What does the GEN RESET NORM switch allow?

The GEN RESET NORM switch plays a critical role in the operation of the generator control unit (GCU) within an aircraft's electrical system. When the switch is positioned in the reset normal position, it allows the GCU to take over and manage the operations of the generators. This means the GCU can monitor and control the various aspects of generator performance and ensure that they are functioning correctly.

If the switch did not allow the GCU to control generator operations, it could lead to improper system management, which might compromise the reliability of power delivery to critical aircraft systems. This option aligns with the purpose of ensuring that the GCU is actively engaged in regulating the generators, thereby maintaining electrical stability and performance during flight operations.

The other choices do not accurately describe the function of the GEN RESET NORM switch. For instance, isolating the backup power source, activating maintenance mode, or resetting all electrical systems do not directly relate to the primary role of enabling GCU control for generator operations.