PSA Airlines Canadair Regional Jet Systems (PSA-CRJ) Practice Exam

What is the power priority for AC BUS 2?

1. Gen1, Gen2, APU Gen, Ext PWR

2. Onside, APU, Offside, Exterior

3. APU, GEN1, GEN2, Ext PWR

4. Gen2, APU Gen, GEN1, Ext PWR

The correct answer is: Gen2, APU Gen, GEN1, Ext PWR

The power priority for AC BUS 2 indicates the order in which power sources are utilized when supplying electricity to the bus within the aircraft's electrical system. The correct answer reflects the established sequence of power sources that provide electricity to AC BUS 2. In this case, the priority begins with Gen2 as the first source of power, followed by APU Generator, then GEN1, and finally, External Power. This order is important to understand, as it ensures that the most reliable and available power source is used first, which helps maintain electrical system stability and functionality. Having Gen2 at the top of the priority list signifies that the system prioritizes on-board generated power from the left engine, followed by the auxiliary power unit (APU) and then switching to GEN1 if required. External power is the last resort, indicating that it is used only when all other options are not available. This hierarchy is critical for safe operations, especially during phases of flight where engine power might not be available.