True/False
Indicate whether the
statement is true or false.
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1.
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Synchronous motors are able to operate at the speed of the rotating magnetic
field because they are not induction motors.
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2.
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The amortisseur winding provides good starting torque and a relatively high
starting current.
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3.
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A synchronous motor should never be started with excitation applied to the
rotor.
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4.
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The excitation current should be connected to the rotor only after it has
accelerated to a speed that is close to synchronous speed.
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5.
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A synchronous motor can not be made to produce a leading power factor.
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Completion
Complete each
statement.
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6.
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Synchronous motors are sometimes operated without load to help correct plant
power factor. In this mode of operation, they are called ____________________.
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7.
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A special squirrel cage winding, called ____________________, is used to start a
synchronous motor.
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8.
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A switch called the ____________________ switch is used to connect the
excitation current to the motor.
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9.
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With a self-excited direct generator mounted on the rotor shaft, the amount of
excitation current is adjusted by controlling the ____________________ of the generator.
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10.
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The ____________________ relay is actually a timer that contains a current
operated coil instead of a voltage operated coil.
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Short Answer
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11.
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What is the function of the field discharge resistor?
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12.
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What is a brushless exciter?
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13.
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What is the polarized field frequency relay responsible for?
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14.
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What two conditions indicate that normal excitation has taken place?
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15.
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What happens when overexcitation takes place?
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