Chapter 10 elec
In a three phase AC generator each of the three generated voltages is how many degrees apart from each other
120 degrees
In a two field pole single phase AC generator how many mechanical degrees of rotation does the armature have to rotate to produce one complete AC sine wave.
360 degrees
AC generators
Also referred to as alternators, convert mechanical energy into AC voltage and current.
surge suppressor
An electrical device that provides protection from transient voltages by limiting the level of voltage allowed downstream from the surge suppressor
What is the rotating coil of a generator called?
Armature
Delta Connection
Connection that has each coil end connected end to end to form a closed loop
Wye (Y) connection
Connection that has one end of each coil connected together and the other end of each coil left open for external connection.
temporary power interruption
Decrease to 0 V on one or more powerlines lasting for more than three seconds up to one minute
Momentary power interruption
Decreased to 0 V on one or more powerlines blessing from 0.5 cycles up to three seconds
And what type of connection are there to phase 2 neutral legs with the same voltage in a third phase to neutral leg that should not be used
Delta
And what type of generator are the 3 windings connected end to end to form a closed loop
Delta
For long term power interruption protection, a generator/UPS is used.
For short term power interruption, a static UPS is used.
Are slip rings used to convert generated AC voltage to DC voltage?
No
Open circuit transition switching
Process in which power is momentarily disconnected when switching a circuit from one voltage supply to another
three phase generator
Provides a more consistent voltage than single phase generator
Line-to-line Voltage/ Line voltage
The voltage measured between the lines
And what type of connection is the voltage between anyone of the three phases and the neutral the same
Wye
And what type of generator are the end of each of the three coil windings connected together
Wye connection
What is another name for an AC generator?
alternator
Slip rings
are metallic rings connected to the ends of an armature and are used to connect the induced voltage to the brushes
What produces the stationary magnetic field of a generator?
field windings
Each complete rotation of the armature in a single phase one wire AC generator produces one complete alternating current cycle.
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However, most generators use electromagnets, which must be supplied with current.
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None of the three wires are normally connected to ground
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The output of a 3 phase AC generator results in three output voltages 120 degrees out of phase with each other.
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The three ends can be safely connected at the neutral point because no voltage difference exists between them.
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Voltage between any two lines in a wye-connected AC generator is 1.73 multiplied by any of the individual phase voltages. If the 1 phase voltage is 100v, then the voltage between any two lines in the wye configuration will be 173 V (100x1.73)
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Brush
Sliding contact that rises against the commutator segments or slip rings and is used to connect the armature to the external circuit