Question

CHAPTER 6 Wiring Methods 153 24. Dimension a must be at least inches. 25. Dimension b must be at least inches (the conduits contain the same conductors). 26. Dimension e must be at least inches. 27. Do you foresee any difficulties in installing the conductors in these raceways? Explain. 28. The minimum size raceway for the following feeder conductors is: a. Three, 250 kcmil conductors with XHHW insulation b. One, 3/0 AWG conductor with XHHW insulation c. One, 4 AWG conductor with XHHW insulation 29. The minimum size raceway for the following branch circuit conductors is: a. Twelve, 6 AWG conductors with THHN insulation b. Nine, 8 AWG conductors with THHN insulation c. Eighteen, 10 AWG conductor with THHN insulation d. One, 10 AWG equipment grounding conductor with THHN insulation 30. The minimum size wireway for the following feeder with parallel conductors is: a. Two sets of three, 250 kcmil conductors with XHHW insulation b. Two, 3/0 AWG conductor with XHHW insulation c. 1, 4 AWG conductor with XHHW insulation d. The conductors terminate on three power distribution blocks. Each one has a dimension of 4 in. wide and 3 in. high.

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Answer 1

Minimum size Raceway for feeder conductors:

28.a. Each conductor size = 0.3970 sq in.

for 3 conductors size = 0.3970 x 3 = 1.191 sq in.

28.b For one conductor size = 0.2679 sq in.