5-11
IM 253710-01E
Setting the Measurement Mode and Range
5
• Auto range
Select [Auto] for the range setting to enable auto range. The range switches
automatically depending on the amplitude of the input signal as follows. The
different ranges used in the auto mode are the same as those available for fixed
range selection.
• Increasing the range
• When the numerical data U+pk and U-pk exceed 80% of the current voltage
range, the voltage range is increased for the next data acquisition.
• When the numerical data I+pk and I-pk exceed 80% of the current current
range, the current range is increased for the next data acquisition.
• Decreasing the range
• When the numerical data U+pk and U-pk fall below 15% of the current
voltage range, the voltage range is decreased for the next data acquisition.
• When the numerical data I+pk and I-pk fall below 15% of the current current
range, the current range is increased for the next data acquisition.
Note
•
When numerical data are not measured or computed (see section 10.1), auto range cannot
be used. You can select [Auto] from the menu, but it is not activated. The range that was
most recently selected is used.
•
When pulse waveforms that are not periodic are input during auto range, the range may not
remain constant. In this case, use a fixed range setting.
•
When measuring input signals that include pulse waveforms through a line filter, the range
may not be set correctly by the auto range function, and measurements may be inaccurate.
When measuring such input signals as PWM inverter waveforms, It is recommended that you
perform the measurements using the fixed range determined by the PWM crest value.
Power range
The measurement ranges (power range) of active power (P), apparent power (S), and
reactive power (Q) are as follows.
Wiring Method
Power Range
1P2W (single-phase two-wire)
voltage range
×
current range
1P3W (single-phase three-wire)
voltage range
×
current range
×
2
3P3W (three-phase three-wire)
(when the voltage and current ranges on the
3V3A (three-voltage, three-current)
corresponding elements are set to the same range)
3P4W (three-phase four-wire)
voltage range
×
current range
×
3
(when the voltage and current ranges on the
corresponding elements are set to the same range)
• When the result of the voltage range
×
current range exceeds 1000 W (VA, or var),
the displayed unit changes to kW (kVA or kvar).
• The maximum displayed value is 99999 (5 digits) or 999999 (6 digits). For digit
selection, see section 8.1, “Selecting the Number of Displayed Digits.”
Note
Because the voltage and current ranges switch independently according to the input
conditions, different power ranges may be set for the same power value.
5.3 Setting the Measurement Range during Direct Input
