Course Home Page Voltage Drop Test 7 Course Name: Voltage Drop Quiz Number: No. 7 Teacher: Gerald Newton Teacher's Email: electrician@electrician2.com Student Name: Student Email: No. of Questions= 10 Pass mark is - 70 %. To submit this test, press the Submit button at the bottom of the page after Cumulative elapse timer reaches 2,400 seconds. 1. Balancing the load for a three phase, four wire solidly grounded wye system can ________ the voltage drop. a) reduce b) remove c) increase 2. Given 3-ph, 3 wire wye 480 volt system, one way circuit length is 800 feet, load is 76 amperes, conductors are XHHW-2 uncoated copper, operating temperature is 75 degrees C. Power Factor is 1.0. Load is balanced. Find the size of conductor to limit voltage drop to 2 percent. Use K equations with K = 12.9 ohms per circualr mil ohms per ft. a) AWG No. 4 b) 3/0 c) 2/0 d) 1/0 3. Given: Load is 90 amperes. Power Factor is 1.0. 3 each AWG No. 2 XHHW-2 Aluminum conductors Conductors operate at a temperature of 75 C Use approximate K=21.2 circular mil ohms / ft. This is a 480 volt 3 phase, 3 wire system. Find the maximum length for this circuit to maintain a voltage drop of 3 percent. a) 423 feet b) 301 feet c) 289 feet 4. Q factor is equal tot he AC resistance value from Table 9 divided by the DC resistance value from Table ____ in Chapter 9 of the NEC. a) 8 b) 10 c) 9 5. For a Three phase four wire wye system even if the load is balanced, if the load is electric discharge lighting the neutral is ___________ conductor. a) not a current carrying b) redundant c) a current carrying 6. For segmented voltage drop to find the available voltage for each segment we add the voltage drops for each segment and ________ them from the supply voltage to that segment. a) subtract b) add 7. In the diagram the circular mil area required to keep the voltage for for VD1 + VD3 below 8.31 volts is _______ . a) 3500 b) 4999 c) 6530 8. In the diagram the calculated voltage drop for VD1 + VD2 is ________ . a) 6.3 volts b) 8.31 volts c) 4.7 volts 9. Total circuit voltage drop is a sum of the voltage drops of each serial circuit segment for a recreational park feeder, where the load for each segment is calculated using the load that segment sees and the ___________ of 551.73(A). a) demand factors b) 125 percent of the demand factors c) load factors 10. For recreational park feeders and services the demand is _________ for each 50 ampere recreational vehicle site by Section 551.73 (A). a) 2400 volt amperes b) 3600 volt amperes c) 9600 volt amperes Final Elapsed Time at submittal: Go to top of quiz © Gerald Newton
Course Name: Voltage Drop Quiz Number: No. 7 Teacher: Gerald Newton Teacher's Email: electrician@electrician2.com
Student Name: Student Email:
No. of Questions= 10 Pass mark is - 70 %. To submit this test, press the Submit button at the bottom of the page after Cumulative elapse timer reaches 2,400 seconds.