Single Phase Motors

To calculate the synchronous speed of an induction motor, you need to know the _____ of the power supply and the ______ in the motor

Frequency; number of poles

What in a power line is the short circuit protective device for a motor?

Fuse or circuit breaker

If a windings makes electrical contact with the stator case, the winding is?

Grounded

If you have problems with a split phase motor, you should test both windings for _______, ________, and ___________

Grounds, open circuits, short circuits

A _________ must be established in a capacitor-start motor to produce the starting torque

Rotating magnetic field

What is the name for the rotating part of a motor? For the stationary part?

Rotor; Stator

In an induction motor, a potential difference is induced in the _____ by the _____ of the stator

Rotor; magnetic field

The end plate bearings support the _____ and keep it centered within the _______

Rotor; stator

Are the coils in the stator winding would in the same direction when the motor is manufactured, or in opposite directions?

Same direction

In dual-voltage split-phase motors, the coils are connected in ________ for 240V and in _______ for 120V

Series; parallel

A split phase motor can be made to run as a capacitor-start motor by connecting a capacitor in ______ with the ______ winding

Series; start

Which kind of motor has one or more short-circuited auxiliary windings that are displaced from the main winding

Shaded pole motor

Which winding normally has higher resistance in a split phase motor?

Start

In a split phase induction motor, the wire in the __________ winding is smaller than the wire in the _________ winding

Start; run

One coil pitch of a coil is defined as the number of ________ a coil spans.

Stator slots

A single phase induction motor can be made self starting by adding a second?

Stator winding

Slip speed is the difference between a motor's _____ speed and its ______ speed

Synchronous; operating

Which rotates faster in an induction motor, the magnet or the disk?

The magnet

A capacitor start capacitor run motor having two different values of capacitance is called a _______ motor

Two-valve capacitor

In a split phase motor the start-winding current _______ the run-winding current, but it _________ the applied potential difference

leads; lags

Which connections must you reverse to reverse the direction of rotation in a split phase motor?

Either start or run

What kind of capacitor has polarity markings, and must not be used in AC circuits

Electrolytic

which of the following is not part of a rotor?

End plates

What governs the speed of an induction motor?

Frequency of the power supply; Number of poles

What is the synchronous speed of a six pole motor running on power at 50HZ

1000 RPM

AC motors are designed to operate at +___% of their rated potential difference and +____% of their rated frequency

10; 5

A dual voltage motor can operate on either _______V or _______V

120,240

What is the NEMA designation for a motor having normal starting torque, normal starting current, high breakdown torque, and low slip?

A

Single-phase induction motors are noisy, because the rotating magnetic field ________

Pulsates

In a split phase motor, any two ________ poles must have the opposite magnetic. polarity?

Adjacent

What cools the windings in an open motor?

Air

The service factor of a motor is defined as the

Allowable overload

A ________ can give the same symptoms as worn or dry bearings

Bent rotor shaft

What is an indication that a motor shaft has overheated?

Blue color

The maximum torque a motor can produce without an abrupt decrease in speed is called its ________ torque

Breakdown

A ______ is a device that can store an electrical charge

Capacitor

What device may be used for disconnecting the start winding in a single-phase induction motor

Centrifugal switch, magnetic relay, thermal relay

A _______ pole forms as a consequence of a formation of another magnetic pole

Consequent

How long can most motors run without overheating?

Continuously

Which of the following is not a method used for identifying motor leads in a single-phase motor?

Counting the number of stator poles

Which of the following ohmmeter readings indicates an open circuit in a split-phase motor winding

Infinite reading

A _______ reading on an ohmmeter indicates and open circuit. A _______ reading indicates the winding is not open

Infinite; Low

If two identical windings are connected in parallel to an AC source, the currents in the windings will both ________ the potential difference

Lag

Can a symmetrically wound single-phase induction motor start by itself?

No

If two identical windings are connected to a single phase source, will their combined magnetic field rotate?

No

Any two adjacent poles have the opposite polarity.

No matter how many poles the motor has

A megohmmeter reading of 1 Mega-ohm or more means the winding is?

Not grounded

To change the speed of a split phase motor, you must change the ________

Number of poles

For starting a split phase motor the run and start windings are connected in

Parallel

In order to complete on AC cycle, a conductor must move

Past two magnetic poles

In a motor or generator, how far must a conductor move in order to complete one cycle?

Past two poles

All of the following are open motors, expect the _______ motor

Waterproof

Can a standard motor made by one manufacturer be replaced by the same standard motor made by another manufacturer?

Yea

A standard split phase motor is used for applications that require ______ starting and _______ operating periods

frequent; long

How many coils are required in a consequent-pole motor having a total of four poles?

two

how many coils are required in a consequent-pole motor having a total of four poles?

two