Question 1

Limit switches are used to detect when an object is present or absent from a particular location.

Accepted Answer

A) True 
 B)False  True

Question 2

Describe the subminiature micro switch.

Accepted Answer

The subminiature micro switch employs a similar spring contact arrangement as the basic micro switch. The subminiature switches are approximately one-half to one-quarter the size of the basic switch, depending on the model. Due to their reduced size, the contact ratings of subminiature switches range from about 1 ampere to about 7 amperes depending on the switch type.

Question 3

Discuss unbalanced voltage.

Accepted Answer

Motors are intended to operate on systems with balanced voltage (the voltage is the same between all phases). Unbalanced voltage is one of the leading causes of motor failure. Unbalanced voltage is generally caused when single-phase loads are supplied by three-phase systems.

Question 4

What is the role of bumper arms?

Accepted Answer

Limit switches contain some type of bump

Question 5

The type of bumper arm used is determined by the ____ of the limit switch.

Accepted Answer

A)  location 
B)  contact arrangement 
C)  application 
D)  size 
A)  location 
B)  contact arrangement 
C)  application 
D)  size

Question 6

Electrical ratings for the contacts of the basic micro switch are generally in the range of ____ volts AC.

Accepted Answer

A)  75 
B)  100 
C)  150 
D)  250 
A)  75 
B)  100 
C)  150 
D)  250

Question 7

The percentage of heat rise in the motor caused by the voltage unbalance is equal to ____ times the percent squared.

Accepted Answer

A)  two 
B)  three 
C)  four 
D)  five 
A)  two 
B)  three 
C)  four 
D)  five

Question 8

____________________ phasing will cause the two phases that remain energized in a three-phase motor to increase current by an average of 173 percent.

Accepted Answer

The answer of ____________________ phasing will cause the two phases...

Question 9

Motors are intended to operate on systems with balanced voltage.

Accepted Answer

A) True 
 B)False

Question 10

Micro switches are used in small spaces that would never be accessible to a larger device.

Accepted Answer

A) True 
 B)False

Question 11

If two of the lines supplying power to a three-phase motor are reversed, the motor will not reverse the direction of rotation.

Accepted Answer

A) True 
 B)False

Question 12

What problems can unintended reversal of direction cause?

Accepted Answer

Unintended reversal of direction can cau

Question 13

NEMA recommends that the unbalanced voltage not exceed plus or minus ____________________ percent.

Accepted Answer

The answer of NEMA recommends that the unbalanced voltage not...

Limit switches are used to detect when an object is present or absent from a particular location.

Describe the subminiature micro switch.

Discuss unbalanced voltage.

What is the role of bumper arms?

The type of bumper arm used is determined by the ____ of the limit switch.

Electrical ratings for the contacts of the basic micro switch are generally in the range of ____ volts AC.

The percentage of heat rise in the motor caused by the voltage unbalance is equal to ____ times the percent squared.

____________________ phasing will cause the two phases that remain energized in a three-phase motor to increase current by an average of 173 percent.

Motors are intended to operate on systems with balanced voltage.

Micro switches are used in small spaces that would never be accessible to a larger device.

If two of the lines supplying power to a three-phase motor are reversed, the motor will not reverse the direction of rotation.

What problems can unintended reversal of direction cause?

NEMA recommends that the unbalanced voltage not exceed plus or minus ____________________ percent.

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

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

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 6: Limit Switches and Phase Failure Relays

Limit switches are used to detect when an object is present or absent from a particular location.

Describe the subminiature micro switch.

Discuss unbalanced voltage.

What is the role of bumper arms?

The type of bumper arm used is determined by the ____ of the limit switch.

Electrical ratings for the contacts of the basic micro switch are generally in the range of ____ volts AC.

The percentage of heat rise in the motor caused by the voltage unbalance is equal to ____ times the percent squared.

____________________ phasing will cause the two phases that remain energized in a three-phase motor to increase current by an average of 173 percent.

Motors are intended to operate on systems with balanced voltage.

Micro switches are used in small spaces that would never be accessible to a larger device.

If two of the lines supplying power to a three-phase motor are reversed, the motor will not reverse the direction of rotation.

What problems can unintended reversal of direction cause?

NEMA recommends that the unbalanced voltage not exceed plus or minus ____________________ percent.

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

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

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