What happens to the AC ESS SHED bus when both engine generators are powering the system?

The AC ESS SHED bus is designed to provide essential electrical power to critical aircraft systems during specific operational scenarios. When both engine generators are online and supplying power, the AC ESS SHED bus is automatically energized. This is crucial for maintaining essential functions and ensuring the aircraft operates effectively during flight.

In normal operations, engine generators are the primary source of electrical power, and they take precedence over other power sources, including the APU. When both engines are running, the system prioritizes stabilizing power distribution, guaranteeing that essential services receive uninterrupted power.

Automatic energization of the AC ESS SHED bus under these circumstances is a fail-safe measure to ensure that vital systems remain operational without requiring pilot intervention. This design reflects the aircraft's focus on reliability and safety, ensuring that power is readily available when needed to support critical functions in flight.