Question 1

Plugging controls provide for the rapid stop and quick reversal of motor rotation.

Accepted Answer

Plugging controls allow for quick stopping and reversing of motor rotation by reversing the direction of the applied voltage, which causes the motor to rapidly decelerate and start rotating in the opposite direction. Plugging controls cut off the supply to the motor, causing it to stop quickly and allowing for quick reversal of rotation.

Question 2

Plugging switches are also known as__________ switches.
A)temperature
B)zero-speed
C)pressure
D)limit

Accepted Answer

Plugging switches are also known as zero-speed switches because they are used to detect the stoppage or extremely low speed of a mechanical system, thereby preventing plugging or jamming.

Question 3

The plugging switch may be driven by gears, by a chain drive, or a __________coupling.
A)welded half
B)direct rigid
C)welded current
D)direct flexible

Accepted Answer

A direct flexible coupling allows for some misalignment between two rotating shafts while still transmitting power efficiently. This type of coupling is commonly used in situations where slight vibrations or misalignment can occur, making it a suitable choice for a plugging switch. A direct flexible coupling allows for some misalignment between the driving and driven components, which is important in applications where the alignment between the two may not be perfect. Welded half and welded current couplings do not allow for any misalignment, while a direct rigid coupling allows for very little misalignment.

Question 4

A time-delay relay may be used in a motor plugging circuit.

Accepted Answer

A time-delay relay can be used in a motor plugging circuit to delay the switching of the direction of current flow to protect the motor and prevent damage caused by rapid reversal of current. A time-delay relay can be used to control the delay in turning off a motor in a plugging circuit, which is a method of quickly stopping a motor by reversing the direction of its rotation. The relay can be set to delay the signal for turning off the motor in order to ensure that it is fully stopped before power is disconnected.

Question 5

Standard reversing controllers cannot be plugged manually.

Accepted Answer

Standard reversing controllers are designed to allow manual plugging or reversing of the motor direction by interchanging connections, typically through a manual switch or control mechanism.

Question 6

In ________cases, the machines controlled by plugging switches will be driven by squirrel cage motors.
A)a very few
B)some
C)most
D)all

Accepted Answer

Squirrel cage motors are commonly used in industrial settings as they are less expensive and simpler to maintain compared to other types of motors. Therefore, it is likely that in most cases, machines controlled by plugging switches will be driven by squirrel cage motors.

Question 7

The torque that operates the plugging switch contacts will vary according to the speed of the motor.

Accepted Answer

This is because the torque of the motor is directly proportional to its speed, so as the speed of the motor changes, the torque exerted on the plugging switch contacts will also change. This is true as the torque applied by the motor to the plugging switch will vary depending on its speed. A higher motor speed will generate more torque, while a lower speed will generate less torque.

Question 8

You can predetermine the direction of the rotation of motors when the phases are connected externally in proper sequence.

Accepted Answer

The answer of You can predetermine the direction of the...

Question 9

Antiplugging protection is obtained when a device prevents the application of a counter torque until the motor speed ____.
A)decreases to zero
B)is reduced to an acceptable value
C)decreases below a preset limit
D)increases above a preset limit

Accepted Answer

The answer of Antiplugging protection is obtained when a device...

Question 10

The lockout relay provides a mechanical means of preventing the switch contacts from closing_________ the motor starting circuit is energized.
A)unless
B)if
C)if and only if
D)even if

Accepted Answer

The lockout relay is designed to prevent the switch contacts from closing unless the motor starting circuit is energized. This ensures that the motor is not started unintentionally, which could be dangerous for both the equipment and the personnel operating it. The lockout relay prevents the switch contacts from closing unless the motor starting circuit is energized. This is to ensure that there is no accidental start of the motor, which can lead to unsafe situations.

Quiz 48: Plugging

Plugging controls provide for the rapid stop and quick reversal of motor rotation.

Plugging switches are also known as__________ switches.

The plugging switch may be driven by gears, by a chain drive, or a __________coupling.

A time-delay relay may be used in a motor plugging circuit.

Standard reversing controllers cannot be plugged manually.

In ________cases, the machines controlled by plugging switches will be driven by squirrel cage motors.

The torque that operates the plugging switch contacts will vary according to the speed of the motor.

You can predetermine the direction of the rotation of motors when the phases are connected externally in proper sequence.

Antiplugging protection is obtained when a device prevents the application of a counter torque until the motor speed ____.

The lockout relay provides a mechanical means of preventing the switch contacts from closing_________ the motor starting circuit is energized.