Theory & SafetyCâu 111 / 120
A balanced three-phase load draws 40 amperes at 480 volts with a power factor of 0.85. What is the true power?
a.Approximately 33.3 kilowatts
b.Approximately 28.3 kilowatts
c.Approximately 19.2 kilowatts
d.Approximately 16.3 kilowatts
Giải thích
True power for a three-phase load is P = 1.732 x E x I x PF = 1.732 x 480 x 40 x 0.85, or about 28,270 watts. The 33.3-kilowatt answer omits the power factor and gives apparent power in kVA instead, 19.2 kilowatts leaves out the 1.732 factor, and 16.3 kilowatts omits both.
Luyện miễn phí toàn bộ 120 câu hỏi — không cần đăng ký.
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