1-9
IM WT310E-01EN
Features
1
2
3
4
5
6
7
8
App
Index
Scaling (For procedures, see section 2.5)
You can set coefficients for when you apply a voltage or current signal from an external voltage
transformer
1
or current transformer.
2
1 VT (voltage transformer)
2 CT (current transformer)
VT Ratio and CT Ratio
You can set the VT or CT ratio to convert the values in the applied signal and display the voltage or
current values or waveform from before the voltage or current transformation.
Power Coefficient
By setting the power coefficient (F), you can display the measured active power, apparent power, and
reactive power after they have been multiplied by a coefficient.
Measurement Function
Data before Transformation
Transformation Result
Voltage U
U
2
(secondary output of the VT)
U
2
×V
V: VT ratio
Current I
I
2
(secondary output of the CT)
I
2
×C
C: CT ratio
Active power P
P
2
P
2
×V×C×F
F: Power coefficient
Apparent power S
S
2
S
2
×V×C×F
Reactive power Q
Q
2
Q
2
×V×C×F
Max./min. voltage Upk
Upk
2
(secondary output of the VT)
Upk
2
×V
Max./min. current Ipk
Ipk
2
(secondary output of the CT) Ipk
2
×C
Crest Factor (For procedures, see section 2.7)
The crest factor is defined as the ratio of the peak value of the waveform to the rms value. It is also
referred to as the peak-to-rms ratio.
Peak value
Rms value
Crest factor (CF, peak-to-rms ratio) =
Peak value
Rms value
Input signal waveform
On this instrument, the crest factor is the ratio of the maximum applicable peak value to the
measurement range.
Peak value that can be input
Measurement range
Crest factor (CF, peak-to-rms ratio) =
You can set the crest factor to 3, 6 or 6A. The measurable crest factor is as follows.
{Measurement range × CF setting (3 or 6)}
Measured value (rms value)
Crest factor (CF) =
* However, the peak value of the input signal must be less than or equal to the maximum allowable
input.
If the crest factor of the input signal is greater than the specifications of this instrument (the crest factor
defined at the rated input), you can measure the signal by setting a greater measurement range. For
example, even if the crest factor is set to 3, measurement is possible for signals with a crest factor
greater than or equal to 5 when the measured value (rms value) is less than 60% of the measurement
range. If the minimum effective input (1% of the measurement range) is being applied when the crest
factor is set to 3, measurement at a crest factor of 300 is possible.
The voltage range, current range, effective input range, and measurement accuracy vary depending
on the crest factor setting. For details, see chapter 7 in the Getting Started Guide, IM WT310E-02EN.
1.2 Measurement Conditions
