Wiring The Circuit Under Measurement When Using A Voltage Or Current Transformer - YOKOGAWA WT332E User Manual

2.11 Wiring the Circuit under Measurement When
Using a Voltage or Current Transformer
This section explains how to wire measurement cables from external voltage transformers
2
transformers
wiring clamp-type current sensors that output current.
*1 VT (voltage transformer)
*2 CT (current transformer)
To prevent electric shock and damage to the instrument, follow the warnings given in section 2.5,
"Precautions When Wiring the Circuit under Measurement."
Voltage Measurement
When the maximum voltage of the circuit under measurement exceeds 600 Vrms, you can perform
measurements by connecting an external VT to the voltage input terminal.
Current Measurement
If the maximum current of the circuit under measurement exceeds the maximum measurement range,
you can measure the current of the circuit under measurement by connecting an external CT or a
clamp-type sensor that outputs current to the current input terminal.
• WT310E and WT332E/WT333E
When the maximum current exceeds 20 Arms
• WT310EH
When the maximum current exceeds 40 Arms
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.
Current Input Terminals
• The terminals are binding posts, and the screws are M6. Either wind a wire around a screw or pass
a crimped terminal through the screw axis, and then tighten firmly with the terminal knob.
• For the dimensions of the terminal parts, see section 2.9.
• For the precautions to follow when you connect the current input terminal and the crimping terminal
and after you connect these terminals, see section 2.9.
• When the voltage of the circuit under measurement is being applied to the current input
terminals, do not touch the external current sensor input terminal. Doing so is dangerous
because the terminals are electrically connected inside the instrument.
• When connecting a measurement cable from an external current sensor to an external
current sensor input terminal, remove the cables connected to the current input terminals.
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.
IM WT310E-02EN
to the voltage or current input terminals of input elements. Also refer to this section when
WARNING
1
1 2
or current
3
4
5
6
7
App
Index
2-45