208 Electrical Power Systems Technology
Secondary Winding
Transformer Core
Closed-Core Transformer Construction
Shell-Core Transformer Construction
Efficiency
Power Losses
Step-Up Transformer
Step-Down Transformer
Transformer Voltage Ratio
Transformer Current Ratio
Multiple Secondary Transformer
Autotransformer
Transformer Polarity
Transformer Volt-Ampere Rating
Transformer Malfunction
Conductor
Circular Mil (cmil)
American Wire Gauge (AWC)
Resistivity
Ampacity
Insulation
OVERVIEW OF ELECTRICAL POWER DISTRIBUTION
The distribution of electrical power in the United States is normally in
the form of three-phase, 60-Hz alternating current. This power, of course, can
be manipulated or changed in many ways by the use of electrical circuitry.
For instance, a rectification system is capable of converting the 60-Hz AC
into a form of DC, as was discussed in Chapter 7. Also, single-phase power
is generally suitable for lighting and small appliances, such as those used
in the home or residential environment. However, where a large amount
of electrical power is required, three-phase power is more economical.
The distribution of electrical power involves a very complex system
of interconnected power transmission lines. These transmission lines orig-
inate at the electrical power-generating stations located throughout the
United States. The ultimate purpose of these power transmission and dis-
tribution systems is to supply the electrical power necessary for industrial,
residential, and commercial use. From the point of view of the systems, we