Final answer:
Pushing the GEN 1 LINE pb to OFF disconnects generator 1 from the aircraft's electrical bus, potentially triggering the system to switch to an alternative power source if available, or to conserve energy by shedding non-essential loads to maintain supply to critical systems.
Step-by-step explanation:
When you push the GEN 1 LINE pb to OFF position in an aircraft, you are intentionally deactivating the generator 1 line contactor, meaning you are disconnecting generator 1 from the electrical bus. In the cockpit of an airplane, specifically for airplanes such as the Airbus A320 family, the GEN 1 LINE pushbutton (pb) is part of the electrical system controls on the overhead panel. If the generator is the primary source of power for the respective bus, and you deactivate it, the system will typically attempt to replace the lost power by automatically connecting to an alternate power source, such as the APU generator, GEN 2, or an external power source if available. This is to maintain a continuous supply of power to the critical systems of the aircraft. However, if no alternative source is available, shedding of non-essential loads may be initiated to conserve power. Pushing the GEN 1 LINE pb to OFF will also trigger caution alerts for the pilots to indicate the change in electrical power configuration.