What is the largest circuit breaker size that can be installed on a 12 AWG copper circuit conductor?

The largest circuit breaker size that can be installed on a 12 AWG copper circuit conductor is indeed 20 amps. This is based on the National Electrical Code (NEC), which specifies that for conductors with a specific gauge, there are maximum ratings that should not be exceeded to ensure safety and prevent overheating.

For 12 AWG copper conductors, the code permits a maximum of 20 amps. Exceeding this amperage when connecting a circuit breaker can pose a significant safety hazard, as the conductor may not be able to handle the additional current without risks of overheating, potentially leading to fire or equipment failure.

Understanding these limits helps ensure the proper selection of circuit breakers for the safety and reliability of electrical installations. Therefore, using a 20 amp breaker is not only code-compliant but also essential for maintaining safety standards in electrical work.