What type of current flow does a circuit breaker interrupt in a 3-phase system?

A circuit breaker in a 3-phase system is designed to interrupt both alternating current (AC) and direct current (DC) flow. The primary function of a circuit breaker is to protect electrical circuits from overloads and faults by breaking the circuit when a fault condition occurs.

In a 3-phase system, while AC is the most common type of current used, there are applications where DC is also utilized, particularly in specific industrial and commercial settings. Therefore, the ability to interrupt both AC and DC current is essential for the circuit breaker's versatility and effectiveness in ensuring safety and preventing potential damage to electrical equipment and hazards due to electrical faults.

This capability is particularly relevant in modern electrical systems that might incorporate both types of current across various applications. Hence, recognizing that a circuit breaker can handle interruptions of both AC and DC current helps in understanding its comprehensive role in protecting a circuit in a 3-phase system.