Which of the following methods is NOT a valid approach for reducing arc energy in circuit breakers?

Increasing the instantaneous trip setting does not effectively reduce arc energy in circuit breakers. The instantaneous trip setting determines the threshold at which the circuit breaker will trip in response to a fault condition. By increasing this setting, you essentially raise the level of fault current required to initiate a trip, which can result in a longer duration of arcing before the breaker disconnects the circuit.

The objective of reducing arc energy is to minimize the energy release during an arc flash incident, thereby reducing the potential for injury and equipment damage. Other methods, such as energy-reducing active arc flash mitigation systems and energy-reducing maintenance switching, are specifically designed to detect and reduce the impact of arcing events by reacting quickly and lowering the energy during such occurrences. Differential relaying also works to provide faster fault detection by comparing the currents entering and leaving a section of the circuit, which helps in timely tripping to reduce arc energy.

Thus, increasing the instantaneous trip setting contradicts the goal of reducing arc energy, making it the option that does not align with effective arc flash mitigation strategies.