The document discusses electric motor problems in three paragraphs. It begins with an overview of electric motor construction and operation, describing how alternating current in the stator coils creates a magnetic field that induces current in the rotor bars and causes the rotor to spin. It then explains twelve common problems with electric motors like water or dust ingress causing shorts, overheating from undersizing or load changes, bearing failure, and issues with mounting, alignment, or housing type. The final paragraph discusses characteristics of electric motors and how the torque and electrical currents vary with rotor speed and load.
Kioti Daedong CK25 Tractor Service Repair Manualjksemmd ekdmmd
This is the Highly Detailed factory service repair manual for theKIOTI DAEDONG CK25 TRACTOR, this Service Manual has detailed illustrations as well as step by step instructions,It is 100 percents complete and intact. they are specifically written for the do-it-yourself-er as well as the experienced mechanic.KIOTI DAEDONG CK25 TRACTOR Service Repair Workshop Manual provides step-by-step instructions based on the complete dis-assembly of the machine. It is this level of detail, along with hundreds of photos and illustrations, that guide the reader through each service and repair procedure. Complete download comes in pdf format which can work under all PC based windows operating system and Mac also, All pages are printable. Using this repair manual is an inexpensive way to keep your vehicle working properly.
Service Repair Manual Covers:
Chapter 0 Safety First
Chapter 1 General
Chapter 2 Engine
Chapter 3 Clutch
Chapter 4 Transmission
Chapter 5 HST
Chapter 6 Rear Axle
Chapter 7 Brake
Chapter 8 Front Axle
Chapter 9 Steering System
Chapter 10 Hydraulic System
Chapter 11 Electric System
Chapter 12 Index
File Format: PDF
Compatible: All Versions of Windows & Mac
Language: English
Requirements: Adobe PDF Reader
NO waiting, Buy from responsible seller and get INSTANT DOWNLOAD, Without wasting your hard-owned money on uncertainty or surprise! All pages are is great to haveKIOTI DAEDONG CK25 TRACTOR Service Repair Workshop Manual.
Looking for some other Service Repair Manual,please check:
https://www.aservicemanualpdf.com/
Thanks for visiting!
8
Kioti Daedong CK25 Tractor Service Repair Manualjksemmd ekdmmd
This is the Highly Detailed factory service repair manual for theKIOTI DAEDONG CK25 TRACTOR, this Service Manual has detailed illustrations as well as step by step instructions,It is 100 percents complete and intact. they are specifically written for the do-it-yourself-er as well as the experienced mechanic.KIOTI DAEDONG CK25 TRACTOR Service Repair Workshop Manual provides step-by-step instructions based on the complete dis-assembly of the machine. It is this level of detail, along with hundreds of photos and illustrations, that guide the reader through each service and repair procedure. Complete download comes in pdf format which can work under all PC based windows operating system and Mac also, All pages are printable. Using this repair manual is an inexpensive way to keep your vehicle working properly.
Service Repair Manual Covers:
Chapter 0 Safety First
Chapter 1 General
Chapter 2 Engine
Chapter 3 Clutch
Chapter 4 Transmission
Chapter 5 HST
Chapter 6 Rear Axle
Chapter 7 Brake
Chapter 8 Front Axle
Chapter 9 Steering System
Chapter 10 Hydraulic System
Chapter 11 Electric System
Chapter 12 Index
File Format: PDF
Compatible: All Versions of Windows & Mac
Language: English
Requirements: Adobe PDF Reader
NO waiting, Buy from responsible seller and get INSTANT DOWNLOAD, Without wasting your hard-owned money on uncertainty or surprise! All pages are is great to haveKIOTI DAEDONG CK25 TRACTOR Service Repair Workshop Manual.
Looking for some other Service Repair Manual,please check:
https://www.aservicemanualpdf.com/
Thanks for visiting!
8
Kioti Daedong DK35 Tractor Service Repair Manualhjnnsemmm
This is the Highly Detailed factory service repair manual for theKIOTI DAEDONG DK35 TRACTOR , this Service Manual has detailed illustrations as well as step by step instructions,It is 100 percents complete and intact. they are specifically written for the do-it-yourself-er as well as the experienced mechanic.KIOTI DAEDONG DK35 TRACTOR Service Repair Workshop Manual provides step-by-step instructions based on the complete dis-assembly of the machine. It is this level of detail, along with hundreds of photos and illustrations, that guide the reader through each service and repair procedure. Complete download comes in pdf format which can work under all PC based windows operating system and Mac also, All pages are printable. Using this repair manual is an inexpensive way to keep your vehicle working properly.
