Question 1

The field contactor contains a DC coil and is energized by the ____________________ current of the rotor.

Accepted Answer

excitation

Question 2

What is phase paper?

Accepted Answer

Phase paper is insulating paper added to the terminal leads that exit the motor. Inverter rated motors generally have phase paper added to the terminal leads. The high voltage spikes affect the beginning lead of a coil much more than the wire inside the coil. The coil is an inductor that naturally opposes a change of current. Most of the insulation stress caused by high voltage spikes occurs at the beginning of a winding.

Question 3

The difference between rotor speed and synchronous speed (speed of the rotating magnetic field) is called ____ and is measured as a percentage.

Accepted Answer

A)  wound 
B)  slip 
C)  pole 
D)  hertz 
A)  wound 
B)  slip 
C)  pole 
D)  hertz B

Question 4

In a variable frequency drive, the ____ control sets the maximum speed of the motor.

Accepted Answer

A)  minimum hertz 
B)  maximum hertz 
C)  current limit 
D)  volts per hertz 
A)  minimum hertz 
B)  maximum hertz 
C)  current limit 
D)  volts per hertz

Question 5

Give an overview of alternator control.

Accepted Answer

Alternators are often used to control th

Question 6

The alternator is turned by a direct current motor or an AC motor coupled to a(n) ____________________ current clutch.

Accepted Answer

The answer of The alternator is turned by a direct...

Question 7

How does frequency control operate?

Accepted Answer

Frequency control operates on

Question 8

Many transistor controlled variable frequency drives now employ a special type of transistor called an ____ Bipolar Transistor (IGBT).

Accepted Answer

A)  Inductive Gate 
B)  Inductive Gas 
C)  Insulated Gas 
D)  Insulated Gate 
A)  Inductive Gate 
B)  Inductive Gas 
C)  Insulated Gas 
D)  Insulated Gate

Question 9

When normal excitation has been achieved, the power factor will be ____ percent.

Accepted Answer

A)  10 
B)  33 
C)  66 
D)  100 
A)  10 
B)  33 
C)  66 
D)  100

Question 10

The wound rotor motor was the first alternating-current motor that permitted speed control.

Accepted Answer

A) True 
 B)False

Question 11

Small synchronous motors generally contain ____ slip rings on the rotor shaft.

Accepted Answer

A)  zero 
B)  two 
C)  four 
D)  six 
A)  zero 
B)  two 
C)  four 
D)  six

Question 12

A decrease in frequency produces a decrease in inductive reactance.

Accepted Answer

A) True 
 B)False

Question 13

How do synchronous motors differ from squirrel-cage and wound rotor induction motors?

Accepted Answer

Characteristics that make synchronous mo

Question 14

The starting current and speed of a wound rotor induction motor is controlled by adding or subtracting the amount of ____________________ connected in the rotor circuit.

Accepted Answer

The answer of The starting current and speed of a...

The field contactor contains a DC coil and is energized by the ____________________ current of the rotor.

What is phase paper?

The difference between rotor speed and synchronous speed (speed of the rotating magnetic field) is called ____ and is measured as a percentage.

In a variable frequency drive, the ____ control sets the maximum speed of the motor.

Give an overview of alternator control.

The alternator is turned by a direct current motor or an AC motor coupled to a(n) ____________________ current clutch.

How does frequency control operate?

Many transistor controlled variable frequency drives now employ a special type of transistor called an ____ Bipolar Transistor (IGBT).

When normal excitation has been achieved, the power factor will be ____ percent.

The wound rotor motor was the first alternating-current motor that permitted speed control.

Small synchronous motors generally contain ____ slip rings on the rotor shaft.

A decrease in frequency produces a decrease in inductive reactance.

How do synchronous motors differ from squirrel-cage and wound rotor induction motors?

The starting current and speed of a wound rotor induction motor is controlled by adding or subtracting the amount of ____________________ connected in the rotor circuit.

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

Basic Control Circuits and Photodetectors

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

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 22: Variable Frequency Control

The field contactor contains a DC coil and is energized by the ____________________ current of the rotor.

What is phase paper?

The difference between rotor speed and synchronous speed (speed of the rotating magnetic field) is called ____ and is measured as a percentage.

In a variable frequency drive, the ____ control sets the maximum speed of the motor.

Give an overview of alternator control.

The alternator is turned by a direct current motor or an AC motor coupled to a(n) ____________________ current clutch.

How does frequency control operate?

Many transistor controlled variable frequency drives now employ a special type of transistor called an ____ Bipolar Transistor (IGBT).

When normal excitation has been achieved, the power factor will be ____ percent.

The wound rotor motor was the first alternating-current motor that permitted speed control.

Small synchronous motors generally contain ____ slip rings on the rotor shaft.

A decrease in frequency produces a decrease in inductive reactance.

How do synchronous motors differ from squirrel-cage and wound rotor induction motors?

The starting current and speed of a wound rotor induction motor is controlled by adding or subtracting the amount of ____________________ connected in the rotor circuit.

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

Basic Control Circuits and Photodetectors

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

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