Minimum size by temperature column
| Conductor | 60°C | 75°C | 90°C |
|---|---|---|---|
| Copper | 4 AWG70 A | 6 AWG65 A | 6 AWG75 A |
| Aluminum | 3 AWG65 A | 4 AWG65 A | 4 AWG75 A |
Equipment grounding conductor
A circuit protected at 60 A takes a 10 AWG copper or 8 AWG aluminum equipment grounding conductor, from the 60 A row of NEC Table 250.122. Raise the ground with the ungrounded conductors when you increase them for voltage drop or any reason other than 310.15(B) or (C) derating, because 250.122(B) requires the same proportion. The ground is never required to be larger than the circuit conductors.
Longest run at 3% voltage drop
| Conductor | 120 V | 240 V |
|---|---|---|
| 4 AWG copper | 95 ft | 190 ft |
| 3 AWG aluminum | 70 ft | 145 ft |
NEC 210.19(A)(1) Informational Note 4 recommends keeping branch-circuit drop at or below 3%. These lengths come from the Table 8 resistance at 75°C for a stranded conductor at unity power factor, rounded to the nearest 5 ft. Reactance is not included, so a large conductor in a steel raceway falls short of the figure. A three-phase run reaches about 15% farther than these single-phase figures.
What a 60 A circuit feeds
- Shop and outbuilding subpanel feeders
- Dual-oven ranges and 48 A EV charging
Sixty amps is a feeder rating and the largest charging circuit a house usually has. It takes 4 AWG copper or 3 AWG aluminum at 60°C. In conduit with 75°C terminations, 6 AWG copper carries 65 A and is one size smaller than the 60°C answer, which is what most electricians pull for this rating.
A 60 A circuit is usually a feeder rather than a branch circuit, so it ends at a panel or a disconnect instead of a receptacle. Standard 60 A receptacles exist in the 14-60 configuration but are rare in homes, which is why equipment at this rating is hardwired. Small commercial buildings use the same rating for three-phase feeders, where the conductor ampacities are unchanged.
A feeder is sized from the calculated load, not from the bus rating of the panel it supplies, so a 60 A feeder can feed a 100 A panel when the calculation supports it. That is common in shops and outbuildings. The 125% rule for continuous loads applies to the loads the feeder carries, so a feeder serving only receptacles is calculated differently from one serving a charger.
60 A wire size questions
- What size wire do I need for a 60 amp circuit?
- Use 4 AWG copper or 3 AWG aluminum at the 60°C column, which sets the default under 110.14(C)(1)(a) for equipment rated 100 A or less, and 334.80 and 340.80 hold NM-B and UF-B cable to that column regardless of the terminals. With 75°C terminations, 6 AWG copper or 4 AWG aluminum carries the circuit.
- What size ground wire for a 60 amp circuit?
- 10 AWG copper or 8 AWG aluminum, taken from the 60 A row of NEC Table 250.122.
- What size aluminum wire for 60 amps?
- 3 AWG aluminum at the 60°C column carries 65 A. Terminations on aluminum conductors must be identified for the material.
- Can I use 6 AWG copper for 60 A?
- Table 310.16 lists 6 AWG copper at 55 A at 60°C, 65 A at 75°C, and 75 A at 90°C. It falls short at 60°C, the column this circuit uses. The 75°C and 90°C columns do reach 60 A, and a higher column applies only where every termination is listed for it.
- Is 60 A enough for EV charging?
- A 48 A EV charger is the largest continuous load a 60 A circuit can supply, because 625.41 requires a branch circuit rated at 125% of the charger's maximum load. At that size the charger is hardwired rather than plugged in.