Service Repair Manual Covers:
Chapter 1 general information
1. tractor view
2. tightening torque for standard bolts and nuts
3. specifications
4. identification
5. caution before repair
6. regular check
7. oil & water supply list
Chapter 2 engine system
1. general
2. structure and function
3. disassembling and servicing
Chapter 3 main body
1. exterior
2. clutch
3. transmission
4. rear axle
5. brake
6. front axle
7. steering system
8. hydraulic system
Chapter 4 electric system
1. electronic instrumentation
2. switches
3. lamps
4. fuse box and relay
5. motors
6. battery
7. wiring diagram
8. trouble shooting
File Format: PDF
Compatible: All Versions of Windows & Mac
Language: English
Requirements: Adobe PDF Reader
NO waiting, Buy from responsible seller and get INSTANT DOWNLOAD, Without wasting your hard-owned money on uncertainty or surprise! All pages are is great to haveKIOTI DAEDONG DK35 TRACTOR Service Repair Workshop Manual.
Looking for some other Service Repair Manual,please check:
https://www.aservicemanualpdf.com/
Thanks for visiting!
8
2002 Arctic Cat Z 440 SNOWMOBILE Service Repair Manualfudjjskekmd
This is the Highly Detailed factory service repair manual for the2002 ARCTIC CAT Z 440 SNOWMOBILE, this Service Manual has detailed illustrations as well as step by step instructions,It is 100 percents complete and intact. they are specifically written for the do-it-yourself-er as well as the experienced mechanic.2002 ARCTIC CAT Z 440 SNOWMOBILE Service Repair Workshop Manual provides step-by-step instructions based on the complete dis-assembly of the machine. It is this level of detail, along with hundreds of photos and illustrations, that guide the reader through each service and repair procedure. Complete download comes in pdf format which can work under all PC based windows operating system and Mac also, All pages are printable. Using this repair manual is an inexpensive way to keep your vehicle working properly.
Service Repair Manual Covers:
General Information
Engine
Engine-Related Items
Fuel Systems
Engine Electrical Systems
Chassis Electrical Systems
Steering and Body
Drive Train and Brake Systems
Track / Rear Suspension
Wiring Diagrams
File Format: PDF
Compatible: All Versions of Windows & Mac
Language: English
Requirements: Adobe PDF Reader
NO waiting, Buy from responsible seller and get INSTANT DOWNLOAD, Without wasting your hard-owned money on uncertainty or surprise! All pages are is great to have2002 ARCTIC CAT Z 440 SNOWMOBILE Service Repair Workshop Manual.
Looking for some other Service Repair Manual,please check:
https://www.aservicemanualpdf.com/
Thanks for visiting!
2011 Yamaha 6×6 Type C COMMAND LINK PLUS Service Repair Manual SN:1001104 and upjhsendm
This is the Highly Detailed factory service repair manual for the2011 YAMAHA 6×6 TYPE C COMMAND LINK PLUS, this Service Manual has detailed illustrations as well as step by step instructions,It is 100 percents complete and intact. they are specifically written for the do-it-yourself-er as well as the experienced mechanic.2011 YAMAHA 6×6 TYPE C COMMAND LINK PLUS Service Repair Workshop Manual provides step-by-step instructions based on the complete dis-assembly of the machine. It is this level of detail, along with hundreds of photos and illustrations, that guide the reader through each service and repair procedure. Complete download comes in pdf format which can work under all PC based windows operating system and Mac also, All pages are printable. Using this repair manual is an inexpensive way to keep your vehicle working properly.
Service Repair Manual Covers:
General Information
Specifications
Technical Feature and Description
Rigging Information
Troubleshooting
Electrical System
Digital Electrical Control Unit
Index
Appendix
File Format: PDF
Compatible: All Versions of Windows & Mac
Language: English
Requirements: Adobe PDF Reader
NO waiting, Buy from responsible seller and get INSTANT DOWNLOAD, Without wasting your hard-owned money on uncertainty or surprise! All pages are is great to have2011 YAMAHA 6×6 TYPE C COMMAND LINK PLUS Service Repair Workshop Manual.
Looking for some other Service Repair Manual,please check:
https://www.aservicemanualpdf.com/
Thanks for visiting!
