How can the loss of residual magnetism in an...

Question 1 / 270705eccefa3bacbc34ba4d48033

Question 1 of 270705eccefa3bacbc34ba4d48033

How can the loss of residual magnetism in an alternator with a brushless excitation system be corrected?

Question 1 of 27070

How can the loss of residual magnetism in an alternator with a brushless excitation system be corrected?

🔍 Key Concepts

• Residual magnetism and why an alternator needs it to start building voltage • How a brushless excitation system gets DC into the rotating field without slip rings • What "flashing the field" means in generator maintenance

💭 Think About

• Which of these actions actually introduces an external DC source into the field circuit so magnetism can be re‑established? • Do any of the options involving just running the machine (speed or direction) actually add new magnetism if there is none left to begin with? • In normal troubleshooting practice, what do technicians do when a generator will not build up voltage because of lost residual magnetism?

✅ Before You Answer

• Identify which choice directly applies DC from a separate source to the field circuit. • Eliminate options that only change speed or direction but do not provide an external excitation source. • Recall that "flashing the field" is a standard procedure described in generator maintenance manuals for restoring residual magnetism.

Question 1 of 27070

How can the loss of residual magnetism in an alternator with a brushless excitation system be corrected?

using a storage battery or battery charger to "flash" the field

running the rotor in the opposite direction for 5 minutes

running the generator at normal speed with the field rheostat fully counterclockwise

allowing the generator to run at 10% of normal speed for 5 minutes

Question 1 / 270705eccefa3bacbc34ba4d48033

Question 1 of 270705eccefa3bacbc34ba4d48033

How can the loss of residual magnetism in an alternator with a brushless excitation system be corrected?

Back

Question 1 of 27070

How can the loss of residual magnetism in an alternator with a brushless excitation system be corrected?