Deck 19: Three-Phase Motor Installations

Question 1

A(n) ____________________ starts like a two-phase motor from a single-phase line, and it operates on the running winding as a single-phase induction motor after the motor accelerates to a value near its rated speed.

Answer 1

split-phase motor
split phase motor

Question 2

A(n) ____________________, which includes a thermistor as the sensing device, is used effectively for arcless switching of the starting winding in a split-phase induction motor.

Answer 2

electronic relay
solid-state relay
solid state relay

Question 3

The direction of rotation of the split-phase motor is normally reversed by interchanging the leads of the ____________________ winding.

Answer 3

starting

Question 4

Name two types of external starting switches.

Question 5

What are the main components of a split-phase induction motor?

Question 6

The type of capacitor-start, capacitor-run motor that has two capacitors has a very good starting torque, good speed regulation, and a power factor of nearly 100% at rated load.

Question 7

The capacitor-start induction motor is used on refrigeration units, compressors, oil burners, and for small machine equipment, as well as for other applications that require a strong starting torque.

Question 8

The capacitor of a capacitor-start motor provides a higher starting torque than is obtainable with the standard split-phase motor and also limits the starting surge of current to a lower value than is developed by the standard split-phase motor.

Question 9

The capacitor-start, ____________________ motor features the starting winding and capacitor connected in the circuit at all times.

Question 10

Briefly explain how a single phase motor with dual-voltage ratings of 115 volts and 230 volts is operated on 230 volts.

Question 11

The starting torque of the split-phase motor is comparatively high.

Question 12

The principle of operation of ____________________ motors uses the effects of induction not only into the squirrel-cage rotor, but also into parts of the stator that create a rotating magnetic field from a single phase of input voltage.

Question 13

Briefly explain why many motor manufacturers recommend that a capacitor-start motor be started no more than 20 times per hour?

Question 14

A split-phase motor requires that only the starting winding is energized when the motor is started.

Question 15

Name two applications for capacitor-start induction motors.