Offline Copies of Chapter Quizzes
Terms and Definitions – Self Test 1
Questions
Using the above diagram, answer questions 1 to 5:
- Which letter identifies the component that normally provides overcurrent protection for the motor branch circuit?
- Which letter identifies the component that normally provides overload protection for the motor branch circuit?
- When energized by the control circuit, which letter identifies the component that provides normal starting and stopping actions?
- Between which two letters is the control circuit power normally taken from?
- Which letter(s) identify devices that must be horsepower rated?
- A melting alloy type of thermal overload is called a:
- Solder-pot relay
- Dash-pot relay
- Thermal relay
- Bimetallic relay
- The part of a manual AC motor starter which senses motor overload current is the:
- High-limit switch
- Solder-pot assembly
- Overload contact
- Heater element
- If automatic starting after a power failure represents a safety hazard for a motor drive, it should be equipped with:
- Low voltage release
- A flashing red light
- Low-voltage protection
- A warning sign
- An overload relay that uses a strip of dissimilar metals is called a _______ relay
- Melting alloy
- Thermistor
- Solder pot
- Bimetallic
- Referring to the drawing, assuming that fuse C is blown, which pair of points will result in a reading of zero volts when the voltmeter is connected across them?
- To connect a motor solely for jogging operation, the control circuit will:
- Use holding contacts
- Connect holding contacts in series with the start button
- Connect holding contacts in parallel with the start button
- Not use holding contacts
- Timed relays are the best method to provide plugging for a motor. True or false?
- The electrical interlocks in a reversing magnetic starter are:
- Controlled by the timing relays necessary for circuit operation
- In parallel with the forward and reverse pushbuttons
- Normally closed contacts
- Normally open contacts
- Overload protection for motors is achieved by connecting:
- Thermal sensing elements in series with the motor
- A reset relay in series with the motor
- Cartridge fuses in series with the motor
- A set of N.C contacts in series with the motor
- With a three-wire control circuit, when power is restored after a low voltage situation:
- An operator must restart the motor
- The motor will polyphase
- The motor will automatically restart
- The motor will automatically restart after a time delay
Answers
- B
- D
- C
- B and C
- A and C
- A
- D
- C
- A
- 3 and 6
- D
- False
- C
- A
- A
Pilot Devices – Self Test 2
Questions
- In a motor control circuit with multiple start/start pushbutton stations, the stop buttons would be connected in ______ and the start buttons would be connected in _______.
- To troubleshoot an electrical control circuit, the best drawing to be used would be:
- Schematic
- Wiring
- Pictorial
- RIser
- A double contact pushbutton is illustrated below. When connected as a start button in the control circuit of a magnetic starter, which pair of terminals are normally utilized?
- Timed relays are the best method to provide plugging for a motor. True or false?
Answers
- Series, parallel
- A
- 3 and 4
- False
Motor Starters and Contactors – Self Test 3
Questions
- The minimum number of control circuit conductors to a stop/forward/reverse pushbutton station that provides low-voltage protection for a three-phase reversible motor is:
- 2 wires
- 3 wires
- 4 wires
- 6 wires
- Which of the following type of motor starter does not normally provide running protection for the motor?
- A magnetic starter
- A pushbutton starter
- A toggle-switch starter
- A drum-switch controller
- If the circuit in the drawing was operating normally and an overload occurred, then:
- Both lights would come on
- The green light would come on, and the red light would go out
- Both lights would go out
- The red light would come on, and the green light would go out
- With a three-wire control circuit, when power is restored after a low voltage situation:
- The motor will automatically restart after a time delay
- The motor will automatically restart
- An operator must restart the motor
- The motor will polyphase
- A melting alloy type of thermal overload is called a:
- Solder-pot relay
- Thermal relay
- Bimetallic relay
- Dash-pot relay
- A starter rated at 10HP, 600 V, if used on a 120V motor would most likely be rated at:
- 2 HP
- 3 HP
- 10 HP
- 2.5 HP
- A N.C.T.C contact will be open immediately after the coil is de-energized. True or false?
- An overload relay that uses a strip of dissimilar metals is called a _______ relay
- Thermistor
- Melting alloy
- Solder pot
- Bimetallic
- A shading coil is not required for a DC voltage coil. True or false?
