A ? is a distortion in a voltage waveform where the voltage quickly drops toward zero and then
returns to the correct value. - ANSWER notch
The opposition to current flow that is only present in AC is ? . - ANSWER reactance
A ? is an inductor whose inductance is controlled through the use of a magnetic field created by
a second winding wound around the same iron core as the primary winding. - ANSWER
saturable-core ractor
Electric motors typically draw many times their full-load current during startup. - ANSWER True
a reactor should have about ? impedance to reduce notch depth by about 50% - ANSWER 3%
All two-winding transformers are isolation transformers - ANSWER True
? is a type of electromagnetic interference induced on power or communication lines - ANSWER
Common-mode noise
a ? is a reactor used to reduce common-mode noise current generated by the rapid switching of
a motor drive or a signaling device - ANSWER Common-mode choke
in a saturable- core reactor, large amounts of DC current can be controlled by a small amount of
AC current - ANSWER False
Zero-crossovers are often used for timing signals and to activate equipment - ANSWER True
, With a variable-frequency drive, unwanted pulses of current are caused by fast-changing
voltages from the drive - ANSWER True
With 3-phase motor drives that use SCR 6-pulse (6-diode)rectifiers, only one SCR can be on at
any given time - ANSWER False
A ? reduction in notch depth is enough to eliminate extra zero crossovers that cause problems -
ANSWER 50%
Note: Higher impedance may cause problems with sensitive equipment because the wider
notch may be seen as a loss of voltage. Lower impedance may not reduce the notch depth
enough to eliminate problems.
A saturable- Core reactor consists of one winding - ANSWER False
Electrostatic shield can prevent common-mode noise from transferring from the transformers
primary to the secondary only if the secondary is grounded - ANSWER False
? help eliminate voltage spikes by slowing down the rate of change in the drive out put voltage -
ANSWER output reactors
to reduce notching a reactor can be used to add impedance. the added impedance.
Increases or decreases Notch
widens or narrows Width - ANSWER decreases notch depth and widens notch width
Which of the following is not a basic function of a drive isolation transformer?
a. Common-mode noise reduction
returns to the correct value. - ANSWER notch
The opposition to current flow that is only present in AC is ? . - ANSWER reactance
A ? is an inductor whose inductance is controlled through the use of a magnetic field created by
a second winding wound around the same iron core as the primary winding. - ANSWER
saturable-core ractor
Electric motors typically draw many times their full-load current during startup. - ANSWER True
a reactor should have about ? impedance to reduce notch depth by about 50% - ANSWER 3%
All two-winding transformers are isolation transformers - ANSWER True
? is a type of electromagnetic interference induced on power or communication lines - ANSWER
Common-mode noise
a ? is a reactor used to reduce common-mode noise current generated by the rapid switching of
a motor drive or a signaling device - ANSWER Common-mode choke
in a saturable- core reactor, large amounts of DC current can be controlled by a small amount of
AC current - ANSWER False
Zero-crossovers are often used for timing signals and to activate equipment - ANSWER True
, With a variable-frequency drive, unwanted pulses of current are caused by fast-changing
voltages from the drive - ANSWER True
With 3-phase motor drives that use SCR 6-pulse (6-diode)rectifiers, only one SCR can be on at
any given time - ANSWER False
A ? reduction in notch depth is enough to eliminate extra zero crossovers that cause problems -
ANSWER 50%
Note: Higher impedance may cause problems with sensitive equipment because the wider
notch may be seen as a loss of voltage. Lower impedance may not reduce the notch depth
enough to eliminate problems.
A saturable- Core reactor consists of one winding - ANSWER False
Electrostatic shield can prevent common-mode noise from transferring from the transformers
primary to the secondary only if the secondary is grounded - ANSWER False
? help eliminate voltage spikes by slowing down the rate of change in the drive out put voltage -
ANSWER output reactors
to reduce notching a reactor can be used to add impedance. the added impedance.
Increases or decreases Notch
widens or narrows Width - ANSWER decreases notch depth and widens notch width
Which of the following is not a basic function of a drive isolation transformer?
a. Common-mode noise reduction
