When a 240-volt motor operates and the conductor connected to L1 contacts the metal enclosure, what causes the 2-pole circuit breaker to trip?

The key concept involved in this scenario is the principle of electrical grounding and circuit protection. When a 240-volt motor operates, it typically uses two live conductors (L1 and L2) for power. If the conductor connected to L1 makes contact with the metal enclosure of the motor, it creates a fault condition where current is diverted from the intended circuit path.

In this case, the fault allows current to flow through the metal enclosure to the ground, which creates an excess current condition. The 2-pole circuit breaker is designed to detect such imbalances in current. The breaker measures the difference in current between the two live wires. If there is a fault, this difference will trigger the breaker to trip, cutting off current to protect both the motor and the electrical circuit.

The option chosen reflects the proper sequence of events and parameters that lead to the trip of the circuit breaker due to the direct fault and grounding involved in this situation. It's crucial that circuit breakers respond to ground faults, as this behavior enhances safety by preventing electrical shock hazards and potential fire risks.