Question 13019 of 844 · Washington 01 Journey Level Electrician Exam
A 3-phase 4-wire wye feeder has linear loads of 50 A on phase A, 40 A on phase B and 30 A on phase C. What is the approximate neutral current?
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 13019
- C: 17.3 A
Explanation
For a wye system, IN = square root of (A squared + B squared + C squared minus AB minus BC minus CA) = square root of (2,500 + 1,600 + 900 minus 2,000 minus 1,200 minus 1,500) = square root of 300 = 17.3 A. Subtracting the smallest from the largest (20 A) is the single-phase shortcut that does not apply here.
More questions: Electrical Calculations
- 13020What is the line-to-neutral voltage of a 480Y/277 volt system, calculated from the 480 volt line-to-line value?
- 13021Each winding of a balanced delta-connected load carries 20 amperes. What is the line current?
- 13022What is the apparent power of a three-phase 480 volt load drawing 100 amperes per line?
- 13023A plant load of 100 kW operates at 0.80 power factor. About how much capacitor kVAR is needed to raise the power factor to 0.95?
- 13024Resistors of 6, 3 and 2 ohms are connected in parallel. What is the total resistance?
- 13025A 10 ohm and a 15 ohm resistor are connected in parallel. What is the equivalent resistance?