Wiring Methods & MaterialsPregunta 64 de 120
Four 3/0 AWG THWN conductors, each 0.2679 square inch in area, are pulled into rigid metal conduit. What is the minimum trade size?
a.2 inch
b.1 and 1/2 inch
c.2 and 1/2 inch
d.1 and 1/4 inch
Explicación
Total conductor area is 4 x 0.2679 = 1.0716 square inches, and with more than two conductors only 40 percent of the raceway may be filled. One and one-half inch RMC allows only about 0.81 square inch at 40 percent, which is too little, while 2 inch RMC allows about 1.34 square inches and is adequate. Two and one-half inch is larger than the calculated minimum.
Referencia Legal: 2023 NEC Chapter 9, Table 4Practica las 120 preguntas gratis — sin registro.
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