TN LLE Conductors and Cables 3

Question 1

Per NEC 310.15(B)(7), what ampacity method applies to 120/240V, single-phase dwelling service conductors?

Accepted Answer

A special table with higher ampacities for service entrance conductors

Answer

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.

Question 2

What is the minimum size copper grounding electrode conductor for a 200-ampere service per NEC Table 250.66?

Accepted Answer

4 AWG

Answer

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.

Question 3

When pulling conductors through a conduit, what is the maximum recommended pulling tension for copper conductors to avoid damage?

Accepted Answer

0.008 x cmil per conductor

Answer

The industry standard maximum pulling tension for copper conductors is 0.008 pounds per circular mil of conductor area.

Question 4

Per NEC 300.17, what percentage of a conduit's internal cross-sectional area can be filled when installing 3 or more conductors?

Accepted Answer

40%

Answer

NEC Chapter 9, Table 1 limits conduit fill to 40% of the cross-sectional area when 3 or more conductors are installed.

Question 5

What conductor type is required for wet locations per NEC 310.10(C)?

Accepted Answer

Any conductor rated for wet locations such as THWN, XHHW, or USE

Answer

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.

TN LLE - Tennessee Limited Licensed Electrician Practice Test

TN LLE - Tennessee Limited Licensed Electrician Practice Test

TN LLE Conductors and Cables 3