Chapter 9 and 10
Today, with many components derated to save energy and operating cost, the range is normally?
5% to -10%
The high current shirt can turn into an ?
Arc Blast
Sustained power interruption are commonly results of ?
Blow fuses, or damaged equipment
____ connection that has each coil end connected end to end to form a closed loop?
Delta
What is a arc blast?
Explosion that occurs when the surrounding air becomes ionized and conductive.
Shunt-Wound generator has?
Field Windings connected in parallel ( shunt ) with the armature and the external circuit ( load )
Series-Wound Generator has its?
Field Windings connected in series with the armature and the external circuit( load )
What does a DC generator consist of ?
Field windings, Armature, Commutator, Brushes
The commutator segments reverse the connections to the brushes every ____?
Half-Cycle
Middle Finger points?
Induced Current
Uninterruptible power system is a power supply that provides constant on-line power when the primary power supply is ?
Interrupted
Dc power can be converted into AC using an ?
Inverter
_________ is the relationship between the current in a conductor and the magnetic field?
Left-Hand
Phase to Phase voltage is also referred as ?
Line Voltage
Voltage measured between the lines are known as ?
Line to Line voltage
What is generator?
Machine that converts mechanical enegry into electrical enegry by means of electromagnetic induction
Field Windings are electromagnets used to produce?
Magnetic Field
Index Finger points?
Magnetic Field
Permanent magnets are used in very small machines referred to as ?
Magnetos
In AC Slip Rings are________ connected to the ends of the armature and are used to connect the induced voltage to the brushes?
Metallic Rings
Thumb Points ?
Motion of the conductor
Armature is a _______ of wire in a generator that rotates through the magnetic field?
Movable Coil
Three ends can be safely connected at the ________point because, no voltage difference exists between them?
Neutral
Open circuit transition switching is a process in which _____ is momentarily disconnected when switching a circuit from one voltage supply to another?
Power
Output voltage of a series-wound generator may be controlled by?
Rheostat
Output voltage of a shunt-wound generator may be controlled by?
Rheostat
Pulsations in output voltage reduces ?
Ripples
If the generator itself supplies current for the field windings, the generator is referred to as _______ ?
Self-Excited
Compound-Wound is a generator that is connected in?
Series and Parallel
Three types of DC Generators are?
Series-Wound, Shunt-Wound, and Compound-Wound Generators
Transient voltage typically exist for very ____?
Short time
___________are two types of AC Generators?
Single & Three Phase
Three-Phase has ______ leads coming from the armature coils?
Six
AC generators uses _______ to connect the armature to the external circuit ( load ) ?
Slip Rings
Dc Generator dont have _____ but, AC have _____?
Slip Rings
Brushes are made of ?
Soft Carbon
_____ is a electrical device that provides protection from transient voltages by limiting the level of voltage allowed downstream from the surge suppressor?
Surge suppressor
Three-Phase generators have __________ armatures?
Three
Delta connected system permits different voltage.
True
_____ is used to show magnitude and direction. Also is another way to look at output voltage of a AC generator?
Vector
______ connection is a connection that has one end of each coil connected together and the other end of each coil?
Wye
AC generator doesnt have a ?
Commutator
AC power can be converted into DC using?
Converter
Voltage range is used because overvoltage is generally more damaging than?
Undervoltage
Strength of the voltage induced in one side of an _____ is always the same strength?
Armature
________Sliding contact that rides against the commutator segments or slip rings?
Brushes
____ is also referred as a voltage spike, is temporary, unwanted voltage in an electrical circuit?
Transient Voltage
Momentary power interruption can be caused when lighting strikes nearby.
True
Rated voltage is a voltage range that was normally 10%.
True
Total voltage of a full rotation of an armature is ______ the voltage of each coil half?
Twice
Three-Phase generators provide a more consistent _______ than single-phase Generators?
Voltage
In a single-phase AC generator the armature begins to rotate in clockwise direction there is no _____ and no ________ in the external (load) circuit because the armature is nit cutting across any magnetic lines of force (0° of rotation)
Voltage & Current
Three-Phase generators are either ___?
Wye or Delta connections
DC generators operate on the principle that when a coil of wire is rotated in a magnetic field, ______ is induced in the coil?
A voltage
Delta connected system has current flow of ______ ?
10A
_______ Ring made of segments that are insulated from one another?
Commutator
Three-Phase have three equally spaced armature windings _______ out of phase with each other?
120°
Automatic circuit breaker normally takes from ____ cycles to about 5 sec to close?
20
Magnetic Field used in a generator can be produced by ?
Permanent Magnets or Electromagnets
Voltage measured across a single winding or phase is known as a the?
Phase voltage
Series-Wound generators have ?
Poor voltage regulation
Momentary power interruption is decreased to ____ V on one or more power lines lasting from 0.5 cycles up to 3 sec?
0
Sustained power interruption is a decrease to 0v on all power lines for a period of more than ___ min?
1
Temporary power interruption is a decrease to 0v on one or more power lines lasting for more than 3 sec up to ____ min?
1
In a delta connected system back to the connection point shows that the _____ current supplied to the line is supplied by two coils?
Current
______ in the external circuit always flow in one direction?
Current
In delta connected systems, the voltage measured across any two lines is ________ to the voltage generated in the coil Winding?
Equal
Single-Phase generators have ________ armature?
One
AC generators are designed to produce a rated ?
Output Voltage