Download Short-Term Incumbent Worker Training Module Course - e

Curriculum Outline
Module Title: DC Drives and DC Motor Control
Module Number:
Length: 16 Contact Hours
Credit Hours: 1 Credit Hour
Module Description: This course provides the fundamental skills in DC motor
controllers for entry-level electrical maintenance personnel. Prerequisite training
for this course is completion of an AC/DC course, or equivalent training.
Goal of Training: Skills from this training assist in the installation, configuration,
and troubleshooting of DC motor controllers which will reduce unplanned
machinery down time, improve production efficiency, and enhance employee job
satisfaction and employee value to the production process.
Reference Material: Each participant receives Allen-Bradley Bulletin 1365 DC
Drive User Manual.
Module Elements (list of topics or segments):
1)
2)
3)
4)
5)
6)
7)
8)
Magnetism
Motor mechanical parameters
Motor electrical parameters
DC motor design and operation
Rectifiers and inverters
DC drives
Typical DC drive construction
Parameters programmed into DC drives
Course Objectives: At the completion of this course, the participant will be able
to…
1) Understand magnetism
a) Magnetic variables - magnetomotive force, flux, reluctance,
permeability
b) Magnetic poles
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c) Inductance
d) Transformers
e) Motors
2)
Understand motor mechanical parameters
a) Torque
b) Speed
c) Shaft design
d) Frame size
e) Bearings and friction
f) Temperature ratings/insulation class
3)
Understand motor electrical parameters
a) Service voltage/motor voltage
b) Full load amps
c) Horsepower/kilowatts
d) Phase (AC only)
e) Frequency (AC only)
f) Locked rotor current
g) Service factor
4)
Understand the design of DC motors
a) Brush motors and commutators
b) Brushless motors
5)
Understand the operation of DC motors
a) Commutation
b) Switching with brushless DC motors
6)
Understand the creation of DC power
a) Rectifiers
b) Inverters
7)
Understand DC drives
a) Creating different DC voltage levels
b) Current and power consumption
c) Overload protection
d) Short circuit protection
8)
Understand typical DC drive construction
a) Earlier relay control
b) Connection to motor
c) Power supply and circuit protection
d) Power switching
e) Display and data entry
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9)
Understand typical operating parameters used in DC drives
a) Start/stop/jog/reverse
b) Output voltage
c) Output speed
d) Status/fault indication
Session 1
Length: 4 Hours
Recommended Schedule:
Segments:
1)
2)
3)
Magnetism
Motor mechanical parameters
Motor electrical parameters
Assignments and Activity Notes:
Lecture topics:
 Magnetism
 Flux, flux density, reluctance, permeability, magnetomotive force
 Magnetic poles
 Inductance, self- and mutual Inductors
 Transformers
 Electrical-magnetic analogies
 Magnetic forces in motors
 Motor mechanical parameters
 Torque
 Speed
 Shaft design, keys, keyways
 Frame size, dimensions, mounting configuration
 Friction, bearings, lubrication
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 Temperature ratings, insulation class
 Effects of heat and friction on motor
 Motor electrical parameters
 Service voltage, motor voltage, resistance in leads
 Full load amps
 Horsepower, kilowatts
 DC, 3-phase AC, 1-phase AC power
 Frequency (AC, DC=0 frequency)
 Locked rotor current
 Service factor
 Determining the size motor needed for an application
Discussion: Ask participants for their name and background, if they work in
industry, if their facility uses any DC motors that they know of, and how those DC
motors are employed.
Demonstrations:
 Show the participants examples of DC motors
 Identify the various components of the DC motor
Activities

Give participants a multiple choice quiz (25 questions); provide a
prize (e.g., Radio Shack gift certificate) to the highest scoring
participant.
Instructor Remarks: Supplemental activities should involve the student’s
retention of information. Quiz the students by putting some symbols on the
dry erase board or chalkboard and have them identify them. This can also be
done in reverse by providing the name of the fitting and having the students
draw the appropriate symbol. Criticism should reinforce the student’s learning
and encourage them to correct any wrong answers. Instructors may also
provide a print that requires students to identify components, or take a
pictorial and draw a sketched print using appropriate symbols.
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Session 2
Length: 4 Hours
Recommended Schedule:
Segments:
4) DC motor design and operation
Assignments and Activity Notes:
Lecture topics:
 DC motor design
 Brush DC motors - series, shunt, compound
 Brushless DC motors
 DC motor operation
 Commutation
 Switching for brushless DC motors
Discussion: Lab and demonstration results
Demonstrations:
 Show the connection and operation of a brush DC motor
 Show a simple control circuit and operation of a brushless DC motor
Activities

