week 4 (chapter 9)

Question 1

distribution lines are typically not longer than ____ miles?

Answer 1

50

Question 2

compared to transmission, distribution is different because the?

Answer 2

direct delivery of power is more localized

Question 3

shorter poles, closer together, more equip, about 300 feet apart?

Answer 3

distribution line

Question 4

special applications for distribution DC power is used for ?

Answer 4

elevators and high rise buildings

Question 5

distribution starts at the _____ and goes to the ______

Answer 5

substation/ customers

Question 6

main lines on a distribution system are also called _____?

Answer 6

feeder lines

Question 7

main lines have larger conductors than ____ lines?

Answer 7

tap

Question 8

four wire, (three phases and a neutral) describes what circuit type?

Answer 8

WYE or star

Question 9

primary is the _____ side, secondary is the ______ side, services run to the __________

Answer 9

high voltage, low voltage, consumer

Question 10

underground systems that are designed so each transformer can be served from two directions are called?

Answer 10

loop feed design

Question 11

number of customers on a circuit is determined by?

Answer 11

area density
type of customer
circuit capacity

Question 12

utilities are obligated to provide voltages at the meter in an acceptable range so ?

Answer 12

customer equip will run efficiently and not be damaged

Question 13

underground lines are about ____ times more expensive than overhead per mile

Answer 13

4

Question 14

most distribution poles are wood, and range from ____ - ____ feet tall

Answer 14

35-55

Question 15

why have distribution conductor sizes increased over the years?

Answer 15

need for more power and reduced line losses

Question 16

the ultimate destination of all power lines is to a ?

Answer 16

transformer or transformer bank

Question 17

protective equipment is designed to ?

Answer 17

distinguish temporary from permanent faults

Question 18

fused cutout switches, re-closures, sectionalizers, and lightning arresters are all what?

Answer 18

protection equipment

Question 19

what is the only way to tell the difference between an ungrounded WYE system and a delta?

Answer 19

back at the substation

Question 20

three phases and a neutral describes what TYPE of circuit?

Answer 20

WYE

Question 21

what type of 3 wire circuit would have no neutral with a transformer hooked up phase to phase?

Answer 21

Delta

Question 22

what side of distribution is lower voltage (120-240), and runs from pole to pole on overhead or underground from pad-mount transformer to pedestal?

Answer 22

secondary

Question 23

the lines that run from pole to customer or from pedestal to customer are?

Answer 23

services

Question 24

underground systems that are designed so that the transformer can be served from two directions are called?

Answer 24

loop design

Question 25

the number of customers on the circuit is determined by the ?

Answer 25

density of area
type of customer
capacity of the circuit

Question 26

7200/12470 is what kind of voltage?

Answer 26

distribution

Question 27

utilities provide power at the meter in a acceptable range so customer equip will?

Answer 27

run efficiently and not get damaged

Question 28

underground systems main disadvantage is that they are?

Answer 28

expensive

Question 29

underground systems are about ____ times more costly than overhead

Answer 29

4

Question 30

what is the most popular choice for poles?

Answer 30

wood

Question 31

what is used to mount equip like transformers, cutouts, riser terminations, lightning arrestors, and insulators?

Answer 31

support brackets and crossarms

Question 32

offer more contact area at the point of attachment and used with large conductors?

Answer 32

post insulator

Question 33

______ insulators are found commonly at dead end structures?

Answer 33

polymer

Question 34

conductor sizes for distibution lines have increased over the years as the result of ?

Answer 34

the need for larger amounts of power and reduced line losses

Question 35

tap lines can be smaller because?

Answer 35

they serve a limited number of customers

Question 36

installed to protect equip such as transformers, and protect the main line from faults that happen on the tap line

Answer 36

fused cut-out switches

Question 37

how many times does a recloser have the ability to reclose after a fault is detected?

Answer 37

4

Question 38

________ are installed to clear faulted sections from the line, and they are coordinated with ?

Answer 38

sectionalizers/reclosers

Question 39

_______ ______ are used to control the voltage out on the line and adjust it plus or minus ____%

Answer 39

voltage regulators/10%

Question 40

capacitors are used to improve the _____ of a circuit?

Answer 40

efficiency

Question 41

_________ reduce inductive load put on the line by transformers and large motors by introducing ?

Answer 41

capacitors/capacitive reactance

Question 42

what does a gang operated switch do?

Answer 42

opens all three phases at the same time

Question 43

underground equipment is commonly classified as either?

Answer 43

pad-mount or subsurface.

Question 44

used to house heavy cables and equipment

Answer 44

Manholes

Question 45

above ground/used to splice low voltage secondary to services

Answer 45

pedestal

Question 46

what is the difference between a dead front and a live front pad mount transformer?

Answer 46

the live front has exposed primary voltage/dead front is all sealed

Question 47

when the circuits are independent of each other leaving the substation and radiate to the service area it is called?

Answer 47

radial

Question 48

when circuits can be connected manually or automatically at one ore more points, this is called?

Answer 48

radial tie

Question 49

when the circuits are connected together, and the step down transformers are connected together to make a low voltage network, it is called?

Answer 49

network grid design