Three-Phase System - GE EPM 5300 Instruction Manual

CHAPTER 1: AC POWER MEASUREMENT
Ideal power distribution should have a PF of 1. This condition can be met only if no reactive power
loads exist. In real life applications, many loads are inductive loads. Often, corrective capacitors are
installed to correct Poor Power Factor (see Section 1.3).

1.2: Three-Phase System

A three-phase system delivers higher levels of power for industrial and commercial applications; the
three phases correspond to three potential lines. A 120° phase shift exists between the three potential
lines.
A typical configuration has either a Delta connection or a Wye connection (see Figure 1.3, below).
In a three-phase system, the voltage levels between the phases and the neutral are uniform and defined
by:
E E
= = = =
E E E ab bc
an bn cn
3 3
2
Apparent Power (VA)
Real Power (W)
Figure 1.2: Relationship between apparent, real
and reactive power
E
=
ac
3
C
A
Figure 1.3: Three-Phase System: (1) Delta, (2) Wye
EPM 5000 series Advanced Power Meters
Reactive
Power
(VAR)
A
1) Delta
B
B
2) Wye
N
C
GE Multilin