Kioti Daedong DK35 Tractor Service Repair Manualhjnnsemmm
This is the Highly Detailed factory service repair manual for theKIOTI DAEDONG DK35 TRACTOR , this Service Manual has detailed illustrations as well as step by step instructions,It is 100 percents complete and intact. they are specifically written for the do-it-yourself-er as well as the experienced mechanic.KIOTI DAEDONG DK35 TRACTOR Service Repair Workshop Manual provides step-by-step instructions based on the complete dis-assembly of the machine. It is this level of detail, along with hundreds of photos and illustrations, that guide the reader through each service and repair procedure. Complete download comes in pdf format which can work under all PC based windows operating system and Mac also, All pages are printable. Using this repair manual is an inexpensive way to keep your vehicle working properly.
Service Repair Manual Covers:
Chapter 1 general information
1. tractor view
2. tightening torque for standard bolts and nuts
3. specifications
4. identification
5. caution before repair
6. regular check
7. oil & water supply list
Chapter 2 engine system
1. general
2. structure and function
3. disassembling and servicing
Chapter 3 main body
1. exterior
2. clutch
3. transmission
4. rear axle
5. brake
6. front axle
7. steering system
8. hydraulic system
Chapter 4 electric system
1. electronic instrumentation
2. switches
3. lamps
4. fuse box and relay
5. motors
6. battery
7. wiring diagram
8. trouble shooting
File Format: PDF
Compatible: All Versions of Windows & Mac
Language: English
Requirements: Adobe PDF Reader
NO waiting, Buy from responsible seller and get INSTANT DOWNLOAD, Without wasting your hard-owned money on uncertainty or surprise! All pages are is great to haveKIOTI DAEDONG DK35 TRACTOR Service Repair Workshop Manual.
Looking for some other Service Repair Manual,please check:
https://www.aservicemanualpdf.com/
Thanks for visiting!
8
2002 Arctic Cat Z 440 SNOWMOBILE Service Repair Manualfudjjskekmd
This is the Highly Detailed factory service repair manual for the2002 ARCTIC CAT Z 440 SNOWMOBILE, this Service Manual has detailed illustrations as well as step by step instructions,It is 100 percents complete and intact. they are specifically written for the do-it-yourself-er as well as the experienced mechanic.2002 ARCTIC CAT Z 440 SNOWMOBILE Service Repair Workshop Manual provides step-by-step instructions based on the complete dis-assembly of the machine. It is this level of detail, along with hundreds of photos and illustrations, that guide the reader through each service and repair procedure. Complete download comes in pdf format which can work under all PC based windows operating system and Mac also, All pages are printable. Using this repair manual is an inexpensive way to keep your vehicle working properly.
Service Repair Manual Covers:
General Information
Engine
Engine-Related Items
Fuel Systems
Engine Electrical Systems
Chassis Electrical Systems
Steering and Body
Drive Train and Brake Systems
Track / Rear Suspension
Wiring Diagrams
File Format: PDF
Compatible: All Versions of Windows & Mac
Language: English
Requirements: Adobe PDF Reader
NO waiting, Buy from responsible seller and get INSTANT DOWNLOAD, Without wasting your hard-owned money on uncertainty or surprise! All pages are is great to have2002 ARCTIC CAT Z 440 SNOWMOBILE Service Repair Workshop Manual.
Looking for some other Service Repair Manual,please check:
https://www.aservicemanualpdf.com/
Thanks for visiting!
2011 Yamaha 6×6 Type C COMMAND LINK PLUS Service Repair Manual SN:1001104 and upjhsendm
This is the Highly Detailed factory service repair manual for the2011 YAMAHA 6×6 TYPE C COMMAND LINK PLUS, this Service Manual has detailed illustrations as well as step by step instructions,It is 100 percents complete and intact. they are specifically written for the do-it-yourself-er as well as the experienced mechanic.2011 YAMAHA 6×6 TYPE C COMMAND LINK PLUS Service Repair Workshop Manual provides step-by-step instructions based on the complete dis-assembly of the machine. It is this level of detail, along with hundreds of photos and illustrations, that guide the reader through each service and repair procedure. Complete download comes in pdf format which can work under all PC based windows operating system and Mac also, All pages are printable. Using this repair manual is an inexpensive way to keep your vehicle working properly.
