Question 8003 of 749 · Maryland Journeyperson Electrician Exam
When sizing motor branch-circuit conductors and short-circuit protection for a general-purpose motor, which current must be used?
Exactly one answer is correct.
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Correct answer to question 8003
- A: The full-load current from the NEC motor tables
Explanation
Section 430.6(A)(1) requires the table values (Tables 430.247 to 430.250) rather than the nameplate current for conductor ampacity and for short-circuit and ground-fault protection. The table values give a consistent, conservative basis.
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- 8004Which value is used to size separate motor overload protection?
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- 8006A motor is marked with a temperature rise of 40 degrees C. What overload rating is permitted as a percentage of nameplate current?
- 8007A motor has a service factor of 1.0 and no temperature rise marking. What is the maximum overload rating?
- 8008A motor with a service factor of 1.0 has a nameplate current of 20 A. What is the maximum separate overload setting under 430.32(A)(1)?
- 8009The overload selected at 125 percent is not enough to start a motor with a service factor of 1.15. What is the highest rating the next step permits?