Deck 10: Three-Phase Systems

Question 1

The voltage across the line wires is called the end-to-end voltage.

Answer 1

False

Question 2

The induced voltage in each phase winding is called the ____________________ voltage.

Answer 2

phase

Question 3

Describe a two-phase, four-wire system.

Answer 3

This system consists of two separate single-phase circuits. These circuits are isolated electrically from each other.

Question 4

In a three-phase, four-wire, wye-connected circuit, the ____________________ wire helps to maintain relatively constant voltages across the three sections of the wye-connected load when the currents are unbalanced.

Question 5

Describe power measurement in three-phase systems.

Question 6

What are the conditions that the total three-phase power, in watts, can be determined?

Question 7

According to the three-wattmeter method, what is the total power taken by a three-phase, four-wire system?

Question 8

Most alternating-current energy is generated by three-phase generators.

Question 9

Describe the wye connection.

Question 10

The line current and the phase winding current are the same.

Question 11

Many wye-connected systems have a(n) ____________________ wire in addition to the three line wires.

Question 12

The phase ____________________ is the order in which the three voltages of a three-phase circuit follow one another.

Question 13

When three-phase voltage is connected to a three-phase motor, a rotating magnetic field is produced inside the motor.

Question 14

The armature in the wye connection is called the ____________________.

Question 15

In a balanced three-phase circuit, the power factor is always the sine of the angle between the coil voltage and the coil current.