The maximum size of a 3-pole breaker permitted in a panel is rated at what amperage?

The maximum size of a 3-pole breaker in a panel being rated at 80 amperes is based on the National Electrical Code (NEC) guidelines, specifically regarding the utilization of breakers in certain circumstances. In various applications, particularly when calculating feeder or branch circuit demands, it is common to apply a demand factor that might allow you to select a rated breaker size that is lower than the ampacity of the conductors being used.

For a 3-pole breaker, it is crucial to consider the specific ratings and applications, especially in three-phase systems. 80 amperes is a standard maximum for these breakers due to safety considerations and the balancing of loads on each phase of the electrical system. This ensures that the breaker can adequately protect the circuit and handle the load without tripping under normal conditions.

In industrial and commercial settings, adhering to these ratings helps prevent overheating and potential hazards, while providing appropriate protection for the equipment connected to the panel. As such, the established maximum for 3-pole breakers at 80 amperes reflects these safety and operational standards.