In self cooled motors the cooling time constant is about ___________ than the heating time constant because cooling conditions are worse at standstill?
Correct answer: A. 2 to 3 times greater
- A. 2 to 3 times greater
- B. 3 to 4 times greater
- C. 4 to 5 times greater
- D. none of the above
Explanation
In a self-cooled motor, the fan or rotating parts provide much less airflow when the motor is stopped, so cooling is slower at standstill. Consequently, the cooling time constant is typically about two to three times the heating time constant.
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