Theory & SafetyCâu 120 / 120
Which sequence correctly describes verifying that equipment is de-energized before beginning work?
a.Test the meter on a known live source, test the de-energized conductors, then retest the meter on the known live source
b.Test the de-energized conductors, then test the meter on a known live source
c.Rely on the open position of the disconnect and the applied lock
d.Test the de-energized conductors only, since the meter was checked at the start of the shift
Giải thích
The live-dead-live method proves the instrument is working both before and after the absence-of-voltage test, so a meter that failed during the check cannot lead a worker to treat energized conductors as safe. Locking and tagging the disconnect is required, but it does not by itself confirm that the conductors ahead of the work are actually de-energized, since backfeeds and mislabeled circuits are common.
Luyện miễn phí toàn bộ 120 câu hỏi — không cần đăng ký.
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