Chapter 10 & 26 Flashcards
The voltage drop when an AC motor drive is measured to have 230V with no load and 226V under full load is ________ V.
4
When using a motor drive to control a motor, the drive is wired following the __________ wiring diagram provided by the drive manufacturer.
control-circuit
Some drives may include built-in PLC/PLR functions such as internal timers and ____________ .
counters
Display parameters normally include ___________ .
Drive output frequency
motor current draw
drive output voltage
Common motor drive faults include ___________ .
power loss
DC motor drives include _________ and/or regenerative braking.
dynamic
Current to an AC motor drive is limited by the size of the conductors to the drive, _________, and transformer(s) delivering power to the system.
fuse and circuit beaker sizes
The voltage drop percentage when an AC motor drive has a 4V drop with a 230V no-load measurement is __________ %.
- 739%
1. 7
The control voltage of a motor drive is normally __________ VDC or 24 VDC.
12
__________ motor drives are available for connection to DC or AC power supplies.
DC
__________ is a method of controlling the amount of voltage sent to a motor.
Pulse width modulation (PWM)
AC motors should not be driven at speeds greater than __________ % above their rated nameplate speed.
10
In industrial system, standard control-circuit power is supplied at 0V to __________ V.
10
__________ parameters are normally the most conservative and frequently used parameter values that create the least amount of risk to equipment and personnel.
Default
The two major methods of braking a DC motor faster tan by coasting are dynamic braking and __________ braking.
regenerative
The three main sections of AC motor drives are converter, DC bus, and ____________ .
inverter
Capacitors and __________ in a DC bus filter and maintain proper voltage level.
inductors
__________ is the frequency that controls the number of times solid-state switches in an inverter of a pulse width modulation motor drive turn ON and OFF.
The carrier frequency
The speed of a AC motor is determined by the number of __________ and frequency of the AC power supply.
stator poles
A magnetic motor starter can turn a motor __________ and OFF, but cannot set the acceleration and deceleration times for the motor.
ON
The cost of a motor drive for any given horsepower ___________ with drives that offer advanced features.
increases
__________ work well in applications that require basic ON and OFF motor control.
magnetic motor starter
As the length of conductors increases and/or the motor drive output carrier frequency increases, voltage spikes __________ .
increases
When voltage spikes become a problem, motor lead length should be ___________ and/or filters that suppress voltage spikes should be added.
reduced
A(n) __________ is an electronic unit designed to control the speed of a motor using solid-state components.
motor drive
The energy produced from a DC motor when it acts as a DC generator is called __________ .
counter electromotive force (CEMF)
__________ is a method of motor braking in which the regenerated power of a DC motor that is coming to a stop is returned to the input power supply.
Regenerative braking
Controlling the ___________ ratio applied to an AC motor controls motor torque.
volts-per-hertz
When pulse width modulation is used with AC voltage, __________ insulated-gate bipolar transistors are used for each phase.
two
To prevent damage to diodes in a converter and to AC motor drive electronic circuits, protection against ___________ must be included in the drive.
transient voltages