- Overload protection for motors is achieved by connecting:
- A set of N.C contacts in series with the motor
- Thermal sensing elements in series with the motor
- Cartridge fuses in series with the motor
- A reset relay in series with the motor
- The part of a manual AC motor starter which senses motor overload current is the:
- Overload contact
- Solder-pot assembly
- Heater element
- High-limit switch
- The essential difference between a magnetic motor starter and a magnetic contactor is that the contactor does not contain:
- Shading coils
- Holding contacts
- Overload relay protection
- Horsepower-rated contacts
- The rotation of an AC three-phase induction motor may be reversed by interchanging:
- The control circuit
- The forward/reverse interlocks
- The forward reverse coils
- Any two power lines
- If an AC magnetic contactor with a 480V coil was energized with 120V, then most likely the:
- Overload relay would trip
- Contactor would not pick up
- Control circuit fuses would blow
- Coil would overheat during normal operation
- In a control schematic, a dotted line between two coils generally means that the two coils:
- Are operated together
- Are mechanically interlocked
- Are electrically interlocked
- Have a common set of contacts
- During normal operation, a loud chattering noise is heard from the enclosure of an AC magnetic starter. What is the most likely cause?
- Broken shading coil
- Open in the seal-in circuit
- Rust on pole faces
- Power contact is not making good contact due to poor pressure
- The purpose of electrical interlocking in a three-phase reversing AC magnetic motor starter is to:
- Ensure that the forward direction of rotation is selected first
- Allow both coils to be energized together
- Prevent both coils from being energized simultaneously
- Maintain the coil circuit after the stop button is released
- A double-contact pushbutton is illustrated below. When connected as a start button in the control circuit of a magnetic starter, which pair of terminals are normally used?
- A time-delay relay includes both timed and instantaneous contacts. True or false?
- Fill in the missing words. The electrical interlocks on a reversing starter are normally _______ contacts
- A N.O.T.O contact will be closed while the coil of the relay is energized. True or false?
- A N.C.T.O designation refers to an off-delay timer. True or false?
- The electrical interlocks in a reversing magnetic starter are:
- Normally closed contacts
- Normally open contacts
- In parallel with the forward and reverse pushbuttons
- Controlled by the timing relays necessary for circuit operation
Answers
- D
- C
- D
- C
- A
- A
- False
- D
- True
- B
- C
- C
- D
- B
- B
- A
- C
- 3 and 4
- True
- Closed
- True
- False
- A
Diagrams – Self Test 4
Questions
Using the above diagram, answer questions 1 to 5:
- Which letter identifies the component that normally provides overcurrent protection for the motor branch circuit?
- Which letter identifies the component that normally provides overload protection for the motor branch circuit?
- When energized by the control circuit, which letter identifies the component that provides normal starting and stopping actions?
- Between which two letters is the control circuit power normally taken from?
- Which letter(s) identify devices that must be horsepower rated?
- In a motor control circuit with multiple start/start pushbutton stations, the stop buttons would be connected in ______ and the start buttons would be connected in _______.
- To troubleshoot an electrical control circuit, the best drawing to be used would be:
- Schematic
- Pictorial
- Wiring
- RIser
- A drawing which shows the relative locations of various components is a:
- Wiring diagram
- Schematic diagram
- Elementary diagram
- Ladder diagram
- Referencing the following drawing, what is the number of wires required where indicated?
Answers
- B
- D
- C
- B and C
- A and C
- Series, parallel
- A
- A
- 3
Circuits – Self Test 5
Questions
Using the following diagram, answer questions 1 to 5:
- Which letter identifies the component that normally provides overcurrent protection for the motor branch circuit?
- Which letter identifies the component that normally provides overload protection for the motor branch circuit?
- When energized by the control circuit, which letter identifies the component that provides normal starting and stopping actions?
- Between which two letters is the control circuit power normally taken from?
- Which letter(s) identify devices that must be horsepower rated?
