You are correct. Based on the National Electrical Code (NEC) and general electrical practices, #6 NM cable is not code-compliant for use on a 60-amp breaker. Here's why: Ampacity Ratings

NM (Non-Metallic) cable has ampacity ratings dependent on the temperature rating of the terminations. In most cases, you are limited to the 60°C column of Table 310.16 in the NEC. #6 NM cable is typically rated for a maximum of 55 amps in this column.

Overcurrent Protection

An overcurrent protection device (like a circuit breaker) must be sized to protect the conductor. Using a 60-amp breaker on a cable rated for 55 amps would violate this principle. It would allow the cable to potentially overheat and become a fire hazard before the breaker trips.

Standard Sizes

While you might find some variations, the standard ampacity for a #6 NM cable in residential applications is generally considered to be 55 amps.

To reiterate, the correct combination would be



60A Breaker

Requires conductors rated for at least 60 amps.

Appropriate Wire Size

To meet the 60-amp requirement, you would typically need #4 AWG NM cable (check the appropriate NEC table based on conductor temperature rating for exact requirements).

Important Considerations



Local Codes

Always check with your local electrical codes and permitting authorities. They may have specific amendments or interpretations that differ from the NEC.

Professional Installation

Electrical work can be dangerous. It is best practice to have a qualified and licensed electrician perform the work. They will ensure that the installation is safe and meets all applicable codes.

Conduit vs. NM: If you are already running conduit, consider using THHN/THWN individual conductors inside the conduit. This is often more cost-effective for larger sizes and offers better ampacity in some situations. Flag for review