week 2 (chapters 4-5)

Question 1

provides information on how to store, transport, install, maintain, and inventory the unit?

Answer 1

nameplate

Question 2

lineman use the nameplate to ensure?

Answer 2

primary voltage is chosen
secondary is chosen
impedence is within +/- 10%
weight

Question 3

where is the nameplate typically found?

Answer 3

overhead: on or near lower mounting bracket
underground: inside door on the face

Question 4

a nameplate with a primary coil voltage printed last and H1A H1B bushings in the schematic is what type of transformer?

Answer 4

underground

Question 5

the primary coil voltage is always ________ of the two voltages?

Answer 5

smaller

Question 6

most useful information on the nameplate?

Answer 6

voltage ratings
KVA
serial
polarity
impedance
schematic

Question 7

always check the _________ to determine proper ________ before installing

Answer 7

nameplate/voltages

Question 8

always verify the __________ _______ with an approved voltmeter before connecting the customer’s load.

Answer 8

secondary voltage

Question 9

transformer manufactures comply with _____ standard C57.12.00 when designating winding voltage ratings?

Answer 9

ANSI

Question 10

what are the three ways transformers can be purchased according to their primary voltage designations?

Answer 10

phase to phase only
phase to ground only
phase to phase / phase to ground

Question 11

a nameplate with only one number listed for the primary voltage is a ______ connection.

Answer 11

Delta

Question 12

phase to phase is synonymous with what connection type?

Answer 12

Delta

Question 13

when using a transformer for both delta and wye connections, no matter what connection type is used, the primary voltage is still going to be?

Answer 13

the smaller of the two voltages

Question 14

when ever you see GRDY on a nameplate, it is automatically a _____ connection

Answer 14

Wye

Question 15

duel rated transformers have what function?

Answer 15

two primary coil ratings

Question 16

an external no-load switch is found on a ___________ transformer?

Answer 16

dual-rated

Question 17

the duel voltage switch must only be operated when?

Answer 17

when the transformer is de-energized

Question 18

tap changing transformers only effect the voltages to the?

Answer 18

customers

Question 19

provides the same secondary voltage at different points on the system where primary voltage may not be the same?

Answer 19

tap changers

Question 20

depending on the manufacturer, each tap raises or lowers the secondary voltage by ?

Answer 20

2.5 or 4.5 %

Question 21

is the tap changer connected to the primary or secondary coil?

Answer 21

primary

Question 22

an audible sound should not be heard between the ______ and _______ windings when conducting a continuity test.

Answer 22

primary/secondary

Question 23

what is used to test insulation of a transformer?

Answer 23

megger

Question 24

what test is done with the low input voltage connected to the high voltage winding?

Answer 24

turns ration testing

Question 25

a transformer with only one primary bushing would be a ______ connection?

Answer 25

Wye

Question 26

H1 to phase/H2 to phase is a _______ connection?

Answer 26

Delta

Question 27

a nameplate has 7200/12470Y for primary voltages and the system voltage is 4160/7200. is this a delta or wye connection?

Answer 27

Delta (small to large primary)

Question 28

a transformer has “7200” as the primary winding rating. is it delta or wye connection?

Answer 28

Delta (phase to phase)