7-9
IM WT310-02EN
Specifications
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App
Index
7.4 Functions
7.4.1 Voltage, Current, and Active Power Measurements
Item
Specifications
Measurement method
Digital sampling method
Crest factor
3 or 6
Wiring system
WT310, WT310HC (One element model)
Single-phase, two-wire (1P2W)
WT332 (Two element model)
Select single-phase, two-wire (1P2W); single-phase, three-wire (1P3W); or three-phase, three-
wire (3P3W).
WT333 (Three element model)
Select single-phase, two-wire (1P2W); single-phase, three-wire (1P3W); three-phase, three-wire
(3P3W); three-phase, four-wire (3P4W); or three-voltage, three-current (3V3A).
Range select
Select manual or auto ranging.
Auto range
Range increase
The range is increased when any of the following conditions is met.
• Urms or Irms exceeds 130% of the currently set measurement range.
• Crest factor 3: Upk , Ipk value of the input signal exceeds 300% of the currently set
measurement range.
• Crest factor 6: Upk , Ipk value of the input signal exceeds 600% of the currently set
measurement range.
On the WT332/WT333, when any of those input elements meets the above condition, the
range is increased the next time the measured value is updated.
Range decrease
The range is decreased when all of the following conditions are met.
• Urms or Irms is less than or equal to 30% of the measurement range.
• Urms or Irms is less than or equal to 125% of the next lower measurement range.
• Crest factor 3: Upk , Ipk value of the input signal exceeds 300% of the currently set
measurement range.
• Crest factor 6: Upk , Ipk value of the input signal exceeds 600% of the currently set
measurement range.
On the WT332/WT333, when all of the input elements meet the above conditions, the range is
decreased the next time the measured value is updated.
Display mode switching
Select RMS (the true RMS value of voltage and current), VOLTAGE MEAN(the rectified mean value
calibrated to the RMS value of the voltage and the true RMS value of the current), or DC (simple
average of voltage and current).
Measurement
synchronization source
Select voltage, current, or the entire period of the data update interval for the signal used to achieve
synchronization during measurement.
Line filter
Select OFF or ON (cutoff frequency at 500 Hz).
Peak measurement
Measures the peak (max, min) value of voltage, current, or power from the instantaneous voltage,
instantaneous current, or instantaneous power that is sampled.
Zero-level compensation
Removes the internal offset of the WT300 series.