Valhalla 2300, Operation Manual

Page: 31 / 115

6-4-23. Three-phase Four-Wire PT
Source Power Connections
Some applications require measuring the
power from a source rather than the power
into a load. These connections are shown in
Figure 6-23. When the Model 2300 is used in
this manner, the watts reading should be
multiplied by minus one (-1) and the PT ratio.
Observe the polarities of the potential
transformers. Caution! Do not exceed the
common mode specifications of the Model
2300.
6-4-24.
Three-phase, Four-Wire CT-PT
Source Power Connections
Some applications require measuring the
power from a source rather than the power
into a load. These connections are shown in
Figure 6-24. When the Model 2300 is used in
this manner, the watts reading should be
multiplied by minus one (-1) and the CT-PT
ratios. Observe the polarity of the current and
potential transformers. For best performance
the CURRENT COMMON terminals should
be grounded.
6-5. Single-Phase Measurements
The power consumed by a single-phase load
or the power supplied by a single-phase
source may be easily measured with a Model
2300 or 2301. Three independent single-
phase measurements can be made at the same
time with the 2300. The following guidelines
should be used when making a single-phase
power measurement:
1) Connect the 2300 as shown in Figures 6-1
to 6-8 as determined by your application.
Make connections to the appropriate
current shunt terminal for the expected
range of current levels.
2) Press the appropriate
φ
A,
φ
B, or
φ
C
display selection push-button for the
channel connected.
3) Select the lowest current range that
provides the required display resolution
without the current peak overload LED
illuminating.
4) Select the lowest voltage range that
provides the required display resolution
without the voltage peak overload LED
illuminating.
5) Read the voltage, current and power on
the three displays. When measuring the
power supplied by a source, multiply the
power measurement by negative one (-1)
to obtain the correct watts polarity.
6) The displays may be frozen indefinitely
by pressing the HOLD push-button.
6-6. Three-Phase Three-Wire
Measurements
The power consumed by a three-phase three-
wire connected load or the power supplied by
a three-phase three-wire source may easily be
measured with a 2300. The following
guidelines should be used when making these
measurements (also refer to AN104):
1) Connect the 2300 as shown in Figures 6-9
to 6-16 as determined by your application.
Make connections to the appropriate
current shunt terminals for the expected
range of current levels.
2) Press the 3
φ
3-WIRE display selection
push-button.
3) Select the lowest current range without
illuminating any of the peak current
overload indicators.
4) Select the lowest voltage range without
illuminating any of the peak voltage
indicators.
5) The total true power may be read
on the watts display.