High Voltage Quizzes

Question 1

Fuses are LESS likely to be found in transmission systems then in distribution sytems. T/F

Answer 1

True

Question 2

Purpose of the insulation shioelding is to equalize stresses in insulation> T/F

Answer 2

True

Question 3

Which CB is suitable for different high voltage ranges?

Answer 3

Inert gas/SF6

Question 4

Air magnetic CB characterisitics?

Answer 4

-arc runners
-arc contacts
-puffer
-arc chute/arc splitter

Question 5

Air blast CB characteristics?

Answer 5

-air receiver
-exhaust valve
-looks complicated
-has air tank i believe

Question 6

Ground mat overcomes problems of touch and step voltage. T/F

Answer 6

True

Question 7

Class tour TX operates at 7.2KV. T/F

Answer 7

True

Question 8

Big device in switchyard with 3 big cone looking horns coming off?

Answer 8

Shunt reactor

Question 9

Benefits of using HV for electricity distribution?

Answer 9

-reduces material weight
-decreases power losses
-reduces line current

Question 10

Consequence of only grounding one end of the shield?

Answer 10

High voltage at the ungrounded end during a fault

Question 11

Conductor shield overcomes the problem of ionized air between the conductor strands and insulation. T/F

Answer 11

True

Question 12

Grounded System % insulation?

Answer 12

100%

Question 13

Ungrounded system % insulation?

Answer 13

133%

Question 14

Class 1 termination characteristics?

Answer 14

-stress relief
-anti tracking
-seal to the environment

Question 15

Class 2 termination characteristics?

Answer 15

-stress relief
-anti tracking

Question 16

Class 3 termination characteristics?

Answer 16

-stress relief

Question 17

Differential relays used to protect generators, large motors, transformers and even feeder cable. T/F

Answer 17

True

Question 18

Using skirting termination in clean, dry, indoor environment advantage?

Answer 18

shorter distance is required withing the switch gear

Question 19

Least likely to encounter this type of fuse nowadays?

Answer 19

Liquid type

Question 20

Whaat type of CB is normally required to be installed in a vault?

Answer 20

Oil

Question 21

Marking on TX what does each one mean: 1985, 72x144, 50, OLTC?

Answer 21

1985 is year installed. 7.2 is primary voltage, 50is the kva, and OLTC is on load tap changer.

Question 22

2 factors that influence magnitude of voltage on transmission lines?

Answer 22

load and distance

Question 23

3 most common methods of siolating HV equipment from the general public?

Answer 23

Elevation, Vault, substation

Question 25

Conductor shield creates equidistant radial flux within the insulation of HV cable. T/F

Answer 25

False, isnualtion shield creates this

Question 26

Testing a cable with DC hipot linear relation with the stepped aplied voltge and leakage current, howevver further increase in stepped voltage cause the leakage current to have a sharp rise, what happened?

Answer 26

insulation is starting to break down

Question 27

Insulated rubber gloves tested how often after being issued for service?

Answer 27

Every 6 months

Question 28

HV switch on pole top in horizontal position, typically able to interrupt magnetizing current of 15A, what type of switch is it?

Answer 28

Horn gap switch

Question 29

Voltage regualtion?

Answer 29

change of average voltage across the load from the no load theoretical value expressed as percentage of no load voltage

Question 30

HV fuse that has replaceable fuse link?

Answer 30

Distribution cut out

Question 31

Purpose of lead sheath on cable?

Answer 31

keep moisture out and provide insulation shielding

Question 32

HV fuse that has the fastest reaction ina fault situation?

Answer 32

Current limiting

Question 33

Which fuse may produce xrays under certain conditions?

Answer 33

Vacuum

Question 34

BIL rating of lighnting arrestors must be higher then the equipment they protect. T/F

Answer 34

True

Question 35

Most common form of insulation on HV cables?

Answer 35

Plastic

Question 36

HV CB used only on trasmission voltage levels is?

Answer 36

Air blast

Question 37

Lightning rods are connected tp the ground to protect the building? T/F

Answer 37

True

Question 38

Insulation shield in HV cable must be grounded. T/F

Answer 38

True

Question 39

of electric flux lines emanting from HV conductor depends on?

Answer 39

voltage on the conductors

Question 40

Materials contained within a current limiting fuse?

Answer 40

Silica Sand and silver fuse links

Question 41

Function of the conductor shield within a HV cable is to?

Answer 41

prevent corona

Question 42

Mositure and contaminants on the insualtion of a HV cable could casue tracking and eventually flashover. T/F

Answer 42

True

Question 43

Conductor shield overcomes problems of ionized air between conductor strands and insulation. T/F

Answer 43

True

Question 44

Grounded shield act to protect life in the event of mechanical damage to cable. T/F

Answer 44

False

Question 45

Splicing HV cable is easeier then terminating it. T/F

Answer 45

False

Question 46

What CB has a very high dielectric strength surrounding its main contacts and the shortest contact travel when opening?

Answer 46

Vacuum CB

Question 47

Lightning arrestor is connected to HV line, cable, busbar for the purpose of?

Answer 47

removing excess charge that might appear on the line

Question 48

High potential testing may be done with either AC or DC what is most common?

Answer 48

DC because it doesnt require large power supply as AC

Question 49

When does the Modiewark HV detector give a signal?

Answer 49

When the fuse is blown

Question 50

What role does insulation shield serve in a HV cable?

Answer 50

Prevent flux line concentrations from occurring

Question 51

Purpose of corona rings in HV transmission lines?

Answer 51

To reduce corona discharge

Question 52

Two most undesirable effects caused by corona on overhead lines?

Answer 52

Power losses and RFI

Question 53

Purpose of the conductor shield is to ensure that the flux lines do not pass through the flux lines> T/F

Answer 53

True

Question 54

What determines the distance the semi con mut be cut back from the termination of the lug?

Answer 54

System voltage