Basic AC Power
OBJECTIVES
TERMINAL OBJECTIVE
1.0
Given an AC single-phase or three-phase circuit, DESCRIBE the power characteristics
in the circuit.
ENABLING OBJECTIVES
1.1
DESCRIBE the relationship between apparent, true, and reactive power by definition
or by using a power triangle.
1.2
DEFINE power factor as it relates to true power and apparent power.
1.3
Given the necessary values for voltage (E), resistance (R), reactance (X), impedance
(Z), and/or current (I), CALCULATE the following power components for an AC
circuit:
a.
True power (P)
b.
Apparent power (S)
c.
Reactive power (Q)
d.
Power factor (pf)
1.4
DEFINE the following terms:
a.
Leading power factor
b.
Lagging power factor
1.5
STATE the reasons that three-phase power systems are used in the industry.
1.6
Given values for current, voltage, and power factor in a three-phase system,
CALCULATE the following:
a.
Real power
b.
Reactive power
c.
Apparent power
1.7
Given a diagram of a wye- or delta-connected three-phase system, DESCRIBE the
voltage/current relationships of the circuit.
1.8
STATE the indications of an unbalanced load in a three-phase power system.
Rev. 0
Page v
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