Course Home Page

Voltage Drop Test 3

Course Name:  Voltage Drop
Quiz Number:  No. 3
Teacher:  Gerald Newton
Teacher's Email:  electrician@electrician2.com

No. of Questions= 10


1.  To find Voltage Drop using Table 9 for AWG size No. 18 to size No. 2 the following equation can be used.
a) VD = ( I x (Rdc/1000) x L ) x M (multiplier)
b) Rdc <= (VDmax E) / (0.1 x L x I x M )
c) L <= (VDmax E) / (0.1x M x Rdc x I)
2.  But for sizes larger than AWG No. 2 on Alternating Current Circuits __________ becomes a factor even when power factor is 1.0 such as we see for resistive type loads.
a) copper loading
b) skin effect
c) inductive reactance
3.  For these smaller wire sizes there are ____________ between Rdc, Rac and Impedance Z.
a) no differences
b) major differences
c) relative minor differences
4.  For conductors larger than No. 2 AWG there are _____________ between Rdc, Rac and Impedance Z.
a) significant differences
b) no differences
c) only small differences
5.  For alternating current and wire sizes larger than AWG No. 2 installed in ___________________as found in Table 9 we can use Rac values from Table 9 to find voltage drop.
a) PVC Conduit
b) Steel Conduit
c) Aluminum Conduit
d) a, b, or c
6.  The AC resistance for 500 kcmil uncoated copper wire installed in steel conduit is _________ ohms to neutral per 1000 feet.
a) 0.095
b) 0.029
c) 0.027
7.  The AC resistance for 400 kcmil uncoated copper wire installed in PVC conduit is _________ ohms to neutral per 1000 feet.
a) 0.038
b) 0.108
c) 0.033
8.  The AC resistance for 300 kcmil Aluminum wire installed in PVC conduit is _________ ohms to neutral per 1000 feet.
a) 0.071
b) 0.045
c) 0.076
9.  Find phase to phase voltage drop for 3 each 350 kcmil XHHW-2 uncoated copper conductors in steel Conduit. Conductors operate at Temperature of 75 C. Use Table 9. Load = 300 amperes; Power Factor = 1.0; One way circuit length is 200 feet. System is 3 phase, 3 wire, 480 volts.
a) 2.0 volts
b) 3.9 volts
c) 4.1 volts
10.  Find the Minimum Conductor Size for conductors to limit voltage drop to 5 percent for the following configuration: 3 each XHHW-2 uncoated copper in steel conduit. Conductors operate at Temperature of 75 C; Load = 90 amperes, Power Factor = 1.0; One way circuit Length is 60 feet. This is a 3 phase 3 wire circuit operating at 480 volts. Be sure and check Table 310.15(B)(16) to make sure the conductors are sized to carry the load of 90 amperes. Remember sizing conductors involves solving two problems: Voltage Drop and Sizing to carry the load so the temperature rating is not exceeded.
a) AWG No. 10
b) AWG No. 3
c) AWG No. 2



Go to top of quiz
© Gerald Newton