Question 1

The starting transformers are inductive loads.

Accepted Answer

Transformers have inductance due to the presence of coils or windings in their construction. Therefore, they are considered as inductive loads. Transformers are inductive loads because they require a magnetic field to be produced in order to transfer energy from the primary winding to the secondary winding. This magnetic field is generated by the flow of current through the winding, which creates an electromagnetic field. Inductive loads such as transformers store energy in this magnetic field, which can cause a lag in the current waveform and require reactive power.

Question 2

In an autotransformer-type starter the timing for the time-delay relay that controls the transfer from the reduced voltage condition to full voltage is not adjustable.

Accepted Answer

In an autotransformer-type starter, the timing for the time-delay relay that controls the transfer from the reduced voltage condition to full voltage is typically adjustable, allowing for customization based on the specific starting requirements of the motor or application.

Question 3

Starting compensators using a five-pole starting contactor are classified as .&#10;A)autotransformer starters&#10;B)open transition starters&#10;C)secondary Resistors&#10;D)semiautomatic Starters

Accepted Answer

Starting compensators using a five-pole starting contactor are classified as open transition starters. Autotransformer starters use an autotransformer to reduce the starting current and secondary resistors use resistors to limit the starting current. Semiautomatic starters are not a type of starting compensator. Starting compensators using a five-pole starting contactor are classified as open transition starters. The other options, autotransformer starters, secondary resistors, and semiautomatic starters, have different methods for starting the motor.

Question 4

De-energizing the transformers while in the running position is done to conserve electrical energy.

Accepted Answer

The answer of De-energizing the transformers while in the running...

Question 5

Current transformers are used on large motor starters to step down the current so that a conventional overload relay and heater may be used.&#10;A)size&#10;B)design&#10;C)arrangement&#10;D)connection

Accepted Answer

Current transformers are used to step down the current to a lower level so that conventional overload relays and heaters of a standard size can be used, ensuring compatibility and safety in electrical systems.

Question 6

Magnetic overload relays are used on large reduced voltage starters.

Accepted Answer

Magnetic overload relays are commonly used on large reduced voltage starters to protect the motor from overheating due to overloads or faults. Magnetic overload relays are used on large reduced voltage starters to provide overload protection for the motor.

Question 7

In an autotransformer-type starter, autotransformers supply of the line voltage to the motor.&#10;A)45%&#10;B)55%&#10;C)65%&#10;D)75%

Accepted Answer

Autotransformers supply 65% of the line voltage to the motor.

Question 8

Starting transformers momentarily affect the .&#10;A)service factor&#10;B)auxiliary equipment&#10;C)power factor&#10;D)motor stability

Accepted Answer

Starting transformers cause an inrush current which affects the power factor of the system. This is because the inrush current is leading and has a capacitive effect on the system, which can result in a lower power factor. The service factor, auxiliary equipment, and motor stability are typically not directly affected by starting transformers.

Question 9

Most motors are successfully started at 90 percent of line voltage.

Accepted Answer

Most motors are designed to operate at their rated voltage, and starting a motor at 90 percent of line voltage may not provide sufficient torque to start the motor. It is recommended to start motors at their rated voltage or using a soft starter device that gradually increases the voltage to avoid damage to the motor. Most motors are designed to operate at their rated voltage, which means they should be started at 100 percent of line voltage. Starting a motor at only 90 percent of line voltage could result in insufficient torque and damage to the motor over time.

Question 10

Closed transition connections are usually found on standard size and larger starters.&#10;A)5&#10;B)6&#10;C)7&#10;D)8

Accepted Answer

Closed transition connections are typically used on starters of size 6 and larger. Closed transition connections are usually found on starters of size 6 and larger.

Deck 27: Autotransformer Starters