Question 13044 of 844 · Washington 01 Journey Level Electrician Exam
A three-phase 208 volt circuit of 10 AWG copper (10,380 circular mils) supplies 25 A per phase at 120 feet one way. What is the percent voltage drop?
Exactly one answer is correct.
You got of questions right. Here on the question pages nobody remembers which ones you got wrong. The trainer saves your progress and asks the mistakes again until they stick.
Or free: the 10 questions most people get wrong
Show solution
Correct answer to question 13044
- D: 3.1 %
Explanation
VD = 1.732 x 12.9 x 25 x 120 / 10,380 = 6.46 V, and 6.46 / 208 = 3.1 %. Using the single-phase factor 2 gives 3.6 %, and dividing by 120 V instead of 208 V gives 5.4 %.
More questions: Electrical Calculations
- 13045A 120 volt, 20 A load is 150 feet from the panel. What is the smallest copper conductor that keeps voltage drop at or below 3 %?
- 13046What is the allowable ampacity of 6 AWG THHN copper (90 °C column) with three current-carrying conductors in a raceway at an ambient temperature of 40 °C?
- 13047Six current-carrying 10 AWG THHN copper conductors share one raceway at 30 °C ambient. What is the adjusted ampacity from the 90 °C column?
- 13048Nine current-carrying 12 AWG THHN copper conductors are installed in one conduit at 30 °C ambient. What is the adjusted ampacity of each conductor based on the 90 °C column?
- 13049Eight current-carrying 12 AWG THHN copper conductors run through an area with a 45 °C ambient. What is the allowable ampacity using the 90 °C column?
- 13050What is the ampacity of 4 AWG THWN copper (75 °C insulation) with three current-carrying conductors at an ambient of 45 °C?