405

Chapter 15

Power Control

The control of electrical power is a very important part of electrical
power system operation. Control is the most complex part of electrical
systems. It is, therefore, necessary to limit the discussion in this chapter
primarily to some of the common types of electromechanical equipment
used for electrical power control. Control equipment is used in conjunc-
tion with many types of electrical loads. Electrical motors (mechanical
loads) use about 50 percent of all electrical motor-control equipment. In
most cases, similar equipment is used to control electrical lighting and
heating loads.

IMPORTANT TERMS

Chapter 15 deals with power control equipment. After studying this
chapter, you should have an understanding of the following terms:

NEMA
ANSI
IEEE
Across-the-Line Starter Auxiliary Contact
Dynamic Braking
Normally Open Contact
Normally Closed Contact
Magnetic Contactor
Drum Controller
Jogging
Manual Starter
Overload Relay
Plugging
Normally Closed Pushbutton
Normally Open Pushbutton