Question 1

What should you be wary of when coordinating high-voltage fusings?

Accepted Answer

Coordination studies require that the time-current characteristic of the different protective devices be compared and that the selection of the proper devices be made accordingly. Problems in the coordination of high-voltage fusing occur most frequently when:
1. circuit breakers are used as secondary protective devices, and
2. a single main protective device is installed on the secondary side of the transformer.

Question 2

The autotransformer is designed to provide voltage components to the potential coils of the reactive meter. These voltage components are________ degrees out of phase with the line voltage.

Accepted Answer

A)  45 
B)  90 
C)  180 
D)  270 
A)  45 
B)  90 
C)  180 
D)  270 B

Question 3

The decimal impedance in a transformer is found by determining the ratio of the source voltage as compared to the rated voltage of the________ winding.

Accepted Answer

A)  high-voltage 
B)  variable-voltage 
C)  low-voltage 
D)  short circuit 
A)  high-voltage 
B)  variable-voltage 
C)  low-voltage 
D)  short circuit A

Question 4

High-voltage fuses are available with either an N or a(n)________ rating.

Accepted Answer

A)  B 
B)  C 
C)  D 
D)  E 
A)  B 
B)  C 
C)  D 
D)  E

Question 5

A device called a________ provides a reliable method of terminating a high-voltage cable.

Accepted Answer

A)  lighting arrester 
B)  pothead 
C)  grounding bus 
D)  secondary bus 
A)  lighting arrester 
B)  pothead 
C)  grounding bus 
D)  secondary bus

Question 6

What role do taps play?

Accepted Answer

Although voltage systems are generally c

Question 7

________is the process of selecting protective devices so that there is a minimum of power interruption in case of a fault or overload.

Accepted Answer

A)  Transformation 
B)  Masking 
C)  Coordination 
D)  Correlation 
A)  Transformation 
B)  Masking 
C)  Coordination 
D)  Correlation

Question 8

If the primary current is less than two amperes for a transformer rated at 600 volts or less, the short-circuit protective device can be set at not more than________ percent of this value.

Accepted Answer

A)  100 
B)  200 
C)  300 
D)  400 
A)  100 
B)  200 
C)  300 
D)  400

Question 9

Discuss the role and location of the grounding bus.

Accepted Answer

The majority of the connections to groun

Question 10

How do you select a fuse with the correct continuous current rating to provide transformer protection?

Accepted Answer

The selection of the fuse with the corre

Question 11

Connections between the current and potential transformers in the high-voltage section of the unit substation and the autotransformer and meter sockets in the cabinet are made with size 12 ________wire.

Accepted Answer

A)  Music Wire Gauge 
B)  US Steel Wire Gauge 
C)  W&M Wire Gauge 
D)  American Wire Gauge 
A)  Music Wire Gauge 
B)  US Steel Wire Gauge 
C)  W&M Wire Gauge 
D)  American Wire Gauge

Question 12

A 600-volt to 200-volt transformer would become a 600-volt to ________-volt transformer if the connections were reversed.

Accepted Answer

A)  100 
B)  300 
C)  1200 
D)  1800 
A)  100 
B)  300 
C)  1200 
D)  1800

Question 13

After the incoming voltage is reduced to the desired value, it is taken________ by into the low-voltage section.

Accepted Answer

A)  busbars 
B)  grounding buses 
C)  terminals 
D)  secondary buses 
A)  busbars 
B)  grounding buses 
C)  terminals 
D)  secondary buses

Question 14

Rate reductions are made by the power company when the metering measurements are taken on the ________side of the transformer.

Accepted Answer

A)  high-voltage 
B)  variable-voltage 
C)  low-voltage 
D)  secondary bus 
A)  high-voltage 
B)  variable-voltage 
C)  low-voltage 
D)  secondary bus

Question 15

The step-down transformers, metering, and switching equipment necessary to supply the low voltage loads to the customer are housed in a________ .

Accepted Answer

A)  unit substation 
B)  grounding bus 
C)  terminal 
D)  secondary bus 
A)  unit substation 
B)  grounding bus 
C)  terminal 
D)  secondary bus

Question 16

An alternative to grounding the secondary is to let it________ ; that is, the secondary remains ungrounded.

Accepted Answer

A)  sink 
B)  float 
C)  surface 
D)  exit 
A)  sink 
B)  float 
C)  surface 
D)  exit

Question 17

The________ of a transformer is the winding that is connected to a voltage source.

Accepted Answer

A)  ammeter 
B)  secondary 
C)  primary 
D)  short circuit 
A)  ammeter 
B)  secondary 
C)  primary 
D)  short circuit

Question 18

Lightning arresters are designed to provide a(n) ________path to ground for any surge currents such as those resulting from a lightning strike.

Accepted Answer

A)  high impedance 
B)  low-impedance 
C)  indirect 
D)  intermittent 
A)  high impedance 
B)  low-impedance 
C)  indirect 
D)  intermittent

Question 19

The rates charged by the power company for the energy used are based on the readings of the meter registers and the________ indicators.

Accepted Answer

A)  maximum demand 
B)  short circuit 
C)  terminal 
D)  ampere 
A)  maximum demand 
B)  short circuit 
C)  terminal 
D)  ampere

Question 20

What is the procedure for terminating an incoming high-voltage cable?

Accepted Answer

To connect the incoming lead-covered cab

Exam 2: The Unit Substation

What should you be wary of when coordinating high-voltage fusings?

The autotransformer is designed to provide voltage components to the potential coils of the reactive meter. These voltage components are________ degrees out of phase with the line voltage.

The decimal impedance in a transformer is found by determining the ratio of the source voltage as compared to the rated voltage of the________ winding.

High-voltage fuses are available with either an N or a(n)________ rating.

A device called a________ provides a reliable method of terminating a high-voltage cable.

What role do taps play?

________is the process of selecting protective devices so that there is a minimum of power interruption in case of a fault or overload.

If the primary current is less than two amperes for a transformer rated at 600 volts or less, the short-circuit protective device can be set at not more than________ percent of this value.

Discuss the role and location of the grounding bus.

How do you select a fuse with the correct continuous current rating to provide transformer protection?

Connections between the current and potential transformers in the high-voltage section of the unit substation and the autotransformer and meter sockets in the cabinet are made with size 12 ________wire.

A 600-volt to 200-volt transformer would become a 600-volt to ________-volt transformer if the connections were reversed.

After the incoming voltage is reduced to the desired value, it is taken________ by into the low-voltage section.

Rate reductions are made by the power company when the metering measurements are taken on the ________side of the transformer.

The step-down transformers, metering, and switching equipment necessary to supply the low voltage loads to the customer are housed in a________ .

An alternative to grounding the secondary is to let it________ ; that is, the secondary remains ungrounded.

The________ of a transformer is the winding that is connected to a voltage source.

Lightning arresters are designed to provide a(n) ________path to ground for any surge currents such as those resulting from a lightning strike.

The rates charged by the power company for the energy used are based on the readings of the meter registers and the________ indicators.

What is the procedure for terminating an incoming high-voltage cable?

Plans and Sitework

Feeder Bus System

Panelboards

Trolley Busways

Using Wire Tables and Determining Conductor Sizes

Signaling Systems

Basic Motor Controls

Motors and Controllers

Motor Installation

Power Factor

Ventilating, Air Conditioning, and Other Facilities

System Protection

Lightning Protection

Luminaires

Site Lighting

Programmable Logic Controllers

Developing a Program for a Plc

Fiber Optics

Hazardous Locations

Harmonics

Filters