If it becomes absolutely necessary to run an...

Question 1 / 270705eccefa4bacbc34ba4d48176

Question 1 of 270705eccefa4bacbc34ba4d48176

If it becomes absolutely necessary to run an alternator at lower than 5% below its rated frequency, in terms of output voltage, what must be done?

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Question 1 of 27070

If it becomes absolutely necessary to run an alternator at lower than 5% below its rated frequency, in terms of output voltage, what must be done?

🔍 Key Concepts

• Relationship between frequency and voltage in AC generators (alternators) • V/Hz (volts per hertz) ratio and magnetic flux in iron cores • Effects of low frequency on heating and magnetic saturation in connected equipment (motors, transformers)

💭 Think About

• If you lower the frequency but keep the same voltage, what happens to the volts-per-hertz (V/Hz) ratio and the magnetic flux in the alternator and connected equipment? • What is usually done to the terminal voltage when frequency drops, in order to avoid over‑fluxing and overheating of transformers and motors? • Look at the answer choices and ask: which one protects the insulation and iron core from excessive flux when running below rated frequency?

✅ Before You Answer

• Be clear on how V/Hz ratio changes when frequency decreases but voltage stays constant. • Think about which option would reduce the risk of over‑fluxing and overheating at lower frequency. • Eliminate any choice that would increase stress on the alternator and connected equipment when the frequency is already too low.

Question 1 of 27070

If it becomes absolutely necessary to run an alternator at lower than 5% below its rated frequency, in terms of output voltage, what must be done?

The alternator output voltage must be maintained at the rated value for the alternator output voltage.

The alternator output voltage must be increased proportionately upward to compensate for the frequency decrease.

The alternator output voltage must be decreased proportionately downward with the frequency decrease.

Under no circumstances is it permissible to run an alternator at a frequency lower than 5% below its rated frequency.

Question 1 / 270705eccefa4bacbc34ba4d48176

Question 1 of 270705eccefa4bacbc34ba4d48176

If it becomes absolutely necessary to run an alternator at lower than 5% below its rated frequency, in terms of output voltage, what must be done?

Back

Question 1 of 27070

If it becomes absolutely necessary to run an alternator at lower than 5% below its rated frequency, in terms of output voltage, what must be done?