2-31
IM WT310-02EN
Making Preparations for Measurements
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App
Index
2.10 Wiring the Circuit under Measurement When
Using Current Sensors
To prevent electric shock and damage to the instrument, follow the warnings given in section 2.5,
“Precautions When Wiring the Circuit under Measurement.”
If the maximum current of the circuit under measurement exceeds the maximum range of the input
elements, you can measure the current of the circuit under measurement by connecting an external
current sensor to the external current sensor input connector.
• WT310 and WT330
When the maximum current exceeds 20 Arms
• WT310HC
When the maximum current exceeds 40 Arms
Current Sensor Output Type
Voltage Output
Refer to the wiring examples in this section when using a shunt-type current sensor or a clamp-type
current sensor that outputs voltage.
Current Output
If you are using a clamp-type current sensor that outputs current, see section 2.11.
Connecting to the Input Terminals
Voltage Input Terminals
The terminals are safety banana jacks (female) that are 4 mm in diameter.
Only insert a safety terminal whose conductive parts are not exposed into a voltage input terminal.
If you are using the included 758931 Safety Terminal Adapter, see section 2.6.
External Current Sensor Input Terminal
The terminal is an isolated BNC connector.
Connect an external current sensor cable with an isolated BNC connector (B9284LK, sold separately)
to an external current sensor input connector.
Shunt-type current sensor
I
±
OUT H
OUT L
External current sensor input connector
B9284LK
WT310/WT310HC
WT330
Remove the measurement cable connected to the current input terminal. Because the external current
sensor input terminal and the current input terminal are connected internally, connecting both terminals
simultaneously not only results in measurement errors but may also cause damage to the instrument.
Also, when the voltage of the circuit under measurement is being applied to the external current sensor
input terminals, do not touch the current input terminals. Doing so is dangerous because the terminals
are electrically connected inside the instrument.