25
IM 701450-61E
Supply voltage of the equipment under test (system voltage)
Set the supply voltage of the equipment on which to perform harmonic computation. The
harmonic limit defined by the harmonic current emissions standard (see page 5) is converted
5
using the supply voltage and used as the criteria. The default value is 230 V.
•
Selectable range
90 to 440 V
•
Resolution
1 V
Applicable class
6
(Class)
Select the applicable class for the equipment under test. The harmonic current emissions
standard classifies the equipment under test into Class A through D, and criteria are specified for
each class.
•
Additional items set for Class C
6
Active power of the equipment under test (Over 25 watt)
Select whether the active power of the equipment under test exceeds 25 W. For Class C, the
criteria vary depending on the active power of the equipment.
Fundamental current of the equipment under test (Max Fund Current)
Set the fundamental current when the load on the equipment under test is set to maximum.
To set the maximum current measured on the DL7400, perform harmonic computation with the
maximum load, and then set the value that is displayed in the Max box in the list that appears
when you select Show List. For Class C, evaluation is made on the percentage of the harmonic
component with respect to the maximum fundamental current of the equipment under test.
Power factor (
λ
)
If the active (input) power of the equipment under test exceeds 25 W (True), set the power
factor when the load on the equipment under test is set to maximum. On the DL7400, set the
power factor that is measured according to the procedure given in section 5. For Class C, if
the active (input) power of the equipment under test exceeds 25 W, the circuit power factor
when the equipment load is set to maximum is used when evaluating the percentage of the
3rd order harmonic component with respect to the fundamental current.
•
Default value
0.800
•
Selectable range
0 to 1.000
•
Resolution
0.001
•
Additional items set for Class D
6
Active power of the equipment under test
Set the active power of the equipment under test. For Class D, the harmonic current per watt
(power ratio limit) is also evaluated.
Displaying the computed results
•
Bar graph display
The harmonic measurement data and the standard limits for each order up to the 40th order
can be displayed on a bar graph. You can set the scale to LIN (linear) or LOG (logarithmic).
•
List display (Show List)
The harmonic measurement data and the standard limits for each order up to the 40th order
can be listed.
5 Conversion of limits using the supply voltage
The harmonic current emissions standard defines limits of harmonics for each order by
assuming 220 V, 230 V, and 240 V for the supply voltages of the equipment under test (single
phase). For other supply voltages, the limits need to be converted. The power analysis
function of the DL7400 uses the following equation to convert the limits of all classes
excluding the range of 220 V to 240 V.
Converted limit = Limit of each class
×
230
Supply voltage of equipment (rated voltage)
6 For details on each item, see the standard given on page 5 in this manual.
Note
•
The DL7400 can only compute the harmonics of single-phase equipment. It cannot compute
the harmonics of three-phase equipment.
•
The computed results of harmonics obtained through this function do not accurately comply with the
standard. To make accurate measurements complying with the standard, the WT2000 Series Digital
Power Meter and Harmonic Analysis Software (Model 761922) are required.
•
You cannot perform history search on the computed results of harmonics.
•
You cannot perform GO/NO-GO determination on the computed values of harmonics
(measured values of waveform parameters).
•
Of the computed results of harmonics, the computed values of each harmonic component
and the limits defined by the standard can be saved to a file in CSV format (see section 11 in
this manual). The waveform data of harmonics cannot be saved.
•
The original waveform data used to compute the harmonics can be saved. If the original waveform
data is saved in binary format, harmonic computation described in this section can be performed by
loading the data into the DL7400 with the Power Analysis Function (/G4 option). For instructions on
saving the data in binary format, see section 12.7 in the
DL7440/DL7480 User’s Manual
.
7 Performing Waveform Computation on Power Analysis Parameters
