Question 1

Autotransformer starters increase the amount of inrush current by reducing the voltage applied to the motor during the starting period.

Accepted Answer

Autotransformer starters reduce the amount of inrush current by reducing the voltage applied to the motor during the starting period, which makes the starting process smoother and less stressful on the electrical system.

Question 2

Autotransformer starters are generally employed to start ____ -type motors.&#10;A) synchronous&#10;B) squirrel-cage&#10;C) noninduction&#10;D) wound rotor

Accepted Answer

Autotransformer starters are generally employed to start squirrel-cage induction motors because they allow for reduced voltage starting, which reduces the inrush current and the mechanical stress on the motor during startup.

Question 3

When the coil of S contactor energizes, all S contacts ____.&#10;A) retract&#10;B) change position&#10;C) de-energize&#10;D) remain in position

Accepted Answer

When the coil of an S contactor energizes, all S contacts change position. This means normally open (NO) contacts will close, and normally closed (NC) contacts will open.

Question 4

Most autotransformer starters use two transformers connected in ____________________ delta.

Accepted Answer

The answer of Most autotransformer starters use two transformers connected...

Question 5

When the motor reaches the ____________________ stage, it is connected directly to the power line and the autotransformer is completely disconnected from the circuit.

Accepted Answer

The answer of When the motor reaches the ____________________ stage,...

Question 6

Discuss the use of taps in autotransformer starters.

Accepted Answer

The answer of Discuss the use of taps in autotransformer...

Question 7

What is open transition starting and when is it used?

Accepted Answer

The answer of What is open transition starting and when...

Question 8

Resistor starting and reactor starting differ in the means used to reduce the amount of torque.

Accepted Answer

Resistor starting and reactor starting both aim to reduce the initial current during the start-up of electric motors, but the means they use are different: resistor starting uses resistors to limit the current, while reactor starting uses inductors (reactors) to limit the current. Both methods indirectly affect the torque, as torque is related to current, but the primary goal is to reduce current, not directly to alter torque.

Question 9

Some circuits may use several steps of starting, depending on the circuit requirements.

Accepted Answer

Some circuits, especially those controlling large motors or complex machinery, use multiple steps of starting to gradually apply power, manage torque, and reduce inrush currents, thus meeting specific operational requirements and protecting the equipment.

Question 10

Current ____ are used to sense the amount of motor current.&#10;A) resistors&#10;B) varistors&#10;C) capacitors&#10;D) transformers

Accepted Answer

Current transformers are used to sense the amount of motor current by stepping down the current to a lower, more manageable level for measurement or monitoring purposes.

Question 11

Some resistor and reactor starters use multiple steps of starting. This is accomplished by tapping the resistor or reactor to provide different values of resistance or ____ reactance.&#10;A) transformer&#10;B) current&#10;C) inductive&#10;D) resistive

Accepted Answer

The answer of Some resistor and reactor starters use multiple...

Question 12

Current rises at a(n) ____________________ rate in an inductive circuit.

Accepted Answer

The answer of Current rises at a(n) ____________________ rate in...

Question 13

When is it impossible to start a motor across the line?

Accepted Answer

The answer of When is it impossible to start a...

Question 14

What is reactor starting?

Accepted Answer

The answer of What is reactor starting?...

Deck 19: Autotransformer Starting , Resistor and Reactor Starting for Ac Motors