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11.
Reference
This section gives troubleshooting procedures and Q&A.
11.1 Troubleshooting
If abnormal sound, odor, smoke or heat is generated from this unit, immediately turn off power. If you think the unit is in failure, check the unit
as stated below before sending it for repair.
There are differences among measurements.
Although the current value is indicated, the electric energy (integrated value) is not measured.
Measurements differ from those obtained by other instruments.
Check that MEASURE LED (
not wired or is wired incorrectly.
Check that an appropriate type of sensor is used. If the rating of the sensor in use is different from the primary current setting,
correct measurement cannot be performed.
Check the polarity and wiring of the current sensor in accordance with the following procedures.
○
○
○
Check the wiring of the voltage line.
Make sure that the wires are connected correctly to P1, P2 and P3. Check the wiring both on the unit side and on the circuit
connecting side.
Check the wiring for short-circuiting and breaking.
The current measured by this unit differs from that measured by another instrument (by more than the allowable error).
Ensure that the instrument used for comparison can indicate correctly effective values. This unit indicates effective values.
When the instrument used for comparison indicates not effective values, but mean values, if the current on the circuit to be
measured has distortion, the values obtained by the instrument largely differ from those obtained by this unit.
Make sure that the secondary side of CT is not short-circuited. When the unit is connected with our split type potential current
transformer CW-5S (L), make sure that the secondary short-circuiting switch is not set to "Short."
Only dedicated current sensors can be connected to this unit. Make sure that other current sensors are not connected.
Although values are shown on the LCD, the values cannot be monitored through communication.
When CC-Link is used:
Check that the dedicated cable is used and that the dedicated high-performance cable is not used together with the cable.
Check that the transmission line is connected correctly and electric wires are not broken.
Check that the station number (STATION) and transmission rate (B RATE) settings are proper. Make sure that the reset
switch has been pressed after settings were changed.
see page 5) on the front panel of the main body is on. If the LED is not on, the main body is
Disconnect all current sensors, and make
1
sure that the current value is 0 A while voltage
is kept input in the unit.
Connect only the side 1 of the current sensor, and check the indication.
2
Current Check that I
is correctly measured.
1
Check that the electric power is
Electric
correctly measured.
power
Reference
For 1P3W
W = Voltage, V
R-S
For 3P3W
W = Voltage, V
R-S
√3/2
Connect only the side 3 of the current sensor, and check the indication as stated in ②.
3
Points to be checked
If the current value is not 0 A, the sensor input circuit may
have been burnt out (when a general potential transformer
is directly connected), or other parts of the unit may be
defective. Consult Mitsubishi Electric System & Service
Co., Ltd. or the local distributor.
If a measurement is given on the I
the sides 1 and 3 are connected contrarily.
If the current is lower, the current sensor may be loosely
fitted.
When a minus value is displayed:
Make sure that the terminals K and L of the current
sensor are connected correctly.
Make sure that the current line is passed through the
× Current, I
current sensor in the correct direction. Check the
1
arrow direction printed on the nameplate (the arrow
× Current, I
×
mark from the power supply side to the load side).
1
(22/32)
side, the wires on
3
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