How to Select AC Motors Image Credit: Baldor Electric Company | Demag Cranes and Components | ElectroCraft   AC motors are electric motors which are powered by alternating current (AC). They are used to convert electrical energy into mechanical energy in order to do work in a system. Specifically, rotational energy is produced by utilizing the force of magnetic fields induced by alternating current flowing through electric coils. AC motors are...
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Q & A on AC Motors

We asked our users for their input on AC Motors. Here are the results of 242 users familiar with AC Motors.

Who Took Our Poll? | Design Trends | Applications and Use | Features | Buying Advice

Who Took Our Poll?Top

Design TrendsTop

Q:
What new technologies are influencing AC motor design?
40 answers
Answers:
Well, that is a very large question to ask, the new design AC motors would definitely have to match the controlling circuitry and the purpose design for the equipment. Some motors have built in control circuits that are not interchangeable with other equipment uses.
~Reg J, General Management, Leduc, Canada
Development of solid state electronic drives like VFD, thyristors, soft starters Development of hybrid vehicle technology, battery technology Development in electromagnetic technology Design and analysis software
~Kian S, Engineer, Hubli, India
Monitoring equipment, motor attachments (types of encoders etc.), drives, more permanent magnet materials
~Bill C, Owner, Commerce, CA
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Q:
From your perspective, which companies are creating the most innovative AC motors?
37 answers
Answers:
I would say the newest manufacturing companies, as these companies have to compete with other competitors.
~Reg J, General Management, Leduc, Canada
Kirloskar Electric Company Limited Siemens
~Kian S, Engineer, Hubli, India
Mitsubishi Electric, Toshiba, ABB, Siemens
~Maintenance/Facilities Management, ISABEL , LEYTE, Philippines
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Applications and UseTop

Q:
What are some of the applications you have used AC motors for?
60 answers
Answers:
Now a days AC motor become more popular as they are simple in construction, relatively low manufacturing costs and less maintenance required. In all industries we can see the application of AC motors. From last few years AC motors are replacing the DC motors in electric traction drives. Below is the list of application of AC motors: In hybrid electrical vehicles like cars, motorcycles In compressors, crushers, pumps, conveyors, cranes, blowers In CNC machines, Lathe machines,etc In power grids In washing machines
~Kian S, Engineer, Hubli, India
As a prime mover for testing AC Generators, Textile Mills, Lathe Machines, Industrial Pumps, Flour Mills, Conveyors, Flame proof Motors in Coal Mines, Oil Mines etc.
~Quality Control/Assurance, Pune, India
Standard DOL and star delta starting for auxiliary and ancillary drive applications. Speed control applications to replace previous DC motor control applications.
~Engineering, Other, Rotterdam, Netherlands
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Q:
Please share with us any “non-standard” applications that AC motors have been used for.
19 answers
Answers:
Focusing cameras on space vehicles, rotating domes for space exploration, testing nuclear setting devices for nuclear subs, separating virus from blood in centrifuge (300,000 RPM) in AIDS research, test stands for aerospace and automotive applications, poi manufacturing, people moving rides at amusement parks.
~Bill C, Owner, Commerce, CA
The most frequent non-standard use I have made of AC motors is using them for positioning, as cost effective alternatives to servos where absolute highest performance is not required.
~Special projects consultant, Bradford, NH
Electric cars, go carts, wind generation, and in some cases depending on the design of the motor, small wind turbines.
~Reg J, General Management, Leduc, Canada
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Q:
Do you know of any disastrous mistakes that occurred due to the incorrect usage of AC motors?
18 answers
Answers:
Don't operate the induction motors under the locked rotor condition. Because under locked condition motor will draw very high in rush current usually 6 to 7 times of full load current. There is a chance of burning the motor and other equipment connected to same supply.
~Kian S, Engineer, Hubli, India
Yes, working for a large FMCG company they ordered the wrong motors for a complete new production line.
~Simon M, Engineering Consultant, Skipton, UK
I'm sure there have been cases of fire or machinery damage, none come to mind immediately.
~Special projects consultant, Bradford, NH
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FeaturesTop

Q:
What would your design or feature "wish list" be for this product?
27 answers
Answers:
For ease of production compatibility it has to be a controller circuit built on the outside of the motor casing that could if necessary be interchangeable to other motors of same horse power and size.
~Reg J, General Management, Leduc, Canada
Hazardous area motors to have the ability to add flanges to foot mounted motors without needing to open the motor, thereby potentially invalidating the safety.
~Project Management, MILTON KEYNES, Great Britain
Nothing comes quickly to mind. Current generation, high quality VFDs have control algorithms that accommodate most of the issues with AC motors.
~Special projects consultant, Bradford, NH
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Q:
Is there any advice you want to share with users to help them avoid common errors in selection or usage of AC motors?
20 answers
Answers:
Induction motors give the maximum efficiency at 85 to 100% Full load. Hence don't go for an over sized motor. For VFD application motor always prefer Class H insulation rather than Class F. To reduce the starting current effect use starters instead of DOL.
~Kian S, Engineer, Hubli, India
Frame selection and connection position. Beware of Y/delta start characteristics on change over with regard to installed protection devices.
~Peter K, Technical Support, Perth, West Australia
Explain your application to a knowledgeable salesman. Review the load profile, frequency of start and stops, transient loading, etc.
~Special projects consultant, Bradford, NH
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Buying AdviceTop

Q:
Do you have any advice for people relative to buying or using AC motors?
21 answers
Answers:
Check the voltage requirement, amount amps required, rpm's and the application that it is used for.
~Reg J, General Management, Leduc, Canada
Try to get some brand that can offer spare parts and maintenance advice near from you
~Juventino T, Facilities Manager, Lagos de Moreno, Mexico
Look for quality. Study the cost of energy...It is 97% of the cost of ownership.
~Bill C, Owner, Commerce, CA
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