For a load drawing 27.8 amps in a 120/240-volt three-phase panel, what is its power usage in kVA?

Study for the Independent Electrical Contractors (IEC) Year 2 Part 3 Test. Use flashcards and multiple choice questions with hints and explanations to prepare confidently. Get exam-ready now!

To calculate the power usage in kilovolt-amperes (kVA) for a load drawing 27.8 amps in a 120/240-volt three-phase panel, you can use the formula for three-phase power:

[ \text{kVA} = \frac{\sqrt{3} \times V_{LL} \times I}{1000} ]

Where:

  • ( V_{LL} ) is the line-to-line voltage (in volts),

  • ( I ) is the current (in amps).

In a 120/240-volt three-phase system, the line-to-line voltage is 240 volts. Plugging the values into the formula:

[ \text{kVA} = \frac{\sqrt{3} \times 240 \times 27.8}{1000} ]

Calculating this step-by-step:

  1. Find ( \sqrt{3} ), which is approximately 1.732.

  2. Multiply ( 240 \times 27.8 = 6672 ).

  3. Then, multiply that by ( \sqrt{3} ): ( 1.732 \times 6672 \approx 11549.184 ).

  4. Finally,

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