A diesel engine is driving an alternator...

Question 1 of 270705eccefa1bacbc34ba4d47740

A diesel engine is driving an alternator required to run at 1800 RPM. The over speed governor is normally required to be set within a range of __________.

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Question 1 of 27070

A diesel engine is driving an alternator required to run at 1800 RPM. The over speed governor is normally required to be set within a range of __________.

🔍 Key Concepts

• Relationship between rated speed and overspeed setting on diesel engines • Typical percentage range (in % of rated speed) used for overspeed governors on generators/alternators • How to convert a percentage of RPM into an actual RPM range

💭 Think About

• First, think about what percentage above rated speed is normally allowed before an overspeed trip must act on a marine diesel driving a generator. • Calculate 10%, 15%, and 20% of 1800 RPM, then add those values to 1800. Which of the answer choices lines up with the normal overspeed percentage range? • Compare how far above 1800 RPM each choice is. Which one represents a moderate safety margin, not too small and not excessively high?

✅ Before You Answer

• Compute 10% of 1800 RPM and 15% of 1800 RPM, then express those as RPM values added to 1800. • Check which choice falls roughly between 110% and 115% of rated speed (a commonly cited range for overspeed settings on this type of machinery). • Eliminate any ranges that imply the engine would have to reach far above 20% overspeed before the governor acts, as this would usually be unsafe.