Kiểm tra & Khắc phục sự cốCâu 498 / 521
In a properly bonded system, what is the primary purpose of the equipment grounding conductor during a line-to-enclosure (ground) fault?
a.To carry normal load current back to the source
b.To provide a low-impedance fault-current path that lets the overcurrent device trip quickly
c.To improve power factor
d.To limit voltage drop on long runs
Giải thích
The EGC's job on a fault is to give fault current a low-impedance path back to the source so enough current flows to open the breaker/fuse fast, clearing the fault and de-energizing the enclosure. It does not carry normal load current (that's the neutral, a), and it has nothing to do with power factor (c) or normal-load voltage drop (d).
Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- A newly connected three-phase motor runs backward. What is the standard corrective action?
- 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?
- Testing a suspected conductor with an ohmmeter, you read 'OL' (over-limit / infinite). What does this indicate about the conductor?
- Before touching conductors you believe are de-energized, what is the safest way to verify your voltage tester is trustworthy?
- For routine voltage checks at 120 V cord-and-plug receptacle outlets on a branch circuit, what CAT rating is generally the minimum appropriate category?
- You want to measure current with a DMM's internal ammeter function. Which practice is essential to avoid a dangerous fault?
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