Question 13035 of 731 · Texas Journeyman Electrician Exam
A 240 volt single-phase load of 40 A is located 180 feet from the panel. What is the smallest copper conductor that keeps voltage drop at or below 3 %?
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 13035
- C: 6 AWG
Explanation
Allowed drop is 0.03 x 240 = 7.2 V, so CM = 2 x 12.9 x 40 x 180 / 7.2 = 25,800 circular mils. 8 AWG (16,510) is too small, so 6 AWG (26,240) is required; leaving out the factor 2 wrongly points to 8 AWG.
More questions: Electrical Calculations
- 13036A three-phase 208 volt load of 90 A is 150 feet from the source. Ignoring ampacity, what is the smallest copper conductor that limits voltage drop to 3 %?
- 13037A three-phase 480 volt load of 100 A is 300 feet away. Ignoring ampacity, what is the smallest aluminum conductor that holds voltage drop to 3 %?
- 13038What is the maximum one-way length for a 120 volt circuit of 12 AWG copper (6,530 circular mils) carrying 16 A if voltage drop must not exceed 3 %?
- 13039A 240 volt single-phase circuit of 8 AWG copper (16,510 circular mils) runs 120 feet one way. What is the maximum load current that keeps voltage drop at 3 %?
- 13040A 240 volt single-phase load draws 50 A through 6 AWG copper (26,240 circular mils) that is 200 feet long one way. What voltage is available at the load?
- 13041On a single-phase circuit, the length of the run is doubled and the load current is cut in half, with the same conductor. What happens to the voltage drop?