A current density of __________ is ilsed for large power transformers with forced circulation of oil or with water cooling coils?
Correct answer: D. 5.4 to 6.2 A/mm2
- A. 1.5 to 2.5 A/mm2
- B. 3.5 to 4.5 A/mm2
- C. 4.0 to 5.0 A/mm2
- D. 5.4 to 6.2 A/mm2
Explanation
Forced oil circulation or water-cooled coils remove heat more effectively, allowing a higher winding current density than ordinary natural cooling. The commonly used range for such large transformers is about 5.4 to 6.2 A/mm².
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