What is the ampacity of a 1/0 TW copper conductor?

The correct ampacity of a 1/0 TW copper conductor is 125 amps under standard conditions as defined by the National Electrical Code (NEC). Ampacity is primarily determined by the wire gauge, insulation type, and installation conditions. For a 1/0 AWG (American Wire Gauge) copper conductor with thermoplastic insulation (TW), the NEC provides specific ampacity ratings that account for factors like temperature ratings and the installation environment.

The ampacity is consistent because it factors in the thermal limits of the insulation material combined with the maximum allowable current to avoid overheating, which can cause damage or create fire hazards. Given that 1/0 TW copper has a rating of 125 amps, this value is crucial for ensuring electrical installations are safe and efficient. Understanding these ratings helps electricians select the appropriate conductor size based on the expected load to maintain performance and safety within electrical systems.