One thousand circular mils or $1 \mathrm{kcmil}$ is sometimes designated by the abbreviation MCM. Data for commercial bare aluminum electrical conductors lists a $60-\mathrm{Hz}$ resistance of $0.0740 \mathrm{ohm}$ per kilometer at $75^{\circ} \mathrm{C}$ for a 954-MCM AAC conductor. (a) Determine the cross-sectional conducting area of this conductor in square meters. (b) Find the $60-\mathrm{Hz}$ resistance of this conductor in ohms per kilometer at $45^{\circ} \mathrm{C}$.

Question

Quizplus · Accepted Answer

The Answer is (a)

954 \mathrm{MCM}=\left(954 imes 10^{3} \mathrm{cmil} ight)\left(\frac{\frac{\pi}{4} ext { sqmil }}{1 \mathrm{cmil}} ight)\left(\frac{1 \mathrm{in}}{1000 \mathrm{mil}} ight)^{2}\left(\frac{.0254 \mathrm{~m}}{ ext { in }} ight)^{2}

=\underline{\underline{4.834 imes 10^{-4}} \mathrm{~m}^{2}}

(b)

R_{60 \mathrm{~HƵ}, 45^{\circ}}=R_{60 \mathrm{~Hz}, 75^{\circ}}\left(\frac{45+T}{75+T} ight)

\begin{aligned}& =(0.0740)\left(\frac{45+228.1}{75+228.1} ight)=(0.0740)(0.9010) \& =\underline{\underline{0.0667} \Omega / \mathrm{km}}\end{aligned}

One Thousand Circular Mils Or 1kcmil1 \mathrm{kcmil}1kcmil Is Sometimes Designated by the Abbreviation MCM

One Thousand Circular Mils Or $1 \mathrm{kcmil}$ Is Sometimes Designated by the Abbreviation MCM