / 175 A |
| Cross-section | 167,800 circular mils |
| DC resistance — Copper | 0.0766 Ω / 1000 ft |
| DC resistance — Aluminum | 0.126 Ω / 1000 ft |
| Typical voltage drop (240V) | 0.6% at 50 ft · 1.3% at 100 ft (at 200A) |
Common Uses for 3/0 Wire
- 165–200A services and feeders
- 200A copper services (general)
Ampacities are from NEC Table 310.16. 14, 12 and 10 AWG are limited to 15A, 20A and 30A overcurrent protection (240.4(D)). Terminations rated 60°C or 75°C usually cap the usable ampacity below the 90°C value.
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