DC
Rotating electromagnet located between fixed poles.
What is an armature
Type of motor used when a wide variation in both torque and speed are required
What is a series motor
Two classes of polyphase motors
What are synchronous and induction
Calculation for the synchronous speed of a polyphase motor
What is 120f / Number of poles
How to reverse the direction of rotation of a 3-phase induction motor
What is reversing any two connections
Has more starting torque than a split phase motor
What is a capacitor type
Indicates locked rotor KVA per HP
What is the KVA code
Reverses the direction of current flow through the armature.
What is the commutator
Reversing either the armature or field winding current flow in a series motor
What is change of direction
Stator windings in a polyphase motor are displaces by this amount
What is 120 deg.
The amount of slip the moment the motor is energized
What is 100%
Changes with a change in line frequency
What is RPM
Provides higher efficiency and power factor and lower line current
What is a run capacitor
Indicates the temperature rating of the winding insulation
What is insulation class
These lines do not cross
What are magnetic lines of force
Usually connected to loads directly of through gears
What is a series motor
The difference between the actual shaft speed and the rated synchronous speed
What is slip
Turnes the rotor in the same direction as the rotating field
What is torque
Contact surfaces mounted on the shaft of a motor or generator
What are slip rings
Type motor used in clocks
What is a single phase synchronous motor
Defines the starting torque characteristics
What is the NEMA design
Best type used where the load is variable, and speed variation is tolerable
What is compound
Is low under no load conditions
What is power factor
As much as 300% of motor full load current
What is motor inrush
Type of motor used where flammable dust or gas is present
What is squirrel cage
Type of motor typically used for small fans
What is a shaded pole motor
Indicated the amount of overload a motor can withstand
What is service factor
No torque is produced in this plane.
What is the neutral plane
An automatic limiter that reduces armature current.
What is CEMF
Rotor design most used for three phase motors
What is squirrel cage
The number of field poles must equal the number of stator poles
What is a synchronous motor
Rotor design when a motor requires frequent starts without overheating
What is a wound rotor
Two types of multi speed, squirrel cage induction motors
What are multiple winding and consequent pole
Describes the length of operation
What is duty