Service Repair Manual Covers:
General Information
Specifications
Technical Feature and Description
Rigging Information
Troubleshooting
Electrical System
Digital Electrical Control Unit
Index
Appendix
File Format: PDF
Compatible: All Versions of Windows & Mac
Language: English
Requirements: Adobe PDF Reader
NO waiting, Buy from responsible seller and get INSTANT DOWNLOAD, Without wasting your hard-owned money on uncertainty or surprise! All pages are is great to have2011 YAMAHA 6×6 TYPE C COMMAND LINK PLUS Service Repair Workshop Manual.
Looking for some other Service Repair Manual,please check:
https://www.aservicemanualpdf.com/
Thanks for visiting!
SlideShare now has a player specifically designed for infographics. Upload your infographics now and see them take off! Need advice on creating infographics? This presentation includes tips for producing stand-out infographics. Read more about the new SlideShare infographics player here: http://wp.me/p24NNG-2ay
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No need to wonder how the best on SlideShare do it. The Masters of SlideShare provides storytelling, design, customization and promotion tips from 13 experts of the form. Learn what it takes to master this type of content marketing yourself.
10 Ways to Win at SlideShare SEO & Presentation OptimizationOneupweb
Thank you, SlideShare, for teaching us that PowerPoint presentations don't have to be a total bore. But in order to tap SlideShare's 60 million global users, you must optimize. Here are 10 quick tips to make your next presentation highly engaging, shareable and well worth the effort.
For more content marketing tips: http://www.oneupweb.com/blog/
Are you new to SlideShare? Are you looking to fine tune your channel plan? Are you using SlideShare but are looking for ways to enhance what you're doing? How can you use SlideShare for content marketing tactics such as lead generation, calls-to-action to other pieces of your content, or thought leadership? Read more from the CMI team in their latest SlideShare presentation on SlideShare.
Each month, join us as we highlight and discuss hot topics ranging from the future of higher education to wearable technology, best productivity hacks and secrets to hiring top talent. Upload your SlideShares, and share your expertise with the world!
Not sure what to share on SlideShare?
SlideShares that inform, inspire and educate attract the most views. Beyond that, ideas for what you can upload are limitless. We’ve selected a few popular examples to get your creative juices flowing.
How to Make Awesome SlideShares: Tips & TricksSlideShare
Turbocharge your online presence with SlideShare. We provide the best tips and tricks for succeeding on SlideShare. Get ideas for what to upload, tips for designing your deck and more.
Dimensional and Constructional Details of Components, Fundamentals of TNM Met...IJERA Editor
For the improvement in thermal design of squirrel cage induction (SCIM) motor, it is essential to know details
of the methods for evaluation of thermal distribution in a SCIM motor. A presentation of various details of
methods of basics of heat transfer that occur in a SCIM motor is done in this report. SCIM motors have wide
applications and thus their construction is completely influenced by the starting characteristics specified by the
operating loads. General constraints of a motor and specification of 30 KW motor are presented in this report as
a case study of constraints. As the next step the Thermal Network Method (TNM) has been explained.
Gear pump operation & maintenance.
REF: https://bin95.com/vocational-training/maintenance/reliability-training.htm
A gear pump uses two meshing, toothed cogs to force liquid from the inlet of the pump through to the outlet.
Being a positive displacement pump there deliver very precise quantities for each revolution, and this means they have good dosing characteristics
regardless of their speed or the pressure into which they discharge. Keywords: internal, external teeth, pressure relief, viscosity.
Excerpt: "The design of a gear pump lends itself to use with clean liquids. Ensure they draw liquid from well above the
bottom of the supply tank in clear liquid space. Both low and high viscosity liquids can be pumped. If food
grade products sensitive to shear (i.e., where the churning action of the pump breaks cells and fibers) are to be
pumped the size of the pump will need to be increased and the speed reduced."
64-page Excerpt from Process Hazards Analysis Book ( https://bin95.com/ebooks/hazop_risk_management.htm ) by Ian Sutton.
Process Hazards Analyses (PHAs) are an integral part of any process safety program. If you cannot identify hazards then you can neither remove them nor mitigate against them. This book describes in detail how to run a Process Hazards Analysis, and how to effectively identify hazards. The book focuses on real-world issues such as the role of the leader, team selection, writing the final report, quantification of risk, and follow-up to findings.
