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3-12
IM 760301-01E
3.7 Wiring for Making Accurate Measurements
To make accurate measurements, wire the voltage input terminal and current input
terminal by referring to the items below.
• Effects of Stray Capacitance
When measuring a single-phase device, the effects of stray capacitance on the
measurement accuracy can be minimized by connecting the current input terminal of
the instrument to the side that is close to the earth potential of the power source
(SOURCE).
SOURCE
LOAD
U
I
I
U
LOAD U
U
I
I
SOURCE
±
±
± ±
• Easily affected • Not easily affected
• Effects due to the Amplitude of the Measured Voltage and Current
SOURCE
LOAD
U
I I
U
LOAD
SOURCE
±
±
U
I I
U
±
±
• When the measurement current
is relatively large
Connect the voltage measurement
terminal to the load side.
• When the measurement current
is relatively small
Connect the current measurement
terminal to the load side.
Explanation
For details on the effects of stray capacitance and the effects due to the amplitude of the
measured voltage and current, see appendix 5, “For Making Accurate Measurements.”