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

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Prepare for the PSA Airlines Canadair Regional Jet Systems Exam. Study with comprehensive flashcards and multiple choice questions, each with hints and explanations. Get ready to excel!

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The DC service switch connects the DC SERV BUS to which of the following?

  1. Main Battery

  2. APU Battery direct bus

  3. AC Main Bus

  4. External Power Source

The correct answer is: APU Battery direct bus

The DC service switch is designed to connect the DC SERV BUS to the APU Battery direct bus. This connection allows the aircraft to utilize power from the auxiliary power unit (APU) when it is running, ensuring that necessary systems can remain operational on the ground without relying solely on the aircraft's main batteries or external power sources. Using APU-generated power is particularly useful during engine start procedures or when the aircraft is on the ground, providing flexibility and maintaining system availability. This configuration prevents excessive drain on the main battery while still providing essential services and allowing for the management of electrical loads on the aircraft. In contrast, the other options either do not align with the purpose and functionality of the DC service switch or represent a different operational mode or power source, highlighting the specialized role of the APU within the electrical system of the aircraft.