Which switch allows the isolation of the battery bus and generator bus?

The Bus Tie Switch is integral for managing electrical power distribution within an aircraft system. It allows the isolation of the battery bus from the generator bus, which is crucial for maintaining control and safety during various operational scenarios.

When the Bus Tie Switch is in the open position, it effectively separates these two power sources, ensuring that any potential issues or faults on one bus do not affect the other. This isolation is particularly important during situations like engine failure or electrical malfunctions, as it allows for a focused and safe troubleshooting process.

In contrast, the other switches serve different functions within the electrical system. The Start Switch is primarily tasked with initiating the engine or auxiliary power unit start sequence. The Generator Control Switch is focused on managing the connection and operation of the generators themselves, rather than controlling their relationship with the battery bus. The Power Selector Switch is used to choose the source of power for various systems but does not provide the same level of bus isolation as the Bus Tie Switch. Thus, the Bus Tie Switch is vital for isolating the battery and generator systems, enhancing safety and system reliability.