1-8
IM WT310E-01EN
Measurement range
5A
2A
1A
0.5A
When range skipping is off
When range skipping is on
Range skip check box
Peak Over Jump
You can set the measurement range to switch to when a peak over-range occurs and the auto range feature
is enabled. You can set this feature by sending communication commands through the communication
interface or by using WTViewerFreePlus. When this feature is disabled and a peak over-range occurs, this
instrument raises the measurement range to the next range that has not been set to be skipped.
Setting Measurement Ranges (For procedures, see section 2.3)
There are two ways to set measurement ranges.
Setting Measurement Ranges Using the Measurement Range Menu
The measurement range menu appears when you press VOLTAGE or CURRENT. Set the
measurement range using the ▼ and ▲ keys, and then press SET. The measurement range will
change, and the measured data display will reappear.
Setting Measurement Ranges without Displaying the Measurement Range Menu
The measurement range menu does not appear when you press VOLTAGE or CURRENT. You can
set the measurement range using the ▼ and ▲ keys.
Press ▼ or ▲ to switch the measurement range. For a fixed period of time, after the current range
is displayed, the measured data display will reappear.
There is no need to press SET, so this way of setting the measurement range is convenient in the
following situations.
• When you switch the measurement range frequently
• When you want to switch between measurement ranges one by one and check the measured
data each time
Example: When you are searching for a measurement range within which over ranges and peak
over-ranges do not occur.
Power Range
The measurement range (power range) for measuring active power, apparent power, and reactive
power is determined as indicated below in accordance with the wiring system, voltage range, and
current range. See appendix 3 for specific power range values.
Wiring System
Power Range
1P2W (single-phase, two-wire)
Voltage range × current range
1P3W (single-phase, three-wire)
3P3W (three-phase, three-wire)
3V3A (three-voltage, three-current method)
Voltage range × current range × 2
3P4W (three-phase, four-wire)
Voltage range × current range × 3
External Current Sensor Range (Option; for procedures, see
section 2.4)
The output of current sensors that produce voltage, such as shunts and clamps, can be applied to an
element’s external current sensor input terminal (EXT) and measured.
The auto range feature can be used for this applied voltage as well.
External Current Sensor Conversion Ratio (Option; for
procedures, see section 2.4)
Set the conversion ratio used to measure the signal received by the external current sensor input
terminal (EXT) from a current sensor that produces voltage. Set how many millivolts the current sensor
transmits when 1 A of current is applied (conversion ratio).
When using a current sensor that produces current, set the conversion ratio as the CT ratio.
1.2 Measurement Conditions
