GE Multilin
Sub Meters
29
Figure 3-2: Poly Phase System: (1) Delta, (2) Star (Wye)
3.2. Consumption & Poor PF
CONSUMPTION: WH = W x T, where W = instantaneous power T = time in hours
The total electric energy usage over a time period is the consumption of WH.
Typically, the unit in which consumption is specified is the kilowatt-hour (KWH): one
thousand watts consumed over one hour. Utilities use the WH equation to determine the
overall consumption in a billing period.
POOR POWER FACTOR: Results in reactive power consumption. Transferring reactive
power over a distribution network causes energy loss. To force consumers to correct their
Power Factor, utilities monitor reactive power consumption and penalize the user for Poor
Power Factor.
3.3. “3D” kVA Measurement
The EPM 2000 is equipped with 3D Measurement of kVA. This advanced method provides
the most accurate and predictable measurement under unbalanced as well as distorted
waveform conditions.
However, in case the EPM 2000 needs to match the reading of older or simpler meters which
use the Arithmetic kVA definition, this too is available as a Set-up option.
Table 3-1: VA Function Set up Options
kVA Function
Formula
Other Names Which one ?
3D (Factory setting)
+
+
=
2
2
2
3
D
VAR
W
kVA
D
where D = Distortion Power per IEEE 100
U, Apparent,
Vector kVA
Best, all around
Arith
Arithmetic,
Scalar kVA
Good under Low
unbalance, to
match simpler
meters without
3D capability
