Motor Controls 3
Most DC motor contactors consist of ? set(s) of contacts.
1
What are the six steps used when troubleshooting a system
1) Define the problem 2) Decide what needs to be tested 3) Decide what type of test to perform 4) Correct the problem 5) Verify correct operation 6) Determine the cause of the failure
A single voltage DC motor has ? leads.
4
Control of the ? is used to control the speed and rotation.
Armature and Field voltage
The magnetic ? coil produces a magnetic field between the breaking contacts that forces the arc up, increasing the length of the arc and causing it to dissipate faster.
Blowout
A technology with all network devices connected to a central network media or cable identified as the backbone.
Bus
What type of flow meter depends upon the twist of the tube containing the flowing fluid to sense flow rate?
Coriolis
When analog control devices are located large distances from each other, which type of signal is preferable for installing the control wiring?
Current
Factors to not consider when installing a VFD
HP, speed, or torque
Which basic troubleshooting technique includes four levels of testing?
Information funneling
? are installed on power lines feeding VFDs to lessen the effects of harmonics generated by the VFDs.
Line reactors
Constant temperature and calorimetric sensors are types of ? flow sensors.
Mass
4 components to build a PLC-
Power Chasy Processor I/O mods
The ? limits armature current in a motor during starting and accelerating.
Rheostat Starter
A technology with all network devices connected to a network media or cable, which is connected in a loop.
Ring
A technology with all network devices connected to a common device called a hub or switch.
Star
Allen bradleys programming software includes RS Logic but not ?.
Step 7
A specification for an Ethernet® network calls for a 100BaseT system. What type of cable would be used for this network?
UTP (unshielded twisted pair)
What type of flow meter requires that particles must be present in the fluid being monitored to reflect signals back to the flow sensor?
Ultrasonic
A(n) ? flow sensor uses an object called a bluff body, which is placed in the fluid flow to produce whirlpools or eddies in the fluid flow stream.
Vortex
Motor control systems that control motor speed without feedback data for torque or speed are called ? control systems.
closed-loop
DC ? are used for analog signal control.
current and voltage
How do you troubleshoot a control valve?
induce 0-10v or 4-20ma signal into it
AC/DC, DC current-sinking, DC current-sourcing, and transistor-to-transistor logic (TTL) are the four most common types of ? circuits used in controller input modules.
input
Brushes on a DC motor should ?.
move freely
Controller input and output modules have ? between the field device power and the controller or motor drive system power to eliminate noise and operational problems.
opto-isolation
Braking resistor when using a dynamic breaking are ? with the armature.
parallel
Regenerative braking returns the regenerated power of a DC motor back to the ? .
power source
The architecture of the PC and PLC systems are similar with both featuring a motherboard, memory, expansion slots, and a(n) ? .
processor
DC drives use a ? method to smoothly accelerate and decelerate the motor.
ramping
A tachometer/generator produces a feedback voltage which is directly proportional to the ? of the motor.
speed
2 or more thermo couples.
thermopile
Speed and ? are two physical quantities that must be controlled in a motor drive.
torque
Power factor in synchronous motors have ?.
unity power factor
