Ch 5 & 6

Question 1

Coil of a transformer energized from AC source.

Answer 1

Primary Winding

Question 2

What causes an expanding and collapsing field in the core?

Answer 2

AC voltage applied to primary windings

Question 3

The expanding and collapsing magnetic field induces voltage in what?

Answer 3

Secondary windings wrapped around the core

Question 4

The output from the secondary windings is the same frequency as what? And goes where?

Answer 4

Primary windings. Load.

Question 5

Transferring energy to an electrically isolated circuit.

Answer 5

Mutual Inductance

Question 6

Coil that delivers AC to the load.

Answer 6

Secondary Winding

Question 7

When voltage is increased, Current is?

Answer 7

Decreased and vice versa

Question 8

Inductor produces self induced EMF that opposes applied voltage.

Answer 8

CEMF

Question 9

Functions of Transformers?

Answer 9

Step up step down AC voltages

Provide isolation between source and load.

Question 10

Primary distribution that connects load breakers to power source.

Answer 10

Electrical Bus

Question 11

Device that consumes electrical power.

Answer 11

Electrical load

Question 12

Electrical component that is essential to operation of a system that performs a vital function.

Answer 12

Vital/Essential Load

Question 13

Centralized distribution and control point for 480 vac loads.

Answer 13

Motor Control Center

Question 14

What helps prevent accidents to personnel?

Answer 14

Equipment Grounding

Question 15

Reduces voltage and functions as centralized pt for distribution of power.

Answer 15

Substation

Question 16

Transforms high voltage power to a level that can be used by loads in the system.

Answer 16

Distribution Transformer

Question 17

Removal of any part of a power system that suffers an electrical fault by energizing the trip circuit.

Answer 17

Protective Relays

Question 18

Protects component from overcurrent.

Answer 18

Fuse

Question 19

3 Purposes of Circuit Breakers

Answer 19

Maintenance isolation

Open circuit for protection and provide normal switching without damaging circuit.

Starter for large motors

Question 20

Low voltage breaker components

Answer 20

Operating mechanism 
Main contacts/arching contacts 
Arc extinguisher
Tripping mechanism 
Terminal connectors

Question 21

Breaker positions

Answer 21

Racked in
Racked out
Test

Question 22

Breaker Indicators

Answer 22

Circuit breaker positioning indicating lights

Circuit breaker positioning indicating flag

Question 23

Breaker Safety Features

Answer 23

Rack in out / test positions 
Arc extinguisher 
Automatic trip 
Trip free operating mechanism 
Quick make quick break 
Open/closed tripping indicators

Question 24

Control and protect the operation of a motor.

Answer 24

Motor Controllers

Question 25

Deenergize motor during low voltage condition and prevent it from starting automatically upon restoration.

Answer 25

LVP Controller

Question 26

Deenergize motor during low voltage condition and restarts motor upon restoration.

Answer 26

LVR Controller

Question 27

Maintains motor across the line at all times.

Answer 27

LVRE Controller

Question 28

3 features of manual controllers for small loads

Answer 28

Small size Automatic restart upon power restoration Low cost

Question 29

Magnetic controller protective devices

Answer 29

Low voltage | Over current or overload

Question 30

What proves overload protection?

Answer 30

Manual controllers

Question 31

Two position switches used for isolation of power to loads.

Answer 31

Disconnect Switches

Question 32

Automatically transfers essential loads from normal power source to an alternate power source when normal power lost.

Answer 32

Automatic Transfer Switches

Question 33

Designed to prefer one power source over any other.

Answer 33

Normal seeking transfer switch

Question 34

This switch does not make the distinction between power sources.

Answer 34

Power seeking transfer switches

Question 35

480 v distribution system indications

Answer 35

1. Transformer Voltmeter - voltage on the line. 2. Transformer Ammeter - Current output of transformer. 3. Transformer demand watt-hour - displays highest output power. 4. Switchgear bus voltmeter - voltage on switch gear bus bar.

Question 36

Small distribution panels that provide power at either 120 v or 208 v.

Answer 36

Panel Board

Question 37

Electrical problems such as overloads, short circuits and open circuits.

Answer 37

Electrical Fault

Question 38

Assembly of circuit breakers that are electrically connected to a system of buses.

Answer 38

Switchgear

Question 39

Power from the normal source, 115 kv at site.

Answer 39

Normal Power

Question 40

Furnished power to all vital/essential loads.

Answer 40

SDG Power

Question 41

Conducting connection between a circuit and the earth. Human body can serve as the earth and complete connection.

Answer 41

Ground

Question 42

Protective Relays

Answer 42

``` Differential relay Over voltage relay Under voltage relay Thermal overload relay Instantaneous OC relay Instantaneous ground OC relay ```