Apprentice roughed in an EV charger circuit: 6-2 NM-B from a 60A breaker, 45 feet through the attic, into a hardwired EVSE set to 48A.

NEC 625.47(A) requires EV charging circuits to have no other loads and be dedicated. Your 6-2 NM-B setup fails multiple code requirements:

1. Ampacity (NEC 310.15(B)(16)): 6 AWG copper is rated 65A at 75°C, but NM-B is 90°C rated. However, 625.47(C) requires conductors to be sized for 125% of the continuous load. A 48A EVSE = 48 × 1.25 = 60A minimum. 6 AWG NM-B is only rated 55A at 60°C (NM-B's termination rating per 110.14(C)(1)(a)), which is undersized.

1. Breaker Compatibility (NEC 240.4(D)): 6 AWG copper requires a 60A breaker max for NM-B (due to 110.14(C) 60°C limitation). A 60A breaker on 55A wire is a code violation.

1. Hardwired EVSE (NEC 625.47(B)): Requires individual conductors in conduit or 6-2 NM-B with equipment grounding conductor (EGC). Your 6-2 NM-B lacks an EGC, which is mandatory for hardwired installations.

Fix: Replace with 6/3 NM-B (adding EGC) or run 6 AWG x 3 conductors in conduit with a 60A breaker. Alternatively, use 4 AWG NM-B (65A at 60°C) with a 60A breaker if the EVSE allows.

Safety Note: This requires a licensed electrician. The undersized wire and missing EGC create fire and shock hazards.

The inspector is correct. 6/2 NM-B is not rated for 60A. You have a fundamental ampacity mismatch.

The Code Violation (NEC 310.16 / 334.80):

• 60°C Column (NM-B limit per 334.80): 6 AWG Copper = 55 Amps.
• 75°C Column (Breaker terminal limit per 110.14(C)): 6 AWG Copper = 65 Amps.
• Rule: You must use the lower of the two: 55 Amps max.

The Circuit Design Failure (NEC 210.19(A)(1), 625.41, 215.2(A)(1)(b)):

1. Continuous Load: EV charging is a continuous load (3+ hours). Conductors and OCPD must be sized at 125% of load.
2. Load Calculation: 48A (EVSE setting) × 1.25 = 60A minimum circuit ampacity required.
3. OCPD Sizing: Breaker must be ≥ 60A (next standard size 625.42). A 60A breaker requires 60A conductor ampacity.
4. The Conflict: Your wire maxes out at 55A. You cannot legally protect it with a 60A breaker (240.4(D) does not apply to #6; 240.4(B) "next size up" only applies if ampacity does not correspond to a standard breaker—55A does not, but 60A breaker exceeds the 55A conductor rating, violating 240.4(D) logic for small conductors and 110.14(C) thermal limits).

The Fix: You need 4/2 NM-B (or 4/3 if neutral required).

• 4 AWG NM-B (60°C Column) = 70 Amps.
• Supports the 60A breaker and 48A continuous load legally.
• Check voltage drop: 45ft @ 48A on #4 Cu ≈ 1.8% (Well within 3% branch circuit recommendation).

Action: Pull the 6/2. Install 4/2 NM-B. Keep the 60A breaker. Re-inspect.