What are the two most common conductor terminal temperature ratings for circuit breakers rated 100 amperes or less?

The two most common conductor terminal temperature ratings for circuit breakers rated 100 amperes or less are 60°C and 75°C. These ratings are significant because they dictate the maximum allowable temperature that conductors can achieve during operation without compromising safety and performance.

The 60°C rating is typically associated with conductors like those made from certain types of copper or aluminum wire, where a more conservative temperature limit enhances safety and reduces risks of overheating. The 75°C rating often applies to conductors with enhanced insulation properties that can safely carry more current at higher temperatures, providing improved performance in applications that require it.

Understanding these temperature ratings is crucial for ensuring proper wire sizing, installation, and overall safety in electrical systems. When selecting conductors for use with circuit breakers, always refer to the appropriate temperature ratings to ensure compliance with the National Electrical Code (NEC) and to avoid potential hazards such as overheating or electrical fires.