Kiểm tra & Khắc phục sự cốCâu 496 / 521
A receptacle reads 120 V hot-to-neutral but 0 V hot-to-ground. Neutral-to-ground also reads 0 V and the ground pin has no continuity to the panel. What is the fault?
a.Open equipment grounding conductor (open ground)
b.Reversed polarity
c.Open neutral
d.A bolted line-to-line short
Giải thích
With hot-to-neutral normal at 120 V but hot-to-ground reading 0 V and no continuity from the ground pin back to the panel, the equipment grounding conductor is open. Reversed polarity (b) would still show voltage relationships swapped, an open neutral (c) would kill the hot-to-neutral reading, and a line-to-line short (d) would trip the breaker.
Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- The 2023 NEC added a requirement on how terminations must be tightened when the manufacturer provides a torque value. What does it require?
- A terminal on a device is marked 'CU' only. What does this mean for terminations?
- A newly connected three-phase motor runs backward. What is the standard corrective action?
- Testing a suspected conductor with an ohmmeter, you read 'OL' (over-limit / infinite). What does this indicate about the conductor?
- In a properly bonded system, what is the primary purpose of the equipment grounding conductor during a line-to-enclosure (ground) fault?
- Before touching conductors you believe are de-energized, what is the safest way to verify your voltage tester is trustworthy?
Cập nhật gần nhất: · quy trình kiểm tra
Đội Ngũ Biên Tập PrepPass · Đối chiếu với California CSLB C-10 Electrical Trade Examination · Quy trình kiểm tra