single phase
Many split-phase motors are designed for operation on ____.
120v or 240v
Multispeed fan motors have been used for many years and are generally wound for ____ steps of speed and operate fans and squirrel-cage blowers.
2 to 5
The normal dual-voltage rating of industrial motors is ___ V.
230/460
A brush-lifting motor uses a radial commutator, and weights are mounted at the front of the armature. When the motor reaches about ____% of full speed, these weights swing outward due to centrifugal force and cause two push rods to act against a spring barrel and short-circuiting necklace.
75
___ motors that fail are usually replaced.
Shaded pole
A shaded-pole induction motor is popular because of its simplicity and long life.
True
In a split-phase motor, synchronous speed is determined by the same two factors that determined the synchronous speed for a three-phase motor: number of stator poles per phase and frequency of the applied voltage.
True
When oiling a motor, oil should be applied to the ___ only.
bearings
A(n) ___ motor has the starting winding and capacitor connected in series at all times.
capacitor run
The capacitor used in the starting winding gives a ___ motor high starting torque.
capacitor-start
Motors that are not hermetically sealed use a ____ switch to disconnect the start windings from the circuit.
centrifugal
When starting a split-phase motor, both the running windings and the starting windings are ___.
connected in parallel
All capacitors are made with two conducting surfaces separated by ___.
dielectric material
Stepping motors are devices that convert ____ into mechanical movement.
electrical impulses
A consequent pole motor is used where high running torque must be maintained at one constant speed.
false
A two-phase system is produced by having an alternator with two sets of coils wound 180 degrees apart.
false
Although a capacitor-start induction-run motor has a high starting torque, the motor should not be started more than two times per hour.
false
The ___ of a motor should be grounded, especially if the motor is used in a damp location.
frame
There are three basic repulsion motors: repulsion motor, repulsion-start ____ motor, and repulsion-induction motor.
induction run
The direction of rotation for a split-phase motor is determined by the direction of rotation of the magnetic field created by the run and start windings when the motor ____.
is first started
An electrician can observe the even blackening of all motor windings that occurs when a motor has failed due to ___.
overloading
When a motor is first connected to power, the ___ of the starting winding is lower and the resistance is higher than the running winding.
reactance
The stator of a split-phase motor contains two separate windings, the start winding and the ____ winding.
run
___ the stator pole is the simplest method used to start a 1Ö motor.
shading
The ___ is the stationary part of an AC motor.
stator
To develop a rotating magnetic field in a 3Ö motor, the ___ must be connected to the proper voltage level.
stator windings
Single-phase ____ motors operate on the principle of a rotating magnetic field developed by a shaded-pole stator. Although they will operate at synchronous speed, they do not require DC excitation current.
synchronous
A repulsion-start induction-run motor starts as a repulsion motor but runs as a squirrel-cage motor.
true
In a capacitor-start capacitor-run motor, a capacitor is connected in series with the winding to provide a continuous leading current in the start winding.
true
A(n) ___ may be used to determine the winding circuits on an unmarked motor by connecting one test lead to any motor lead and temporarily connecting the other test lead to each remaining motor lead.
continuity tester
The speed of a shaded-pole induction motor is determined by the same factors that determine the synchronous speed of other induction motors—____ and number of stator poles.
frequency
When a split-phase motor reaches approximately ___% of full speed, the centrifugal switch opens, disconnecting the starting winding from the circuit.
75
The maximum recommended acceleration time depends on the motor ___ size.
Frame
