YOKOGAWA WT310EH User Manual

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

YOKOGAWA WT310EH Specifications

General

Brand	YOKOGAWA
Model	WT310EH
Category	Measuring Instruments
Language	English