In the event of a dual generator failure both the Non-essential and Shed Buses are disconnected from the electrical system. Which of these buses can be reconnected to electrical power from the battery using an overhead switch?

• A. Shed bus
• B. Essential Bus
• C. Main bus 1
• D. Nonessential bus

Answer: (A)

When power from the generators is lost, aircraft electrical systems are designed so that only certain buses can be fed directly from the battery through a dedicated switch. The shed bus is the one configured to receive battery power via the overhead switch, enabling a controlled emergency re-energizing of that path even with generators offline. This design keeps essential loads limited and prevents backfeeding into parts of the system that aren’t rated for direct battery feed.

So, the shed bus can be reconnected to electrical power from the battery using the overhead switch. The non-essential bus isn’t designed to be battery-fed through that switch in this scenario, which is why it isn’t the correct choice.