What is the resistance of 2,000 feet of AWG #6 copper wire? What is the resistan

Question

What is the resistance of 2,000 feet of AWG #6 copper wire? What is the resistance of 2,000 feet of AWG #6 aluminum wire? Determine the minimum required copper wire size to power a 28VDC motor that uses 40 Amps and is 25 feet from the bus bar (nearest power source). Assume that the power wire is a single wire in free air and that the motor current load is continuous. Is there sufficient information to determine the size of aluminum wire that is required for the circuit in problem 3? (Yes or No) What is the maximum allowable voltage drop for the circuit in problem #3? Electrical resistivities rhoR (= rho0) and temperature coefficients of resistance alpha e for selected conductors Source: Adapted from Handbook of Materials Science, Vol I. Copyright CRC Press. Boca Raton, FL The Science and Design of Engineering Materials, McGraw

Explanation / Answer

From table you will find that the cross sectional area of AWG #6 is 13.3 mm square = 13.3 * 10^-2 cm square

now R = (rho) length/ area

so for copper, rho = 1.67 * 10^-6 and length = 2000 feet = 60960 cm

then R = 1.67 * 10^-6 * 60960 / (13.3 * 10^-2) = 0.765 ohm

2. The area and length remains constant

the rho changes. now rho = 2.65 * 10^-6

so R = 2.65 * 10^-6 * 60960 / (13.3 * 10^-2) = 1.215 ohm

3.Voltage = current * resistance

now voltage = 28 V and current = 40 A

so Resistance = 28/40 = 0.7 ohm

now length of wire is 25 feet = 762 cm

We have to choose the area

R = rho . l / a

so a = rho . l / R = 1.67 * 10^-6 * 762 / (13.3 * 10^-2) = 0.0096 cm square = 0.956 mm square which is roughly the #18 AWG wire

4. Yes, calculate it the same way as done for by simply replacing rho.

5. The maximum allowable volate drop is until the voltage drops to 28 V.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.