Question 1

What is the relationship between three-wire control circuits and momentary contact devices?

Accepted Answer

Three-wire control circuits are characterized by the use of momentary contact devices such as push buttons. When push buttons control the operation of a motor, three wires are run from the push-button control station to the starter.

Question 2

What are some advantages of three-wire control circuits?

Accepted Answer

Three-wire control is used to a much greater extent throughout the industry than two-wire control because of its flexibility. Pilot control devices such as push buttons, float switches, and limit switches can be mounted in remote locations, whereas the motor starter can be located close to the motor it controls or in a control cabinet with other control components. Another advantage of three-wire control circuits is that, in the event of a power failure, they will not restart automatically when power is restored. This can be a major safety issue in many instances.

Question 3

Two-wire control circuits control the operation of three-phase motors by controlling the power applied to the motor ____.

Accepted Answer

A)  starter coil 
B)  stator 
C)  shaft 
D)  bearing 
A)  starter coil 
B)  stator 
C)  shaft 
D)  bearing A

Question 4

Control circuits can be divided into two major types: three-wire control circuits and four-wire control circuits.

Accepted Answer

A) True 
 B)False

Question 5

Three-wire controls depend on a set of normally open contacts, generally called ____________________, maintaining, or sealing contacts.

Accepted Answer

The answer of Three-wire controls depend on a set of...

Question 6

Common voltage values for motor starter coils (in volts AC) are: 24, 120, 208, 240, 277, 480, and 560.

Accepted Answer

A) True 
 B)False

Question 7

List some advantages of using a photodetector.

Accepted Answer

Photodetectors do not have to make physi

Question 8

In a control circuit for a hot water boiler, a(n) ____________________-limit temperature switch will stop the burner if the water temperature should become excessive.

Accepted Answer

The answer of In a control circuit for a hot...

Question 9

What is a cad cell?

Accepted Answer

The most common photoconductive device i

Question 10

Photoemissive devices emit ____________________ when in the presence of light.

Accepted Answer

The answer of Photoemissive devices emit ____________________ when in the...

Question 11

Photo-operated devices fall into one of three categories: photovoltaic, photoemissive, and ____.

Accepted Answer

A)  photomagnetic 
B)  photoresistive 
C)  photoconductive 
D)  alternative 
A)  photomagnetic 
B)  photoresistive 
C)  photoconductive 
D)  alternative

Question 12

The transmitter section of a photodetector is the light source, which is generally a long life ____ bulb.

Accepted Answer

A)  fluorescent 
B)  halogen 
C)  LED 
D)  incandescent 
A)  fluorescent 
B)  halogen 
C)  LED 
D)  incandescent

Question 13

____ voltage controls are simply controls that do not employ the use of a control transformer to change the voltage to a lower value.

Accepted Answer

A)  Varistor 
B)  Line 
C)  Three-wire 
D)  Float 
A)  Varistor 
B)  Line 
C)  Three-wire 
D)  Float

Question 14

Photodetectors can be used to sense the presence or absence of almost any object.

Accepted Answer

A) True 
 B)False

What is the relationship between three-wire control circuits and momentary contact devices?

What are some advantages of three-wire control circuits?

Two-wire control circuits control the operation of three-phase motors by controlling the power applied to the motor ____.

Control circuits can be divided into two major types: three-wire control circuits and four-wire control circuits.

Three-wire controls depend on a set of normally open contacts, generally called ____________________, maintaining, or sealing contacts.

Common voltage values for motor starter coils (in volts AC) are: 24, 120, 208, 240, 277, 480, and 560.

List some advantages of using a photodetector.

In a control circuit for a hot water boiler, a(n) ____________________-limit temperature switch will stop the burner if the water temperature should become excessive.

What is a cad cell?

Photoemissive devices emit ____________________ when in the presence of light.

Photo-operated devices fall into one of three categories: photovoltaic, photoemissive, and ____.

The transmitter section of a photodetector is the light source, which is generally a long life ____ bulb.

____ voltage controls are simply controls that do not employ the use of a control transformer to change the voltage to a lower value.

Photodetectors can be used to sense the presence or absence of almost any object.

