Motor Controls test 2
A commutator rotates in____° increments.
180
Horsepower is a unit of power equal to____lb-ft per minute.
33,000
A motor with a service factor of 1.0 is derated when it operates at altitudes above _____.
3300
When they split-phase Motor reaches approximately____% of full speed, the centrifugal switch opens, disconnecting the starting winding from the circuit.
75
Full-wave rectified power is obtained by placing a(n) _____in an AC power line.
Bridge rectifier
A DC series motor is a DC motor that has the series field connected in series with the_____.
Brushes
DC motors require more maintenance than AC motors because they have____that wear.
Brushes
A(n) _____ Motor has a starting winding in capacitor connected in series at all times.
Capacitor-run
The capacitor used in the starting winding gives a____motor high starting torque.
Capacitor-start
A spring place behind the brush forces the brush to make contact with the____.
Commutator
The wires extending from the shunt field of a DC shunt motor are marked _____.
F1 and F2
A DC motor consist of_____winding, an armature, a commutator, and brushes.
Field
The intensity of the magnetic field in the amount of current in a conductor are normally change to increase the____on the conductor.
Force
A duel-voltage, wye-connected motor has _____ separate circuits.
Four
The maximum recommended acceleration time depends on the motor___size.
Frame
The____of a motor should be grounded, especially if the motor is used in a damp location.
Frame
The____of a motor determines the size of a load that the motor can operate in the speed at which the load trends.
Horsepower
A(n) _____ should be used for more accurate testing of insulation.
Megohmmeter
The electron flow motor rule states that the _______ points in the direction of the electron current flow in the conductor.
Middle finger
In a DC shunt Motors, if the_____to the armature is reduce, the speed is also reduced.
Voltage
______is produced when a force overcomes a resistance.
Work
All capacitors are made with two conductive surfaces separated by_____.
dielectric material
A(n) _____ is a sensor that produces discrete electrical pulses drawing each increment of shaft rotation.
encoder
A(n) _____is used to increase or decrease in strength of the field or armature in a DC shunt motor.
rheostat
The____is the base unit of electrical power.
watt
_____ wear faster than any other component of a DC motor.
Brushes
Most DC motors are designed so that the brushes and the____can be inspected without disassembling the motor.
Commutator
When starting a split-phase motor, both the running windings and starting windings are____.
Connected in parallel
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
A commutator connects each armature winding to the brushes using____bars that are insulated from each other with pieces of mica.
Copper
Motors operate on the principle that when ________ -carrying conductor is placed in a magnetic field, a force that tends to move the conductor out of the field is exerted on the conductor.
Current
Stepper motors are used in applications that require precise control of the position of the____.
Motor shaft
An electrician can observe the even blackening of all motor windings that occurs when a motor has failed due to _____.
Overloading
When the motor is first connected to power, the____of the starting winding is lower and the resistance is higher than the running winding.
Reactance
In a stepper motor, the permanent magnet is called the____or armature.
Rotor
A DC_____motor should always be connected directly to the load and not through belts, chains, etc.
Series
Terminal marking S1 and S2 always indicate the___field leads.
Series
______ motor that fail are usually replaced.
Shaded-pole
___the stator Paul is the simplest method used to start a one phase motor.
Shading
A(n) ___circuit is a circuit in which current takes a shortcut around the normal path of current flow
Short
To help reduce damage to switch contacts, a(n) _____ circuit is used to protect the switch.
Snubber
Because the stator call oils are turned on and off rapidly to control a stepper motor,____switches are used.
Solid-state transistor
The requirements a motor must meet in controlling a load include work, force, torque, and horsepower in rotation to____.
Speed
Some ___Motors include a thermal switch that automatically turns the motor off when it overheats.
Split-phase
The____is the stationary part of an AC motor.
Stator
The direction of shaft rotation is controlled by the polarity of the produce magnetic field in the_____.
Stator coil
To develop a rotating magnetic field in a 3 phase motor, the _____ must be connected to the proper voltage level.
Stator winding
In a 3 phase motor, the leads that or raw how externally or the label with a(n) _____.
T
The____that is produced by motor depends on the strength of the magnetic field in the motor.
Torque
____Is exerted on an armature when it is positioned so that the plane of the armature loop is parallel to the field, and the armature loop sides are at right angles to the magnetic field.
Torque
____Is the force that produces rotation.
Torque