Unit 1
Alternator|A device that generates alternating current by means of conductors rotated in a magnetic field.
Armature|The rotating component of a generator.
Capacitor|An electrical storage device containing two metal plates separated b an insulating(dielectric) material.
Commutator|The movable contact surface on an electric generator or motor.
Dielectric|A material that strongly resists passage of current.
Effective voltage|See root-mean-square (rms) voltage.
Frequency|The number of complete cycles of an alternating current, sound wave, or vibrating object that occur in a period of time.
Fusible link|A circuit protective device that melts, opening the circuit, when the current is excessive.
Hertz(Hz)|The unit of measure for the frequency of alternating current. One Hertz equals one cycle per second.
Induction|To generate a current in a conductor by placing it in a moving magnetic field.
Induction motor|An AC motor.
Inertia|The tendency of a body in motion to remain in motion and a body at rest to remain at rest.
Isolation transformer|A transformer with a one-to-one turns ratio. It is used for personnel safety and to prevent electrical interference.
Megohmmeter(megger)|A test instrument used to test high-resistance circuits.
Microfarad|One-millionth of a farad. Used to rate capacitors.
Qualified person|One who has the skills and knowledge related to the construction and operation of electrical equipment and installations, and has received safety training to recognize and avoid the hazards involved.
Root-mean-square(rms) voltage|The value of AC voltage that will produce as much power when connected across a load as an equivalent amount of DC voltage. Also known as effective voltage.
Rotor|The rotating component of an induction motor.
Run capacitor|A capacitor that remains in the motor circuit while the motor is running to improve running efficiency.
Run winding|The stator winding of am otor that draws current during the entire running cycle of the motor.
Sinusoidal(sine) wave|The waveform created by an AC generator.
Start winding|The stator winding of a motor that is used to provide starting torque.
Stator|The stationary windings of a motor.
Synchronous speed|The maximum rated speed of a motor.
Torque|The force that must be generated to turn a motor.
Turns ratio|The ratio between the number of turns in the primary and secondary windings of a transformer.