Question 395Electricity & Electronics - Assistant Engineer

The correct answer is B. When the ship's service generator on line fails, the emergency diesel-generator will automatically start and automatically supply power to the 450 VAC section of the emergency bus through the automatic bus transfer device. This is because the emergency diesel-generator is designed to provide backup power to the emergency electrical system, which includes the emergency bus, in the event of a failure of the primary power source. The other options are incorrect because: A) the emergency diesel-generator does not supply power to the main bus, but rather to the emergency bus; C) the automatic bus transfer device does not need to be manually shifted to 'Emergency Power' as it is designed to do this automatically; and D) the emergency diesel-generator does not need to be manually started, as it will automatically start in the event of a failure of the ship's service generator.