An toànCâu 423 / 521
A Class A GFCI intended to protect people trips at approximately what ground-fault current?
a.About 20 milliamperes
b.About 100 milliamperes
c.About 5 milliamperes (in the 4-6 mA range)
d.About 1 ampere
Giải thích
A Class A GFCI for personnel protection trips when ground-fault current reaches roughly 4 to 6 mA, low enough to protect against dangerous shock. 20 mA, 100 mA, and 1 A are all far above the let-go and ventricular-fibrillation thresholds and would allow a lethal shock.
Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
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