Publication Date: July, 2005 Discount Price:$17.50 (Cdn) Discount Price:$14.99 (U.S.)

AC Motors Volume 2

AC motors typically consist of two parts:

An outside stationary stator having coils supplied with AC current to produce a rotating magnetic field, and; An inside rotor attached to the output shaft that is given a torque by the rotating field. There are two fundamental types of device depending on the type of rotor used:

Synchronous ac motors, which rotate exactly at the supply frequency or a submultiple of the supply frequency, and; Induction ac motors, which turn slightly slower, and typically (though not necessarily always) takes the form of the squirrel cage motor.

Three-phase induction AC motors

A three phase AC induction motor rated 1 Hp (746 W) and 25 W with a small motor from CD player, toy and CD/DVD drive reader head traverseWhere a polyphase electrical supply is available, the three-phase (or polyphase) AC induction motor is commonly used, especially for higher-powered motor devices. The phase differences between the three phases of the polyphase electrical supply create a rotating electromagnetic field in the motor.

Through electromagnetic induction, the rotating magnetic field induces a current in the conductors in the rotor, which in turn sets up a counterbalancing magnetic field that causes the rotor to turn in the direction the field is rotating. The rotor must always rotate slower than the rotating magnetic field produced by the polyphase electrical supply; otherwise, no counterbalancing field will be produced in the rotor.

Induction ac motors are the workhorses of industry and up to about 500 kW (670 horsepower) in output are produced in highly standardized frame sizes, making them nearly completely interchangeable between manufacturers (although European and North American standard dimensions are different). Very large synchronous motor devices are capable of tens of thousands of kW in output, for pipeline compressors and wind-tunnel drives.

Our Electric Motor Handbook examines how these important devices play a critical role in all aspects of our modern society. More than 50 per cent of all electricity generated is consumed by ac motors.

In fact, 75 per cent of all industrial electricity consumption is consumed by this equipment. In order to select and apply the correct size electric motor, electrical personnel must be aware of all factors involved: energy efficiency, sizing and proper application. equipment management (protection, control and maintenance) is also critical to achieving efficient use and maximum life expectancy.

This 96 page book will present articles from leading experts on selection, how they work, application, protection and control, maintenance and troubleshooting in modern electrical systems.

• Glossary of Electric Motor Terms
• Maintenance and Troubleshooting of Electric Motors (scheduled routine care; bearing lubrication; heat, noise and vibration; windings; brush and commutator care)
• Application of High Temperature Mold Materials to Die Cast the Copper Motor Rotor
• Application of the EL CID Test with Circulating Currents in Stator Windings
• Electronic AC Motor Diagnostics
• Field Testing of Electric Motor Devices
• Motor Testing: Identifying Motor Defects Through Fault Zone Analysis
• Motor Testing: Improving Motor Reliability Through Static and Dynamic Testing
• Induction - Protection and Starting
• Magnetic Finite Element Analysis for a Motor Protector and Edge Arcing Elimination
• Bearings for Extreme Environments
• Need for Industry Standards for AC Induction Intended for Use with Adjustable-Frequency Controllers
• Proper Motor Lubrication

  Purchase Motors Handbook Vol. 2 and get Motors Handbook Vol. 1 for half price!! Only $33 for both handbooks!!!

• DC Motor Brush Life
• AC Induction Motors
• BUYER’S GUIDE
  -- 140+ Pages