3 Phase Dual Voltage Motors

What is the most common Poly Phase electrical service in Industry?

• single phase

• three phase

• four phase

• two phase

Three phase power contains 3 voltage waveforms separated by 90 electrical degrees.

• True

• False

What are poles?

• are the electromagnets used to produce magnetic fields

• are how we identify the different phases

• measure of frequency

Which of the following is the formula for calculating synchronous speed?

• $s=120\times\frac{P}{f}$

• $s=P\times\frac{120}{f}$

• $s=120\times\frac{f}{P}$

What is true about synchronous speed?

• a theoretical speed not met by Induction motors

• a speed met by Synchronous motors

• the speed of a rotating magnetic field in a motor

Three phase motors work using the operating principle of a rotating magnetic field.

• True

• False

Dual voltage motors are the most common 3 phase motors used in Industry.

• True

• False

Which of the following is advantages of Dual Voltage Motors?

• Technician can wire the motor to whatever voltage is nearby

• Higher voltages require less current and smaller conductors

• Higher voltages are more dangerous

High Voltage services are common in Commercial and Residential building.

• True

• False

How many wires are used in a Wye(Star) connection?

• 3

• 4

• 5