8 AWG Wire: Ampacity, Uses & Specs | PES Supply
8 AWG Wire — Ampacity, Uses & Specifications
8 AWG copper wire is rated for 40-50 amps. Used for electric ranges, large water heaters, EV chargers (32-40A), and sub-panel feeds.
8 AWG Wire Specifications
| Specification | Value |
|---|---|
| AWG Size | 8 |
| Ampacity (60°C / 140°F) | 40A |
| Ampacity (75°C / 167°F) | 50A |
| Resistance (Ω/1000 ft, Copper) | 0.628 |
| Wire Types Available | THHN, THWN-2, XHHW-2, USE-2, PV Wire, NM-B (Romex), MC Cable |
| Typical Breaker Size | 40A (60°C) or 50A (75°C) |
Common Applications
8 AWG copper wire is rated for 40-50 amps. Used for electric ranges, large water heaters, EV chargers (32-40A), and sub-panel feeds.
Voltage Drop Reference (8 AWG Copper, 240V)
| Distance (ft) | VD @ 50A | % Drop | Status |
|---|---|---|---|
| 25 ft | 1.57V | 0.7% | Good |
| 50 ft | 3.14V | 1.3% | Good |
| 100 ft | 6.28V | 2.6% | Good |
| 150 ft | 9.42V | 3.9% | Upsize |
| 200 ft | 12.56V | 5.2% | Upsize |
Compatible Breakers and Outlets
For 8 AWG wire at 75°C rating (50A), use a 50A double-pole breaker (240V circuits) or 40A single-pole breaker (120V circuits at 60°C rating).
Related Wire Types
- THHN/THWN-2: For conduit runs, rated 90°C dry / 75°C wet
- NM-B (Romex): For indoor residential wiring, rated 60°C
- MC Cable: Metal-clad, for commercial and exposed runs
- USE-2 / PV Wire: For solar and direct burial, rated 90°C
- XHHW-2: For wet/dry locations, rated 90°C