Quotations and topics raised in the book include the following:
* A PHA leader "comforts the afflicted but afflicts the comfortable"
* Don't confuse "common cause" with "root cause"
If it's not there, it can't leak
* Deciding whether to focus on high risk or on high consequence hazards
* The importance of MAWP values
* Distinguish between Findings, Recommendations, and Action Items
This book has been reviewed by the authoritative journal Chemical Engineering. A copy of that review is accessible at the link above.
This Machinery Failure Analysis and Troubleshooting handout is from our instructor-based PLC Training.
Learn more about troubleshooting at https://bin95.com/vocational-training/electrical/electrical-troubleshooting-plc-troubleshooting.htm
Understanding physics is the first and critical step to troubleshooting. Then we apply it to PLC troubleshooting, all in one simple handout page.
This Book https://bin95.com/ebooks/quality-course-management.htm is Currently Used At Universities And The Q-Course Foundation Exams Are Approved By State Ministry For Education.
This book is for everyone involved in quality in an organization. This book will help you obtain total quality management, a must-read for the organizational change management process. Also offers experience in testing & quality standards and methodologies of TMap, Testframe, ITIL, ISO 9001, TQM, Prince2, RUP, CMM, TMM, and ISEB.
The book excerpts here are ...
* Quality & Organization
* The Development Process
* Quality in the Project Organization
A 28-page sample from Process Risk Management book https://bin95.com/ebooks/risk_tree_analysis.htm by Ian Sutton.
The Process Risk Management EBook - Ian Sutton uses methods such as risk tree analysis combined with process safety information to help you gain an accurate operational risk assessment. This 272-page HSE book is a must-read for the HSE Manager and those studying process hazards analysis.
Excellent safety and environmental performance in the process industries does not happen by chance; after all, most process facilities handle large quantities of toxic, flammable, and explosive materials, often at high temperatures and pressure. Such processes are inherently hazardous. Therefore process risk must be properly understood and managed.
This simple equipment reliability example is used to convey the basics of reliability engineering. Learn the 4 system reliability factors that must all be addressed. Download the full 235 slide Reliability and Maintenance Management Course PowerPoint today at https://bin95.com/articles/maintenance-management/equipment-reliability-examples.htm
Before you seek SCADA Training, reading this #free article should be your first step. Then you will get #SCADA training that actually helps you succeed in the real world.
Answer to most simple PLC programming example we placed at https://www.slideshare.net/bin95/plcclock to see if those starting out with PLC programming could figure out how to fix. The fix is in, this it.
(Adam Bowman was the first one to find the problems in Quiz version of this program and give a detailed solution, congrats Adam. the version you are viewing here, PLCCLOCK-ANSW.rss is one possible working solution for the PLC clock program.)
This Siemens plc programming example PDF 2 is an expansion the counter PDF example 1.and has counter structured text programming example. Also a supporting video and more programming samples can be found at http://bin95.com/Siemens-Training/siemens-plc-programming-examples.htm
Free PLC training PowerPoint from the 1 hour webinar we did for the Association for Facilities Engineering. Of course with 30 slides and instructor notes for each, because as those who use our training know, we give extra. Actually we went over by 45 min on this PLC training and we didn't even talk about the extra PLC training slides in this one. We start with what is a PLC put in the most simplest form possible, and then get you a little taste of our best practice PLC training and approach from our PLC training seminars and on-site PLc training.
How IR Infrared Thermography Training and certification can greatly improve process and manufacturing reliability, increase electrical contractors and home improvement specialist's business revenue, and improve the individual's career opportunities. The Online Infrared Training Center opens new doors for both businesses and individuals. Watch and share this Infrared Thermography presentation to learn more.
PLC Networking Basics powerpoint downloadable and with instructor's notes to give more detail. This learning project is networking 5 computers to one Controllogix PAC (advanced PLC) via WiFi. PLC/PAC are automation controllers in process and manufacturing industries primarily. Although PLC/PAC are also used to control all infrastructure and have many niche applications. This basic networking mini course may be of interest to Maintenance, Maintenance Technician, Electrician, Industrial Electrician, Electrical Technician, Electromechanic Technician, Engineer, Engineering, Industrial Engineer, Control Engineer, Plant Engineer, Manufacturing Engineer, Instrument Tech, E/I, SCADA Technician, Controls Specialist, Process Control Technician, Service Technician, Field Service Technician, I&C Team Leader, Electrical Contractors, PLC Instructors, Electrical Instructors, Industrial Technology Instructors, Production Support Technician, Lead Technician, DCS Engineer, DCS Administrator, Water Treatment Specialist, Master Technician, Utility Technician, Technologist, Production Mechanic, HVAC Mechanic, Maintenance Superintendent, Engineering Manager, Project Engineer, Production Supervisor, IT Manager, Facility Service Supervisor and others.