General Principles of Motor Control, Symbols and Schematic Diagrams

Manual Starters and Overload Relays

The Control Transformer, Relays, Contactors, and Motor Starters

Timing Relays, Pressure Switches and Sensors

Float Switches, Flow Switches and Sensors

Limit Switches and Phase Failure Relays

Temperature Sensing, Devices M Solenoid and Motor Operated Valves

Hall Effect Sensors and Proximity Detectors

Schematics, Wiring Diagrams Circuit (1), Timed Starting for Three Motors Circuit (2)

Float Switch Control of a Pump and Pilot Lights Circuit (3), Developing a Wiring Diagram Circuit (1)

Developing a Wiring Diagram Circuit (2) and Developing a Wiring Diagram Circuit (3)

Installing Control Systems and Reading Large Schematic Diagrams

Multiple Push Button Stations and Hand-Off-Automatic Controls

Forward-Reverse Control, Jogging and Inching

Dc Motors and Sequence Control

Solid-State Dc Drives and Starting Methods for DC Motors

Stepping Motors, the Motor and Starting Methods

Autotransformer Starting , Resistor and Reactor Starting for Ac Motors

Wye-Delta Starting, Part Winding Starters

Braking , Consequent Pole Motors, Variable Voltage and Magnetic Clutches

Variable Frequency Control

Troubleshooting, Motor Installation and Developing Control Circuits

Digital Logic and the Bounceless Switch

Programmable Logic Controllers and Start-Stop Push Button Control

Programming a PLC and Analog Sensing for Programmable Controllers

Filters

Exam 9: Basic Control Circuits and Photodetectors

What is the relationship between three-wire control circuits and momentary contact devices?

What are some advantages of three-wire control circuits?

Two-wire control circuits control the operation of three-phase motors by controlling the power applied to the motor ____.

Control circuits can be divided into two major types: three-wire control circuits and four-wire control circuits.

Three-wire controls depend on a set of normally open contacts, generally called ____________________, maintaining, or sealing contacts.

Common voltage values for motor starter coils (in volts AC) are: 24, 120, 208, 240, 277, 480, and 560.

List some advantages of using a photodetector.

In a control circuit for a hot water boiler, a(n) ____________________-limit temperature switch will stop the burner if the water temperature should become excessive.

What is a cad cell?

Photoemissive devices emit ____________________ when in the presence of light.

Photo-operated devices fall into one of three categories: photovoltaic, photoemissive, and ____.

The transmitter section of a photodetector is the light source, which is generally a long life ____ bulb.

____ voltage controls are simply controls that do not employ the use of a control transformer to change the voltage to a lower value.

Photodetectors can be used to sense the presence or absence of almost any object.

General Principles of Motor Control, Symbols and Schematic Diagrams

Manual Starters and Overload Relays

The Control Transformer, Relays, Contactors, and Motor Starters

Timing Relays, Pressure Switches and Sensors

Float Switches, Flow Switches and Sensors

Limit Switches and Phase Failure Relays

Temperature Sensing, Devices M Solenoid and Motor Operated Valves

Hall Effect Sensors and Proximity Detectors

Schematics, Wiring Diagrams Circuit (1), Timed Starting for Three Motors Circuit (2)

Float Switch Control of a Pump and Pilot Lights Circuit (3), Developing a Wiring Diagram Circuit (1)

Developing a Wiring Diagram Circuit (2) and Developing a Wiring Diagram Circuit (3)

Installing Control Systems and Reading Large Schematic Diagrams

Multiple Push Button Stations and Hand-Off-Automatic Controls

Forward-Reverse Control, Jogging and Inching

Dc Motors and Sequence Control

Solid-State Dc Drives and Starting Methods for DC Motors

Stepping Motors, the Motor and Starting Methods

Autotransformer Starting , Resistor and Reactor Starting for Ac Motors

Wye-Delta Starting, Part Winding Starters

Braking , Consequent Pole Motors, Variable Voltage and Magnetic Clutches

Variable Frequency Control

Troubleshooting, Motor Installation and Developing Control Circuits

Digital Logic and the Bounceless Switch

Programmable Logic Controllers and Start-Stop Push Button Control

Programming a PLC and Analog Sensing for Programmable Controllers

Filters