Branch Circuits & FeedersCâu 22 / 120
What is the smallest conductor size generally permitted to be installed in parallel?
a.250 kcmil
b.2 AWG
c.4/0 AWG
d.1/0 AWG
Giải thích
Conductors of 1/0 AWG and larger may be run in parallel when the paralleled sets are the same length, material, size and insulation type and terminate in the same manner. Sizes smaller than 1/0, such as 2 AWG, are not permitted to be paralleled except in a few narrow special applications, and 4/0 or 250 kcmil are simply larger than the stated minimum.
Trích dẫn luật: 2023 NEC §310.10(G)Luyện miễn phí toàn bộ 120 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- Arc-fault circuit-interrupter protection is required for 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets in which dwelling unit areas?
- A 277-volt feeder supplies three continuous lighting loads of 12, 15 and 18 amperes. What is the minimum standard feeder overcurrent device rating?
- For that same 45-ampere continuous lighting feeder, what is the minimum copper conductor size at 75 degrees C terminations?
- The rule permitting the next higher standard overcurrent device rating above the conductor ampacity may be applied only where that device rating does not exceed what value?
- A 200-ampere feeder uses THHN copper conductors, but the equipment terminations are rated 75 degrees C. What is the minimum conductor size?
- Using the dwelling service and feeder conductor table, what is the minimum copper conductor size for a 200-ampere single-phase dwelling service?
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