PLC Networking Basics using a Controllogix module also has an associated interactive youtube course that uses an intro project of networking multiple class laptops to a single Controllogix 5000 PLC/PAC. This powerpoint is for reference and additional information to supplement the course at http://www.youtube.com/watch?v=Au03psa9Vxk The PLC Networking Basics course has a total of 4 training modules (videos), each with it's own question at end, before directing you to next Controllogix tutorial. There is also an associated test for this training course at http://bin95.com/Employee-Training-Assessments/PLC-Training-Assessment/PLC-Networking-Basics-Controllogix.php
Hope you like and share, which will encourage us to create more of these free courses.
This powerpoint has a video attached that help remind me of the pride the USMC bestowed on me and hopefully will you too. We are proud of our Veterans and thank you and your families for all you give and gave.
Instructions to help YOU support #WorkforceWednesdays next Wednesday. Like to contact your Senators or Representative to let them know NOT to consolidate and cut Federal Workforce Development programs like the WIA and a dozen more. #SaveOurSkills, #wkdev
Take your manufacturing company to the next level of Lean TPM with Autonomous Maintenance Level 2 Training Program. (Warning: May result in higher equipment operator ownership and increased equipment reliability. Also been known to result in higher company profits.) So consult your Lean manufacturing practitioners before using AM2 training program. :>)
1. FEED FORWARD FLYER
ADVANCING THE TECHNICAL KNOWLEDGE OF TRADESMEN AND PLANT OPERATORS.
From www.feedforward.com.au - The education site for plant operators and equipment maintainers.
ELECTRIC MOTOR PROBLEMS
ABSTRACT
Electric motor problems. This article presents a basic explanation of electric motor construction and
operation along with twelve problems that can be encountered with their use. Most electric motors in
industrial equipment are three phase alternating current induction motors. Induction is the creation of an
electric current across a gap. Two types of induction motors are commonly used: squirrel-cage and wound-
rotor. The names come from the way they are built. Keywords: motor characteristics, mounting, frame size.
INDUCTION MOTOR DESIGN
An electric motor consists of an iron rotor wheel mounted on a shaft, supported by bearings at each end,
spinning within a multi-coil cage of wire called a stator. Copper or aluminium bars are imbedded in the
outside surface of the rotor and connected together to form a circuit. The wire windings in the stator are
arranged to form an electromagnet. Figure 1 shows a simplified motor design. The electric currents flowing
through the outside stator coils create a magnetic field through the rotor while inducing an electric current in
the rotor bars.
POWER
SUPPLY SEPARATION STATOR
GAP COILS
STATOR IRON
COOLING CORE
FAN
ROTOR BAR
MOTOR
SHAFT
BEARINGS
FAN
COVER
ROTOR BAR
MOTOR FRAME
SHORTING RING
R.J. & R.S. NORMAN (Drafting Services)
E-Mail: rrdraft@optusnet.com.au
Figure 1. A simple cage induction electric motor design.
When alternating current (AC) flows through the stator coil, reciprocating north and south magnetic poles are
created at the ends of each coil. At the same time, like a transformer, the electric fields in the stator coils also
create an electric current in the rotor. When an electric current is cut by a moving magnetic field a reaction
force occurs in the current carrying conductor. The bars in the rotor, now induced with current, react in
response to the magnetic field and force the rotor to turn. The alternating magnetic field is then created in the
neighbouring coil and the rotor continues to turn.
For motion to be induced on the rotor the electric carrying conductor must cut the magnetic field. This
means the rotor must move slower than the cycling magnetic field. It is only by cutting through the lines of
magnetic force that torque is generated on the rotor. An electric motor will always run at a slightly slower
speed than the cycling magnetic field.
The motor speed depends on the number of separate magnetic fields created by the coils in the stator. A two-
pole motor has one coil and one magnetic field arranged around the stator, a four-pole motor has two coils
arranged around the stator with each winding placed between the other in sequence. A six-pole motor has
three coils with the windings spaced in sequence around the stator, and so on.