- The minimum number of control circuit conductors to a stop/forward/reverse pushbutton station that provides low-voltage protection for a three-phase reversible motor is:
- 2 wires
- 3 wires
- 4 wires
- 6 wires
- Inching is another term used for:
- Jogging
- Plugging
- Shunting
- Hunting
- The rotation of an AC three-phase induction motor may be reversed by interchanging:
- The control circuit
- The forward/reverse interlocks
- The forward reverse coils
- Any two power lines
- In a control schematic, a dotted line between two coils generally means that the two coils:
- Are operated together
- Are mechanically interlocked
- Are electrically interlocked
- Have a common set of contacts
- The purpose of electrical interlocking in a three-phase reversing AC magnetic motor starter is to:
- Ensure that the forward direction of rotation is selected first
- Allow both coils to be energized together
- Prevent both coils from being energized simultaneously
- Maintain the coil circuit after the stop button is released
- To connect a motor solely for jogging operation, the control circuit will:
- Use holding contacts
- Connect holding contacts in series with the start button
- Connect holding contacts in parallel with the start button
- Not use holding contacts
- In regards to the drawing, the best label for the pushbutton labelled “Z” would be:
- Stop
- Jog
- Run
- Reset
- In regards to the drawing, the best label for pushbutton “Y” would be:
- Stop
- Jog
- Run
- Reset
Use the following image to answer questions 14 and 15.
- What is the minimum number of control circuit conductors required in Conduit A?
- 2 wires
- 3 wires
- 4 wires
- 5 wires
- What is the minimum number of control circuit conductors required in Conduit B?
- 2 wires
- 3 wires
- 4 wires
- 5 wires
- Timed relays are the best method to provide plugging for a motor. True or false?
- A time-delay relay includes both timed and instantaneous contacts. True or false?
- A N.C.T.C contact will be open immediately after the coil is de-energized. True or false?
- A N.O.T.O contact will be closed while the coil of the relay is energized. True or false?
- A N.C.T.O designation refers to an off-delay timer. True or false?
- The electrical interlocks in a reversing magnetic starter are:
- Normally closed contacts
- Normally open contacts
- In parallel with the forward and reverse pushbuttons
- Controlled by the timing relays necessary for circuit operation
- Overload protection for motors is achieved by connecting:
- Thermal sensing elements in series with the motor
- A reset relay in series with the motor
- Cartridge fuses in series with the motor
- A set of N.C contacts in series with the motor
- Jogging refers to a:
- Motor that is not capable of developing constant torque
- Motor that is polyphasing
- Motor that periodically starts and stops
- Method used to stop a motor for exact positioning
Answers
- B
- D
- C
- B and C
- A and C
- C
- A
- D
- B
- C
- D
- B
- C
- ?
- C
- False
- True
- False
- True
- False
- A
- A
- D
Troubleshooting – Self Test 6
- A drawing which shows the relative locations of various components is a:
- Wiring diagram
- Schematic diagram
- Elementary diagram
- Ladder diagram
- To ensure safety for maintenance, the motor disconnecting switch must be locked in the “OFF” position. After the maintenance work is completed, the lock is removed by:
- The supervisor
- The project manager
- The person who put the lock on
- The lead hand
- With regard to workers safety, “isolation” refers to:
- Moving to a remote location
- Disconnect from all energy sources
- Turn off the electrical switch
- Fence off the work site
- Referring to the drawing, assuming that fuse C is blown, which pair of points will result in a reading of zero volts when the voltmeter is connected across them?
- The disconnecting means which is NOT intended for interrupting current flow is the:
- Motor switch
- General use switch
- Isolating switch
- Circuit breaker
- If the circuit in the drawing was operating normally and an overload occurred, then:
- Both lights would come on
- The green light would come on, and the red light would go out
- Both lights would go out
- The red light would come on, and the green light would go out
- During normal operation, a loud chattering noise is heard from the enclosure of an AC magnetic starter. What is the most likely cause?
- Broken shading coil
- Open in the seal-in circuit
- Rust on pole faces
- Power contact is not making good contact due to poor pressure
- If the control circuit shown below tripped due to overload, then which of the voltmeter positions shown would indicate line voltage?
- VM A
- VM B
- VM C
- VM D
- What is the minimum number of control circuit conductors required in Conduit A?
- 2 wires
- 3 wires
- 4 wires
- 5 wires
- An isolating switch can be used as a motor power circuit disconnect switch. True or false?
Use the following image to answer questions 11 and 12.
- If the motor starter in the drawing is energized and functioning properly, what should the voltage be across the normally open contact (M)?
- Line voltage
- Zero voltage
- Half of line voltage
- Twice line voltage
- If the motor starter in the drawing is energized and functioning properly, what should be the voltage across the N.C contact (M)?
- Line voltage
- Zero voltage
- Half of line voltage
- Twice line voltage
Answers
- A
- C
- B
- 3 and 6
- C
- D
- A
- ?
- ?
- False
- B
- A