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

Explore all topics

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.

Free

(Multiple Choice)

4.7/5

(38)

Question 1

Correct Answer:

Verified

What is reactor starting?

Free

(Essay)

5.0/5

(39)

Question 2

Correct Answer:

Verified

A reactor starter is the same basic control except that reactors or choke coils are used to limit in-rush current instead of resistors. Reactors limit in-rush current with inductive reactance instead of resistance. Reactors have an advantage in current-limiting circuits because of the rise time of current in an inductive circuit. In a resistive circuit, the current will reach its full Ohm's Law value instantly. In an inductive circuit, the current must rise at an exponential rate. This exponential rise time of current further reduces the in-rush current.

Autotransformer starters are generally employed to start ____ -type motors.

Free

(Multiple Choice)

4.9/5

(44)

Question 3

Correct Answer:

Verified

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

(True/False)

4.9/5

(37)

Question 4

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

(Short Answer)

4.8/5

(43)

Question 5

When the coil of S contactor energizes, all S contacts ____.

(Multiple Choice)

4.8/5

(44)

Question 6

What is open transition starting and when is it used?

(Essay)

4.8/5

(39)

Question 7

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

(Short Answer)

4.8/5

(34)

Question 8

Discuss the use of taps in autotransformer starters.

(Essay)

4.9/5

(37)

Question 9

Current ____ are used to sense the amount of motor current.

(Multiple Choice)

4.8/5

(40)

Question 10

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

(Essay)

5.0/5

(41)

Question 11

Most autotransformer starters use two transformers connected in ____________________ delta.

(Short Answer)

4.7/5

(37)

Question 12

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

(True/False)

4.9/5

(46)

Question 13

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

(True/False)

4.8/5

(29)

Question 14

Showing 1 - 14 of 14

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.

What is reactor starting?

Autotransformer starters are generally employed to start ____ -type motors.

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

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

When the coil of S contactor energizes, all S contacts ____.

What is open transition starting and when is it used?

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

Discuss the use of taps in autotransformer starters.

Current ____ are used to sense the amount of motor current.

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

Most autotransformer starters use two transformers connected in ____________________ delta.

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

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

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

Limit Switches and Phase Failure Relays

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

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