Services, Grounding & BondingCâu 39 / 120
A service is supplied by a single set of 500 kcmil copper ungrounded conductors. What is the minimum size copper main bonding jumper?
a.3/0 AWG
b.2 AWG
c.4 AWG
d.1/0 AWG
Giải thích
The main bonding jumper is sized from the same table used for the grounded conductor and supply-side bonding jumpers, and the over 350 through 600 kcmil row calls for 1/0 copper. The 2 AWG and 4 AWG answers come from smaller service conductor rows, and 3/0 applies to much larger services.
Trích dẫn luật: 2023 NEC §250.28(D)(1)Luyện miễn phí toàn bộ 120 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- A 200-ampere feeder requires what minimum size copper equipment grounding conductor?
- What is the minimum size copper equipment grounding conductor for a 400-ampere feeder?
- A 100-ampere feeder originally sized with 3 AWG copper (52,620 circular mils) is upsized to 1/0 AWG copper (105,600 circular mils) for voltage drop. What is the minimum equipment grounding conductor?
- A service uses two parallel sets of 750 kcmil copper per phase. Using the 12.5 percent rule, what is the minimum copper main bonding jumper?
- Service-entrance conductors supply 68 amperes of continuous load plus 120 amperes of noncontinuous load. What minimum ampacity must the conductors have?
- Using the dwelling conductor table, what is the minimum copper conductor size for a 400-ampere single-phase dwelling service?
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