With one or two generators online, which statement describes the network connection?

With one or two generators online, which statement describes the network connection?

• A. One electrical network remains energized while the other is isolated
• B. Both electrical networks interconnected through Bus Tie Contactors. Shed buses de-energized
• C. Only essential buses energized
• D. APU powers all buses

Answer: (B)

The key idea is that the airplane’s two electrical networks are designed to be tied together so power can be shared when generators are online. This is done with the Bus Tie Contactor (BTC). When one or two generators are online, the BTC closes and interconnects the left and right electrical networks, allowing power to flow between them and enabling the systems to support each other if one generator is undersupplied or if a load needs to be redistributed. At the same time, nonessential buses can be shed to keep loads within what the available power can safely supply, so only the essential buses stay energized. This arrangement—networks connected through BTC with shedding of nonessential buses—best describes the normal network configuration under those conditions.

The key idea is that the airplane’s two electrical networks are designed to be tied together so power can be shared when generators are online. This is done with the Bus Tie Contactor (BTC). When one or two generators are online, the BTC closes and interconnects the left and right electrical networks, allowing power to flow between them and enabling the systems to support each other if one generator is undersupplied or if a load needs to be redistributed. At the same time, nonessential buses can be shed to keep loads within what the available power can safely supply, so only the essential buses stay energized. This arrangement—networks connected through BTC with shedding of nonessential buses—best describes the normal network configuration under those conditions.