4 AWG Wire: Ampacity, Uses & Specs | PES Supply
4 AWG Wire — Ampacity, Uses & Specifications
4 AWG copper wire is rated for 70-85 amps. Used for 60A sub-panel feeds, large EV chargers, commercial equipment, and generator connections.
4 AWG Wire Specifications
| Specification | Value |
|---|---|
| AWG Size | 4 |
| Ampacity (60°C / 140°F) | 70A |
| Ampacity (75°C / 167°F) | 85A |
| Resistance (Ω/1000 ft, Copper) | 0.249 |
| Wire Types Available | THHN, THWN-2, XHHW-2, USE-2, PV Wire, NM-B (Romex), MC Cable |
| Typical Breaker Size | 70A (60°C) or 85A (75°C) |
Common Applications
4 AWG copper wire is rated for 70-85 amps. Used for 60A sub-panel feeds, large EV chargers, commercial equipment, and generator connections.
Voltage Drop Reference (4 AWG Copper, 240V)
| Distance (ft) | VD @ 85A | % Drop | Status |
|---|---|---|---|
| 25 ft | 1.06V | 0.4% | Good |
| 50 ft | 2.12V | 0.9% | Good |
| 100 ft | 4.23V | 1.8% | Good |
| 150 ft | 6.35V | 2.6% | Good |
| 200 ft | 8.47V | 3.5% | Upsize |
Compatible Breakers and Outlets
For 4 AWG wire at 75°C rating (85A), use a 85A double-pole breaker (240V circuits) or 70A 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