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IM CW140-E
3-4
3.3
Precautions for Wiring the Circuit
under Test
WARNING
• When wiring the instrument or the instrument is turned off, turn off the circuit under test.
It is extremely dangerous to connect or disconnect measuring lead wires without turning off
the circuit under test.
• Be extremely careful not to connect any voltage-mode circuit to the current input terminals or
any current-mode circuit to the voltage input terminals. Miswiring can result in not only dam-
age to the circuit or equipment under test but also an injury to personnel.
• Do not apply any input level higher than the following to the voltage or current input terminals.
• Maximum allowable input (continuous)
Voltage input:
600 Vrms
Current input:
250 Arms
Clamp A (96030)
625 Arms
Clamp C (96031)
* 700 Arms
Clamp B (96032)
* Refer to Section 19.2, “Specifications of Current Clamps” for details.
In addition to the maximum allowable input, the rated input levels are specified as shown
below.
Voltage ratings: 150, 300 and 600 V
Current ratings: 20, 50, 100 and 200 A
Clamp A (96030)
50, 100, 200 and 500 A
Clamp C (96031)
200, 500 and 1000 A
Clamp B (96032)
• If using an external VT (voltage transformer) or CT (current transformer), make sure the trans-
former can adequately withstand the voltage being measured.
• Be careful not to allow the secondary stage of the CT to become open-circuited while the CT is
being electrified. Otherwise, a high-voltage may develop on the secondary stage, causing
extreme danger.
• The maximum allowable input voltage range of the external input terminals (external control
input and event input terminals) is specified as –0.5 to 5.5 V.
Do not apply voltages exceeding this range, otherwise the input circuitry may be damaged.
(When wiring the input terminals, be careful not confuse them with the optional D/A output
terminals.)
• Do not use any probes or clamps other than those voltage input probes or dedicated clamps
supplied together with the CW140.
• Do not use a clamp with any non-insulated conductors.
TIP
After wiring the CW140, it is necessary to perform setting/operation for the wiring method using the
WIRING key.
SEE ALSO
Section 7.1, "Wiring," for details on how to set the wiring method.
Summary of Contents for CW140
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