IM 253401-01E
15-2
15.5 Computing Functions
Effective Power
(W)
1-phase
2-wire
W
VA=V
×
A
(VA) –W
Apparent Power
(VA)
Power Factor
(PF)
Phase Angle
(deg)
Reactive Power
(var)
2
2
W
VA
W
VA
=cos ( )
–1
1-phase 3-wire
3-phase 3-wire
(two power meter method)
3-phase 3-wire
(three power meter method)
3-phase 4-wire
Computation
W
i
i
=1, 3
Σ
W
=W
1
+W
3
W
i
i
=1, 3
Σ
W
=W
1
+W
3
W
i
i
=1,2,3
Σ
W
=W
1
+W
3
W
i
i
=1,2,3
Σ
W
=W
1
+W
2
+W
3
VA
i
=V
i
×
A
i
i
=1, 3
Σ
VA
=VA
1
+VA
3
VA
i
=V
i
×
A
i
i
=1, 3
2
2
var
i
=
(VA
i
) –W
i
i
=1, 3
W
i
VA
i
PF
i
=
i
=1, 3
–1
W
i
VA
i
ϕ
i
=
cos ( )
i
=1, 3
Σ
var
=var
1
+var
3
2
2
var
i
=
(VA
i
) –W
i
i
=1, 3
Σ
var
=var
1
+var
3
2
2
var
i
=
(VA
i
) –W
i
i
=1,2,3
Σ
var
=var
1
+var
3
2
2
var
i
=
(VA
i
) –W
i
i
=1,2,3
Σ
var
=var
1
+var
2
+var
3
Σ
W
Σ
VA
Σ
PF
=
W
i
VA
i
PF
i
=
i
=1, 3
Σ
W
Σ
VA
Σ
PF
=
W
i
VA
i
PF
i
=
i
=1,2,3
Σ
W
Σ
VA
Σ
PF
=
W
i
VA
i
PF
i
=
i
=1,2,3
Σ
W
Σ
VA
Σ
PF
=
–1
Σ
W
Σ
VA
Σϕ
=
cos ( )
–1
W
i
VA
i
ϕ
i
=
cos ( )
i
=1, 3
–1
Σ
W
Σ
VA
Σϕ
=
cos ( )
–1
W
i
VA
i
ϕ
i
=
cos ( )
i
=1,2,3
–1
Σ
W
Σ
VA
Σϕ
=
cos ( )
–1
W
i
VA
i
ϕ
i
=
cos ( )
i
=1,2,3
–1
Σ
W
Σ
VA
Σϕ
=
cos ( )
Σ
VA
=
(VA
1
+VA
3
)
3
2
VA
i
=V
i
×
A
i
i
=1,2,3
Σ
VA
=
(VA
1
+VA
2
+VA
3
)
3
3
VA
i
=V
i
×
A
i
i
=1,2,3
Σ
VA
=
VA
1
+VA
2
+VA
3
Computating
Range
Depends on
the selected
V and A ranges
Depends on the
selected V and A
ranges
Same as apparent
power (var
≤
0)
-1 to 0 to 1 -180 to 0 to 180
Display
resolution
10000
10000
10000
±
1.000
±
180.0
Computing
accuracy (for
the value
operated from
the measured
value)
—
±
0.005% of
VA range
±
0.005% of
var range
±
0.0005
Resolution
(power factor
±
0.0005)
Note 1: The apparent power (VA), reactive power (var), power factor (PF), and phase angle
(deg) measurements in this instrument are computed digitally from the voltage,
current and effective power. If the input is non-sinusoidal, the measured values may
differ from those obtained with instruments employing different measurement
principles.
Note 2: When the current or voltage is less than 0.5% of the range, the VA and var will be
displayed as 0, and PF/deg will be displayed as an error.
Note 3: The Lead and Lag are displayed for V and A input at 50% or more. The detected
lead/lag accuracy is
±
5 degrees over the frequency range of 20 Hz to 2 kHz.
15.6 Display Functions
Display type:
7-segment LED
Number of displays:
3
DISPLAY
A
B
C
* Vpk, Apk, and MATH are supported only for ROM versions 2.01 or later.
