Conductors and Cables Flashcards
6 cards from real TN LLE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Conductors and Cables flashcards as text
Per NEC 310.15(B)(7), what ampacity method applies to 120/240V, single-phase dwelling service conductors?
Answer: A special table with higher ampacities for service entrance conductors
NEC 310.15(B)(7) provides a special table with higher ampacities specifically for dwelling unit service and feeder conductors because of the diversity of residential loads.
What is the minimum size copper grounding electrode conductor for a 200-ampere service per NEC Table 250.66?
Answer: 4 AWG
Per NEC Table 250.66, a 200A service with copper service-entrance conductors of 2/0 AWG requires a minimum 4 AWG copper grounding electrode conductor.
When pulling conductors through a conduit, what is the maximum recommended pulling tension for copper conductors to avoid damage?
Answer: 0.008 x cmil per conductor
The industry standard maximum pulling tension for copper conductors is 0.008 pounds per circular mil of conductor area.
Per NEC 300.17, what percentage of a conduit's internal cross-sectional area can be filled when installing 3 or more conductors?
Answer: 40%
NEC Chapter 9, Table 1 limits conduit fill to 40% of the cross-sectional area when 3 or more conductors are installed.
What conductor type is required for wet locations per NEC 310.10(C)?
Answer: Any conductor rated for wet locations such as THWN, XHHW, or USE
NEC 310.10(C) requires conductors in wet locations to be moisture-resistant types listed for the purpose, such as THWN, THWN-2, XHHW, or USE.
Per NEC 240.4(D), what is the maximum overcurrent protection permitted for 14 AWG copper conductors?
Answer: 15 amperes
NEC 240.4(D) limits overcurrent protection for 14 AWG copper to 15 amperes maximum.