Motores Ac

Table of Contents

Introduction ..............................................................................2
AC Motors ................................................................................4
Force and Motion .....................................................................6
Energy ................................................................................... 11Electrical Energy ................................................................... 13
AC Motor Construction ......................................................... 17
Magnetism............................................................................. 23
Electromagnetism ................................................................. 25
Developing a Rotating Magnetic Field.................................. 31
Rotor Rotation ....................................................................... 37
Motor Specifications ............................................................. 42
NEMA Motor Characteristics ................................................ 46
Derating Factors .................................................................... 54
AC Motors and AC Drives.................................................... 56
Matching AC Motors to the Load ......................................... 61
Enclosures ............................................................................. 67
Mounting ............................................................................... 71
Siemens Motors ................................................................... 78Above NEMA Motors ........................................................... 83
Review Answers ................................................................... 88
Final Exam ............................................................................. 89

1

Introduction

Welcome to another course in the STEP 2000 series, Siemens
Technical Education Program, designed to prepare ourdistributors to sell Siemens Energy & Automation products
more effectively. This course covers AC Motors and related
products.
Upon completion of AC Motors you should be able to:

•
•

Explain the difference between work and power

•

Describe the construction of a squirrel cage AC motor

•

Describe the operation of a rotating magnetic field

•

Calculate synchronous speed,slip, and rotor speed

•

Plot starting torque, accelerating torque, breakdown
torque, and full-load torque on a NEMA torque curve

•

Apply derating factors as required by an application

•

Describe the relationship between V/Hz, torque, and
horsepower

•

Match an AC motor to an application and its load

•

Identify NEMA enclosures and mounting configurations

•Describe Siemens Medallion™, PE-21 Plus™, vertical
pump, and IEC motors

•

2

Explain the concepts of force, inertia, speed, and torque

Describe torque characteristics and enclosures of
Siemens above NEMA motors

This knowledge will help you better understand customer
applications. In addition, you will be better able to describe
products to customers and determine important differencesbetween products. You should complete Basics of Electricity
before attempting AC Motors. An understanding of many of
the concepts covered in Basics of Electricity is required for
AC Motors. You may also want to complete Basics of Control
Components which discusses the application of control
devices for start, stop, and thermal protection of AC motors.
If you are an employee of a SiemensEnergy & Automation
authorized distributor, fill out the final exam tear-out card and
mail in the card. We will mail you a certificate of completion if
you score a passing grade. Good luck with your efforts.
Medallion and PE-21 Plus are trademarks of Siemens Energy
& Automation, Inc.
National Electrical Code® and NEC® are registered trademarks
of the National Fire Protection Association,...