Have participants connect voltmeters and ammeters to DC motors,
and compute the power drawn for various loads.
Instructor Remarks: This session is to reinforce the concepts learned in the first
session and provide the students with more hands-on activities related to the
components used in the field. As the session is heavy in hands-on activities, it is
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a good practice to keep a close eye on the students at all times to ensure a high
quality of work.
Session 3
Length: 4 Hours
Recommended Schedule:
Segments:
5) Rectifiers and Inverters
6) DC Drives
7) Typical DC Drive Construction
Assignments and Activity Notes:
Lecture Topics:
 Rectifiers and inverters
 The structure of DC waveforms
 The structure of DC
 The rectification process
 Circuits used as rectifiers
 The invertion process
 Circuits used as inverters
 DC drives
 Creating different DC voltage levels
 Current and power consumption of the DC drive
 Overload protection
 Short circuit protection
 Typical DC drive construction
 Earlier relay control
 Connection to motor
 Power supply and circuit protection
 Power switching
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 Display and data entry
Discussion: Lab and demonstration results
Demonstrations:
 Show participants a properly connected DC drive and motor
Activities
 Have participants connect a DC motor to a DC drive. Review their work.
Have them attempt to start the motor. Show them the minimum
parameters needed to get the motor running.
Instructor Remarks: Demonstrations should emphasize not only safe tool use,
but also proper tool selection. Exercises are sequenced to build off of previous
activities and build awareness of the intricacies of the trade. By the end of this
session, students should have a fundamental knowledge of the equipment as
well as some practical knowledge of solving some basic drive or motor problems.
Session 4
Length: 4 Hours
Recommended Schedule:
Segments:
8) Parameters programmed into DC drives
Assignments and Activity Notes:
Lecture topics:
 Parameters programmed into DC drives
 Start-stop-jog-reverse
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 Output voltage
 Output speed
 Status, fault indication
Discussion: Lab and demonstration results
Demonstrations: Show participants a properly connected Inverter DC drive and
motor
Activities
 Have participants modify various parameters for the drive and log the
results. Present the participants with a problem and see if they are able
to correctly modify the parameters to get the desired result. Connect the
DC motor to a convyor system (or similar) and have students control
operation of the system.
Instructor Remarks: Demonstrations should emphasize not only safe tool use,
but also proper tool selection. Exercises are sequenced to build off of previous
activities and build awareness of the intricacies of the trade. By the end of this
session, students should have a fundamental knowledge of the equipment as
well as some practical knowledge of solving some basic drive or motor problems.
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Module Instructional Resources
Supplemental Materials (texts manuals, booklets, handouts): Reference
Material: Each participant receives Allen-Bradley Bulletin 1365 DC Drive User
Manual, published by Rockwell Automation.
Hardware/Software:
Websites:
 Allen Bradley Company http://www.ab.com
 Baldor Co. http://www.baldor.com
 Square D Co. http://www.squared.com
Consumable materials and supplies: 14 AWG wire, electrical tape, and a
variety of terminal connectors.
Other: Graph paper
Evaluation/Assessment and Grading
Written Assessment: Trainees must correctly describe DC drive control
systems with at least 75% accuracy. Practical application must be built to an
acceptable standard including level, accurately measured, supported, functional
without leaks. Also, all hands-on challenges must be performed independently.
Attendance: All trainees missing any training events must notify the instructor in
advance to be considered for make-up activities. In order to pass, trainees must
not miss more than 4 hours of instruction. Make-up time may be offered to the
trainee, according to the excused absence policy.
Participation: Trainees must demonstrate their abilities to independently
perform selected hands-on activities. Many hands-on training events are
performed in pairs and everyone is expected to be a productive team member.
This product was funded by a grant awarded under the President’s High Growth Job Training Initiative as implemented by the U.S. Department of Labor’s
Employment & Training Administration. The information contained in this product was created by a grantee organization and does not necessarily reflect the
official position of the U.S. Department of Labor. All references to non-governmental companies or organizations, their services, products, or resources are offered
for informational purposes and should not be construed as an endorsement by the Department of Labor. This product is copyrighted by the institution that created
it and is intended for individual organizational, non-commercial use only.
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