While inspecting the copper commutator bars...

Question 1 / 270705eccefa3bacbc34ba4d480a4

Question 1 of 270705eccefa3bacbc34ba4d480a4

While inspecting the copper commutator bars of a DC generator, you notice a chocolate brown film covering the bars. What should be done?

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Question 1 of 27070

While inspecting the copper commutator bars of a DC generator, you notice a chocolate brown film covering the bars. What should be done?

🔍 Key Concepts

• Normal commutator film on copper bars and what it indicates about brush seating and operation • Effects of abrasive materials like emery, sandpaper, and emery cloth on commutator surfaces and brushes • Good maintenance practice for a properly operating DC generator commutator

💭 Think About

• Does a smooth, even chocolate-brown film usually indicate a problem, or proper operation? • What happens if you introduce abrasive grit into the commutator and brush contact area over time? • In standard marine electrical maintenance practice, when is it appropriate to clean/stone a commutator and when is it better not to touch it?

✅ Before You Answer

• Verify what a uniform chocolate-brown film on copper commutator bars usually signifies in DC machines textbooks and manufacturer guidance. • Check which materials (emery, sandpaper, emery cloth) can leave conductive or hard abrasive particles embedded in copper or brushes. • Confirm standard guidance on whether a healthy commutator surface should be aggressively cleaned or left alone.

Question 1 of 27070

While inspecting the copper commutator bars of a DC generator, you notice a chocolate brown film covering the bars. What should be done?

The film should be left undisturbed.

The film should be removed with fine emery cloth.

The film should be removed with fine sandpaper.

The film should be removed with emery paper.

Question 1 / 270705eccefa3bacbc34ba4d480a4

Question 1 of 270705eccefa3bacbc34ba4d480a4

While inspecting the copper commutator bars of a DC generator, you notice a chocolate brown film covering the bars. What should be done?

Back

Question 1 of 27070

While inspecting the copper commutator bars of a DC generator, you notice a chocolate brown film covering the bars. What should be done?