CHARACTERISTICS OF ELECTRIC MOTORS
The torque generated on the rotor and attached shaft results from the interplay of several electrical, magnetic
and physical variables that alter with the speed of the rotor.
Web Address: http://www.feedforward.com.au. E-mail Address: mailto:info@feedforward.com.au.
Because the authors and publisher do not know the context in which the information presented in articles is to be
used they accept no responsibility for the consequences of using the information contained or implied in any article.
2. When choosing an electric motor it is necessary to consider if the behavior of the load attached to the motor
is suited to the load characteristics of the electric motor. A rotor begins from rest and must come up to full
speed while dragging its load around with it. The electrical currents that occur within a rotor going through
start-up and operation vary greatly and influence the motor load carrying capacity.
PROBLEMS WITH ELECTRIC MOTORS
Below are a number of problems that are often encountered when using electric motors.
Water ingress into the motor will go between the stator coils or into the terminal box and short circuit
and burn out the motor. Water must never be allowed to get into a motor. If motors are to be used in wet
areas that must be of the correct ingress protection (IP) rating.
Overheating can occur from undersizing the motor, insufficient cooling at low speed when using
variable speed drives (VSD), changes to the load on the motor such as jammed equipment and hot
ambient conditions. Temperature detection (thermistor) and automatic shut down devices can be
installed. Attaching a separate booster fan to aid the motor fan solves the overheating problem when a
VSD is used to control the motor speed.
Bearing failure on motors can be an indication of the incorrect bearings for the application. A motor
mounted vertically needs different bearings to a motor mounted horizontally. A motor driving a large or
multi-belt drive will require bearings that handle big radial loads. A motor bolted to a distorted base plate
will twist (See Soft Foot). Check bearing types with the manufacturer.
Motors in-store or not in operation for long periods of time get false brinelled bearings where the
bottom bearings etch into the shaft. Turn the motor shaft a quarter turn monthly. Bearings in motors in-
store exposed to low vibrations through the ground can brinell. Sit motors on a sheet of 3-mm rubber to
insulate them from ground borne vibrations.
Burnt windings imply a short circuit either within the motor or within the power supply circuit for the
motor. Over-current protection can be installed as part of the power supply circuitry.
Dust ingress into the stator coils or the terminal housing leads to short-circuiting. If the motor is to be in
a dusty environment keep the immediate area around the motor clean or use dust ingress protection (DIP)
methods.
Hazardous area motors must comply with the type of hazard in the area. Motors in flammable vapours
like gasoline, in explosive vapour atmospheres and in explosive dust environments such as grain dust all
need to be rated and protected for the specific location. There are various methods of hazardous area
motor protection but they are not transferable across hazard types. For example a motor protected against
an explosive dust is not suitable to use in a flammable environment.
Temperature ratings of housings vary. The motor housings get hot under operation and there are six
different temperature ranges available for motors depending on the environment it must work in.
Running in reverse is a common problem. Changing over any two terminal leads changes the motor
direction. Always test run a motor to check direction after it is wired-up. Separate the shaft coupling to
protect the driven equipment from damage if necessary. Automatic current reversing relays are available
to provide the correct motor direction.
Shaft misalignment will destroy bearings well before their full working life. The motor shaft must be
directly in-line with the shaft it is driving. This can only be achieved by using precision alignment
techniques such as laser or dual dial indicators. The motor shaft must turn along its full length to within
0.05 mm (0.002”) of the true center of the driven shaft. This minimises the vibration, forces and loads
that planetary rotation of one shaft in respect to the other would create.
Soft foot occurs when the motor feet are bolted down out of level. If all feet are not in the same plane
when pulled down on the base plate the motor housing twists and the bearings are distorted. Put a
straight edge across the base plate and measure gaps with feeler gauges. Place the motor on a flat,
machined bed and check the gap under each foot. Put 316 stainless steel shims under the high feet to
level them when bolted down.
Wrong motor mounting or housing type leads to frustration. Motors are either foot mounted or flange
mounted. They come in various frame sizes and designs and the correct choice and delivery is needed.
Mike Sondalini – Maintenance Engineer
Postal Address: FEED FORWARD PUBLICATIONS, PO Box 578, BENTLEY, West Australia, 6102. E-mail Address: feedforward@bigpond.com
Because the authors and publisher do not know the context in which the information presented in the flyer is to be
used they accept no responsibility for the consequences of using the information contained or implied in any articles.