Line and Phase Voltages for a Wye Circuit

Currents for a Wye Circuit

Line and Phase Currents for a Delta Load

The Single-Phase Equivalent

Summary

EXAMPLE 23–6

Single phase equivalent

EXAMPLE 23–8

Single phase equivalent

Solution

Find the  currents.

EXAMPLE 23–10

Single phase equivalent

Power in a Balanced System

Active Power to a Balanced Wye Load

Reactive Power to a Balanced Wye Load

Apparent Power

Power Factor

EXAMPLE 23–11

Solution

Solution (cont.)

Power to a Balanced Delta Load

Power Formulas for Balanced Wye and Delta Circuits

EXAMPLE 23–12

Solution

Power and the Single-Phase Equivalent EXAMPLE 23–13

single-phase equivalent

Measuring Power in Three- Phase Circuits

Three-wattmeter connection for a 4-wire load

Two-wattmeter connection

EXAMPLE 23–14

Solution

Unbalanced Load

EXAMPLE 23–16

E AB = 208 V ∠ 0° and E BC = 208 V ∠ 120°.

EXAMPLE 23–17

EXAMPLE 23–18 wattmeter readings?

Circuit Analysis Using Computers