V, A, W : 9999
Wh, Ah : 999999
V, AHz : 9999
V, A, W, VA, var (each element), elapsed integration time
V, A, W, PF, deg (each element), % (contents ratio in %, THD)
V, A, W, V
⋅
AHz,
±
Wh,
±
Ah (each element)
Vpk*, Apk*, MATH*
Displayed Value
Maximum Reading
Unit:
m, k, M, V, A, W, VA, var, Hz, h
±
, deg, %
Display update rate:
4 times/s
Response time:
Approximately 0.5 s (time for displayed value to settle within
accuracy specifications of final value after step change from 0% to
100% or 100% to 0% of rated range)
Display scaling function Significant digits:
Selected automatically according to
significant digits in the voltage and current ranges
Reassign ratio:
0.001 to 1000
Averaging function:
The following two algorithms can be selected:
Exponential averaging
Moving averaging
Response can be set; for exponential averaging, the attenuation
constant can be selected and for moving averaging, the number of
averages (N) can be set to 8, 16, 32, or 64.
Peak over range display The alarm LED will light up when the RMS value is greater than
140% of the range or the peak value is greater than 300% of the
range.
15.7 Integrator Function
Display resolution:
Depending on elapsed time value, the resolution will be changed.
Maximum display:
–99999 to 999999 MWh (or MAh)
Modes:
Standard integration mode (timer mode)
Continuous integration mode (repeat mode)
Manual integration mode
Timer:
When the timer is set, integration will be stopped automatically.
Setting range: 000 h:00 min to 999 h:59 min (000 h:00 min will be
shown when manual integration mode is selected automatically.)
Count overflow:
If the integration count flows above 999999 MWh (or MAh) or below
–99999 MWh (or MAh), integration stops and the elapsed time is
held on the display.
Accuracy:
±
(display ac 0.2% of rdg) However, only when the input
signal is continuous.
Timer accuracy:
±
0.02%
Remote control:
Start, stop, and reset can be remotely controlled by external
contact signals.
However, the /DA4 or /DA12 options must be installed.
15.8 Internal Memory Function
Measurement data
Number of data that can be stored:
WT110 (253401): 600 blocks
WT130 (253502): 300 blocks
WT130 (253503): 200 blocks
Each block has following data:
measurement setting mode, measurement ranges, V, A, W,
Wh+, Wh-, Ah+, Ah-, elapsed time and frequency
Writing intervals: 250 ms and 1 s to 99 h: 59 min: 59 s
Reading intervals: 250 ms and 1 s to 99 h: 59 min: 59 s (both
intervals can be set on a second basis)
Panel setup information: Four-pattern information can be written/read.
15.9 D/A Converter (optional)
Output voltage:
±
5 VDC FS (approximately
±
7.5 V maximum) at rated value or
range Number of output channels: 12 when the /DA12 option is
installed; 4 when the /DA4 option is installed
Output data selection:
Can be selected for each channel.
Accuracy:
±
(Display ac 0.2% of range)
Update rate:
Identical to display update interval
Temperature coefficient:
±
0.05% of f.s./
°
C
• Frequency
D/A output
Displayed value [Hz]
4
0.2V
0.5V
2.5V
5.0V
10
100
1k
10k
50k
Approx. 7.5V
• Integration
D/A output
Approx. 7.0V
5.0V
0
t
0
Integration time
140% input of the rated value
Rated value input
t
0
: Rated value setting time
• Other items
D/A output
0V
–100%
–140%
–5.0V
Approx. –7.0V
Approx. –7.5V
5.0V
Approx. 7.0V
Approx. 7.5V
140%
100%
Displayed value
140%
100%
0%
–100%
–140%
Output
Approx. 7.0V
5.0V
0V
–5.0V
Approx. –7.0V
However, for PF and deg,
points in the range from +5
to +7 V and from –5 to –7 V
are not output. If there is
an error, the output will be
about
±
7.5 V.
Displayed
value
Chapter 15 Specifications