Ch. 8 Phase II

The two wiring connectors on the typical ECM blower motor are for what function?

Line-voltage AC power input and low voltage control signals

On the control module on an electronically commutated motor, when is line voltage alternating current supplied?

At all times

The ECM is a brushless DC, three phase motor with a _________ rotor.

Permanent magnet

Of the motors listed which has the highest operating efficiency?

Electronically commutated motor

In a residential heating and cooling system with a variable speed fan it had which of the following type of motor?

ECM

The resistance in a three-phase motor vs a smaller motor, the larger motors with typically have __________ resistance.

Lower

Three-phase motors are simpler than many types of single-phase motors because they do not require…

All of the choices are correct

how many electrical degrees of separation are there between each of the phases being supplied to a three-phase motor?

120 degrees

What will be the result if the starting relay contacts fail to open because of a bad relay coil for a CSR motor?

The starting capacitor will be destroyed

If there was a CSR motor what is the main function of the run capacitor?

Increase the running efficiency of the motor

The action of magnetic polarities could best be described as…

Unlike polarities attract each other

Coiling wire around an iron core will result in what action?

All choices are correct

To produce rotation in an electric motor what is required?

Rotating magnetic field

This part of an electric motor produces the rotating magnetic field to enable the motor to rotate.

Stator

This rotating part of an electric motor produces an inductive magnetic field within itself when the motor is energized.

Squirrel-cage rotor

When selecting a motor for a specific application what motor characteristics must be considered?

All of the choices are correct

When a motor is turning the force or strength it produces is called…

Torque

What motor has the highest starting torque?

Three-Phase

What motor would be used for a low torque application for aa small propeller fan?

Shaded-pole

Of the motors listed which will have the highest rotational speed?

Two-pole motor

What will be the speed of a 10-pole motor operating on 230v/1ph/60Hz

720 rpm

An example of an enclosed motor would be which of the following?

Hermetic compressor motor

On a NEMA Frame 56 motor, the center of the shaft to the mounting surface is __________ inches.

3 1/2

This motor has a heavy copper conductor banded around a section of each stator pole.

Shaded-pole

What motor does not have a starting winding?

Three-phase

What facilitates the initial rotation of a shaded pole motor?

Shaded-pole

A shaded pole motor rotational direction is ___________.

Toward the shaded pole

In order to reverse the rotation of a shaded-pole motor what must be done?

Disassembled the motor and reverse the stator

This electrical device can store electrons on two aluminum plates that have an insulator between them is a…

Capacitor

This unit is used to measure the strength or capacitance of a capacitor.

Microfarads